Metabólitos secundários de plantas desempenham um papel importante na defesa contra estresses bióticos e abióticos, contribuindo para a manutenção e sobrevivência da planta. Assim, uma investigação utilizando uma abordagem metabolômica possibilita o mapeamento completo das principais vias metabólicas ativas em determinadas condições de cultivo de um organismo. O objetivo deste estudo é mapear o perfil químico da espécie Piper caldense utilizando diferentes condições simuladas de estresses bióticos e abióticos e assim poder estimular a produção de metabólitos bioativos. Espécimens de P. caldense foram cultivadas em vasos e divididas em diferentes grupos e cada grupo foi separado e submetido a diferentes condições de estresse como: herbivoria (HB), alta temperatura (AT), excesso hídrico (EH), défice hídrico (DH), jasmonato de metila (JM), salicilato de metila (SM), salino (SL), bem como um grupo controle. Após cada estresse, foi realizada a extração do óleo essencial através da técnica de hidrodestilação, seguido da análise por CG-EM. Os resultados das composições químicas foram comparados através de técnicas multivariadas, como PCA e rede molecular. Os compostos majoritários identificados para o óleo essencial da planta controle foram o E-cariofileno (10,28%), germacreno D (17,37%) e biciclogermacreno (16,91%). Por outro lado, na composição química do óleo essencial de P. caldense nas condições de estresse JM e HB o metil eugenol foi o composto majoritário com 52,78 e 55,12%, respectivamente. A classe dos fenilpropanoides se destacaram nesses dois estresses. O estudo da PCA revelou diferenças significativas na composição química dos óleos essencial de P. caldense nas diferentes condições de estresse tendo em vista que a análise estatística ANOVA revelou um valor de P igual a 1,72-31. Redes moleculares foram geradas com base nas similaridades espectrais entre os componentes do óleo essencial de P. caldense em todas as condições de estresse e controle. O bioensaio de toxicidade residual sobre a Plutella xylostella foi realizado com o óleo essencial das plantas na condição CT e submetidas ao estresse com HB, bem como com o composto isolado metil eugenol e com o inseticida comercial Azamax®. Com a análise do bioensaio, determinou-se as seguintes concentrações letais média (CL50), 23,85 μL/mL (CT), 9,89μL/mL (metil eugenol) e 2,92 μL/mL (Azamax®). Também foi realizado o teste de inibição sobre a enzima acetilcolinesterase com o óleo essencial das plantas na condição CT e submetidas ao estresse com HB, JM, bem como com o composto isolado metil eugenol e com o controle positivo cloridrato de donezepila. A análise desse teste determinou a concentração inibitória média (CI50) para cada uma das condições 8,10 μg/mL (CT), 39,91 μg/mL (HB), 18,28 μg/mL (JM), 28,51 μg/mL (metil eugenol) e 7,89 μg/mL (cloridrato de donezepila). Com esses resultados, pode-se observar que os óleos essenciais bem como o metil eugenol não atuam sobre a enzima acetilcolinesterase pois possuem uma CI50 maior que a do controle positivo. Por fim, foi realizado o teste de toxicidade sobre a Artemia salina, com o óleo essencial de P. caldense nas condições CT, HB, JM, composto isolado metil eugenol e com o inseticida comercial Azamax®. Com isso, observou-se que apenas o inseticida comercial apresentou toxicidade sobre a A. salina. Desse modo, pode-se verificar que os estresses bióticos e abióticos causam modificações quantitativas e qualitativas na composição química do óleo essencial de P. caldense, podendo esse, ser um potencial inseticida para o controle de P. xylostella.

Currently, organic synthesis has been one of the main routes used to obtain new molecules that may have biological activities of commercial interest in the fields of medicinal chemistry or agronomy, since it allows the formation of a wide variety of substrates with different chemical structures that can act as complex drugs or crop protection products. In this sense, 2,3-unsaturated O-glycosides have attracted the attention of several scientists around the world due to their ability to present broad-spectrum biological activities, as well as their greater biocompatibility with different organisms. In this way, the present work carried out the synthesis of six new 2,3-unsaturated O-glycosides 74 a-d, 75 and 76 from the reaction of 3,4,6- tri-O-acetyl-D-glycal with different alcohols using montmorillonite K-10 as the Lewis acid, basic hydrolysis and oxidation reaction, where they were obtained with yields ranging from 41% to 89% and reaction times in the order of 3 to 4 hours. The structures of the isolated compounds were elucidated using IV-FT and 13C and 1H NMR methods. The toxic activity of the acetylated compounds 74a-d was tested against adults of the spider mite (Tetranychus urticae). The results of the bioassay showed that all the 2,3-unsaturated O-glycosides had lethal toxic activity against the insect. Compound 74d was the most lethal of the treatments with a CL50 of 2.93 (95% C.I = 2.64 - 3.20), but when comparing the 2,3-unsaturated O-glycoside with its alcohol of origin, it was observed that compound 74b had a CL50 of 4.94 µg/mL (95% C.I =4.14-5.72) and a toxic activity 21.8 times greater than its non-glycosylated monoterpene alcohol. From these results, it can be concluded that 2,3-unsaturated O-glycosides containing a terpene unit as an aglycone have great potency against the spider mite.

We studied the formation of new 2,3-unsaturated O-glycosides via Ferrier rearrangement using electronic structure calculations at the B3LYP/6-31g+, B3LYP/LAN2DZ, PBEPBE/6-311g, Hartree-Fock/6-311g and AM1 levels. We analyzed some factors that may induce the majority formation of the α-anomer by Ferrier rearrangement, such as the contribution of hyperconjugation, repulsion of the acetoxy group with the nucleophile and the formation of ankimeric assistance intermediates. Based on the total electronic energy and the Gibbs free energy, it was possible to indicate the formation of an intermediate stabilized by anochemical assistance at C3, which explains the preferential formation of the α-glucoside. The results show a higher binding energy between the nucleophile and the acetoxy group at C6 in the upper region for the formation of the β-glucoside, which corroborates and justifies the argument for the formation of the ankimeric assistance intermediate at C3 on the upper side, contradicting the hypothesis that the nucleophile is repelled by the acetoxy group. Analyzing the charges before and after the formation of the 2,3- unsaturated O-glycosides shows that the hyperconjugation model of the anomeric effect is not a decisive factor for the preferential formation of the α-anomer. Finally, of all the factors, the most plausible factor favoring the preferential formation of the α anomer is the spontaneous formation of the intermediate at C3, which prevents the formation of the β anomer.

The phenomenon of multidrug resistance has led to many failures in cancer therapy. Consequently, the development of antineoplastic bioconjugates that can circumvent this phenomenon is necessary. Therefore, the objective of this work is to produce, characterize, evaluate the toxicological aspects, and verify the antitumor activity in an animal model of a new formulation with antineoplastic potential based on oxaliplatin and levan. The synthesis of the platinum precursors, potassium hexachloroplatinate and potassium tetrachloroplatinate, was performed with satisfactory yields (95.6 and 92.3%), and the formation of the compounds was confirmed by X-ray diffraction, with 99.9+% agreement according to their respective crystallographic data. Oxaliplatin was also synthesized using a viable approach, yielding 86.4%. FTIR confirmed the formation of the compound, showing absorption values for the N-H bond stretching at 3209 and 3159 cm-1; C=O and C-O bond stretching at 1658 and 1226 cm-1; and Pt-N bond stretching at 573 cm-1 . 1H and 13C nuclear magnetic resonance data also confirmed the formation of oxaliplatin. X-ray diffractometry also demonstrated the formation of the product, with 99.9+% agreement with its crystallographic chart. Levan was produced, purified, and characterized. 1H and 13C nuclear magnetic resonance data confirmed the presence of the polysaccharide, with five hydrogen signals in their respective chemical shifts and six carbon signals consistent with the furanose ring. The conjugate (SVN7) was formulated with oxaliplatin and oxidized levan in some fructose monomers, enhancing its pharmacological performance. Vibrational spectroscopy evidence reveals the formation of the product, characterized by the presence of C=O and Pt-N bond stretching bands at 1608 and 538 cm-1, as well as the N-H bond bending band at 1510 cm-1. The acute oral toxicity study in an animal model followed the OECD 423 protocol, classifying the platinum conjugate SVN7 as category 5, indicating low toxicity, with an LD50 greater than 2000 mg kg-1. Furthermore, liver toxicity parameters (AST and ALT) were also monitored, revealing that the tested composition does not induce liver damage. The antitumor activity study in an animal model was also performed in male Swiss mice inoculated with Ehrlich carcinoma. The results demonstrated high efficacy of the tested formulation, with 94% inhibition of tumor mass. The animal model assays proved accurate, demonstrating the therapeutic potential of the platinum conjugate in cancer therapy.

Cancer is one of the deadliest diseases in the world, mainly due to chemotherapy treatment, which has low selectivity and high toxicity involved. Thus, the study of new compounds that present fewer side effects associated with their chemotherapeutic use is necessary, and in this context, ruthenium(III) compounds have stood out. By combining these metal ions with ligands of low toxicity, antitumor activity, and biocompatibility, such as glycosides, an overexpression of associated effects of an antineoplastic nature is expected, but with under expression of toxicity. The aim of this work is to develop ruthenium (3+) complexes containing 2,3-unsaturated O-glycosides and analogues as ligands that show high antitumor activity and low side effects. To this end, an unprecedented 2,3-unsaturated O-glycoside was synthesized from Tri-O-Acetyl-D-glycal, which was used as the ligand for the complex coded as [Ru(glyco)2(H2O)2], where glyco is the glycoside containing malic acid as an aglycone. By way of comparison, the complex containing the malate ion as a ligand was synthesized, which was coded as Na[Ru(MA)₂(H₂O)₂], where MA = malate ion. The complexes and their precursors were characterized using spectroscopic techniques and mass spectrometry. The infrared spectroscopy results showed the presence of OH, C=O and CO functional groups in the free ligands and in the complexes in characteristic regions. The peaks referring to the CO and C=O stretching vibrations of the complexes were shifted to lower wavenumbers when compared to the same peaks of the free ligands, suggesting coordination to the metal ion. In addition, the spectrum of the complexes showed bands at 764 cm^-1 characteristics of Ru-O stretching. The ¹H and ¹³C NMR spectra of the tri-O-acetyl-D-glycal and the O-glycoside showed characteristic signals, which helped in the structural elucidation of the compounds. From the electronic absorption spectroscopy of the complexes, it was possible to observe changes in the electronic profile in relation to the free and coordinated ligand, which suggests the formation of the ruthenium-ligand coordinative bond. Mass spectrometry confirmed the minimum formula of the O-glucoside and the synthesized Na[Ru(MA)₂(H₂O)₂] complex. Thus, with the confirmation of the formation of the complexes, it is possible to begin the study of antitumor activity.

In recent years, the pharmaceutical sector has experienced significant economic growth, driven both by increased drug consumption and by increased investment in Research and Development (R&D) of new drugs, aiming to meet emerging therapeutic demands. This scenario has promoted significant advances in pharmaceutical innovation processes, resulting in the implementation of highly consolidated strategies, such as high-throughput screening (HTS), based on genomic approaches, molecular and structural biology, as well as molecular modeling. The discovery and development of new drugs represent substantial challenges for the pharmaceutical industry, due to increasing toxicity, high operational costs and the exponential increase in resistance acquired by pathogens and neoplastic cells to conventional drugs. In this scenario, the search for innovative bioactive compounds becomes essential. Among the various classes of heterocyclic structures with therapeutic potential, oxadiazoles stand out for their wide range of biological activities, including anti-inflammatory, antitumor, antifungal and antioxidant properties. The present study aimed to synthesize, characterize the structure, and evaluate the biological activity of 3,5-disubstituted 1,2,4-oxadiazoles obtained from ethyl 2-oxopropanoate and ethyl 4-oxopentanoate. The synthesis was carried out by microwave irradiation, an advantageous method for reducing the reaction time, eliminating solvents, and facilitating purification. The compounds were obtained in yields ranging from 53% to 91%. The pharmacokinetic properties were evaluated in silico by ADMETlab, revealing promising profiles. Biological assays indicated variable activities. In addition, molecular docking and prediction studies by PASS Online confirmed the potential of the 1,2,4-oxadiazole nucleus as a candidate for new bioactive entities.

The high drug consumption during festive periods, combined with the limited removal of drugs
of abuse in wastewater treatment plant and the direct discharge of domestic effluent into rivers,
can result in the release of drugs of abuse (DOA) into aquatic environments. In this study, a
multi-analyte method was developed to determine the six analytes cocaine (COC),
methamphetamine (METH), 3,4-methylenedioxymethamphetamine (MDMA) and the
metabolites benzoylecgonine (BE), cocaethylene (COE) and 11-nor-9-carboxy-∆9-
tetrahydrocannabinol (THC-COOH) in surface water from the Beberibe and Tejipió rivers. The
sample preparation method was optimized using a full factorial design of 2 3 to evaluate the
parameters of sample volume, conditioning/elution solvent and washing step of the Strata-X
cartridges. Instrumental analysis was conducted using gas chromatography coupled to mass spectrometry (GC-MS). After optimization, the method was validated for linearity, precision,
accuracy and limit of quantification (LOQ) and applied to 18 surface water samples collected
during Carnival and during non-event periods. COC and BE were detected in 100% of the
samples, with maximum concentrations of 951.6 ng L-¹ and 744.1 ng L-¹, respectively, in the
Beberibe River during Carnival. The metabolite THC-COOH was identified in 72% of the
samples, with a maximum concentration of 177 ng L-¹ during the festive period. MDMA was
quantified in 38% of the samples, with a maximum concentration of 19.3 ng L-¹. The risk
quotient (RQ) analysis indicated that, for most of the substances, there was no considerable risk
to aquatic life. However, RQ values higher than 0.1 were observed for THC-COOH and COC,
suggesting a moderate risk to aquatic organisms. However, RQ values higher than 0.1 were
observed for THC-COOH and COC, suggesting a moderate risk to aquatic organisms, thus
highlighting the importance of monitoring contamination in aquatic systems during festive
events.

Heterocyclic compounds are molecules that contain a heteroatom in their
structure, forming 5- or 6-membered rings. Generally, this heteroatom can be
nitrogen, oxygen or sulphur. These compounds are of great importance in
synthetic and medicinal organic chemistry, accounting for approximately 75% of
the published works. Among the vast class of heterocyclic compounds, those that
contain nitrogen in their structure deserve special mention, also known as
nitrogenated heterocycles or N-heterocycles. The presence of the nitrogen
heteroatom enables these compounds to interact easily with macromolecules,
such as proteins, enzymes and DNA, imparting them with diverse biological
properties, as documented in the literature, including antimicrobial, antiviral,
anticancer and anti-inflammatory activities. In the design and development of new
biologically active compounds, it is common to incorporate one or more
heterocycles, which provides these compounds with advantages, such as the
potential to expand the spectrum of biological activity. In the first chapter, we
carried out the copper-catalysed cycloaddition reaction to link phthalimide rings
with pyrimidine bases, conjugated to the isomers of 1,2,3-triazole 1,4-
disubstituted, containing 3 or 5 heterocyclic nuclei, with biological evaluation of
some compounds against SARS-CoV-2. In the second chapter, we performed the
diastereoselective arylation of the bis-lactim ether with a wide range of aryl
chlorides via palladium-catalysed asymmetric synthesis, also obtaining arylated
glycine. As a result, new N-heterocyclic compounds were obtained via two distinct
routes, with promising biological potential.

Tetranychus urticae (Koch) is a cosmopolitan and polyphagous pest, considered one of the main agricultural pests worldwide. Its control is mainly carried out by the application of commercial acaricides such as Orthus® and Azamax®, which cause environmental contamination, damage to non-target organisms and contribute to the development of resistant populations of the pest. As an alternative to commercial mites, botanical acaricides based on essential oils (EOs) and their main constituents have been used to control T. urticae. In this way, the search for new alternatives based on EOs and compounds derived from them is important to minimize the emergence of resistant populations. The properties observed for EOs are attributed to their main constituents. However, the property observed for a given oil cannot be attributed solely to the majority constituent since the toxicity of the oil can be increased due to interactions between the constituents in smaller percentages. At this stage of the work, the toxicity of more than 50 compounds from the monoterpene class (α-pinene and geraniol), phenylpropanoid (safrole) and diterpene (phytol) was evaluated. Among the compounds tested, phytol revealed the greatest toxicity against T. urticae, with a mortality of 100% at a concentration of 0.5μL/mL. Tests were carried out to investigate the lethal and sublethal acaricidal potential, through the residual and ovicidal contact bioassay of binary mixtures obtaining medium lethal (LC₅₀) and sublethal concentrations, evaluating hatching and oviposition against the two-spotted mite. All compounds and binary mixtures were shown to be toxic to T. urticae through the residual contact bioassay, with the best results observed for the mixtures 30% phytol and 70% safrole (LC₅₀= 2.16 µL/mL), 10% phytol and 90% safrole (LC₅₀= 3.38 µL/mL). For the bioassay of ovicidal residual contact mixtures, all binary mixtures acted strongly on the eclosion of T. urticae, within 48 hours.

Plutella xylostella is a pest that causes damage to Brassica production in Brazil and around the world. Its control is carried out by applications of synthetic insecticides, but due to the pest's ability to adapt and resist, larger and more frequent doses are increasingly necessary, resulting in several environmental problems. Alternatively, formulated with extracts and essential oils from plants such as Lippia gracilis, Ocimum basilicum var. minimum and Ocimum gratissimum, have been identified as potential natural insecticides. However, it is known that the chemical composition of these products from plants can vary according to external factors. In this way, an investigation with a metabolomic approach allows identifying the ideal condition to stimulate the production of bioactive compounds with potential insecticides. Thus, the objective of this work was to enhance, through simulated conditions of biotic and abiotic stresses, the production of bioactive metabolites in specimens of L. gracilis, O. basilicum and O. gratissimum. The stressed plants were analyzed using metabolomic techniques and their obtained oils were evaluated for their toxicity to control P. xylostella. The species were cultivated under controlled conditions, divided into groups and subjected to different stresses: Manual predation (PM), methyl jasmonate (MJ), methyl salicylate (SM), ultraviolet (UV), herbivorous predation (PH), water scarcity (EH), excess water (ExH) and no stress plants (Control). The oils were obtained through hydrodistillation. The chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS). The results of the oils were analyzed using the statistical techniques of PCA, Heatmap and molecular network. Insecticidal activity was evaluated using the mean lethal concentration test (LC₅₀) and inhibition of the enzyme acetylcholinesterase (AChE). The PCA, Heatmap and molecular network studies highlighted qualitative and quantitative differences in the chemical composition of the oils. Carvacrol was the majority constituent in all L. gracilis oils, with a higher percentage under UV stress (64.12%). For the species O. basilicum, (E)-methyl-cinnamate was identified as the major constituent in all oils, with the exception of species stressed by PH (43.48%) and ExH (40.18%), which revealed methyl chavicol as majority constituent. For O. gratissimum oil, eugenol was the majority in all oils. However, a significant increase in the percentage of γ-himachalene was observed for UV-stressed species (21.23%). All oils showed insecticidal activity against P. xylostella. The oils also showed activity on the acetylcholinesterase enzyme, with emphasis on the oils stressed by PM from the species L. gracilis and O. gratissimum and the oil stressed by MJ from the species O. basilicum. Therefore, it was found that biotic and abiotic stresses cause quantitative and qualitative changes in the chemical composition of the EOs of the species studied and also differ in the insecticidal activities tested.

The aim of this work was to synthesize 1,4-naphthoquinones containing an imidazole heterocyclic nucleus. Initially, 2,3-dibromo-1,4-naphthoquinone (49b), 2-bromo-1,4-naphthoquinone (49a) and different arylamidoximes (9a-g) were synthesized. In the first stage, the reaction between compound 49b and arylamidoximes 9a-g took place, resulting in seven new compounds containing the oxadiazine core 51a-g, obtaining yields of 59-84%. Using compound 49a in the reaction with arylamidoximes 9a-g, another seven novel compounds were obtained, 53a-g, showing yields of 62-94%. In the second part, the oxygen of the arylamidoximes was protected with benzoyl chloride, leaving only the amino group available, in an attempt to reach intermediate 56a and, subsequently, the imidazole ring. However, it was not possible to reach intermediate 56a due to the cyclization of compound 57a.

Several essential oils have insecticidal activity, such as M. leucadendra oil, which contains (E)-nerolidol as the main compound. This compound has several biological activities such as: antimicrobial, anti-inflammatory, insecticidal and acaricidal. As (E)-nerolidol can be obtained naturally through M.leucadendra oil and this compound already has acaricidal activity, changes in its structure can promote better enhancement of this activity. Some reactions already reported in the literature that promote greater toxicity to the molecule's mechanism of action were tested on the (E)-nerolidol molecule, such as hydrogenation, acetylation, silylation and also epoxidation reactions. The reactions showed expected yields and the compounds could be characterized. Compared to the acaricidal effect of the substrate (E)-nerolidol, the hydrogenated compound (E)-nerolidol derived from the hydrogenation reaction presented a greater toxic effect on the two-spotted mite. The compounds were also subjected to the acetylcholinesterase (AChE) enzyme inhibition test, which, when inhibited by insecticides, can cause the accumulation of acetylcholine in synapses, leading to fatal consequences such as muscle paralysis, coma and death of pests (MENOZZI, P, et al, 2004). However, semi-synthetic compounds that do not inhibit AChE can be advantageous in the use of insecticides, as they do not cause harm to humans. The ones that showed the best results were (E)-nerolidol/Silylated and Acetylated/epoxidized, compared to the positive control Donezepil hydrochloride.

Water contamination caused by anthropogenic actions generates socio-economic and health problems, directly affecting the quality and availability of water. In Brazil, only 56% of the population has access to an adequate sewage treatment system, reflecting the significant deficiencies in basic sanitation. Microbiological assessments and analysis using biomarkers such as sterols can estimate the level of contamination in an environmental system. This study investigated the impact of anthropogenic actions on the contamination by domestic sewage of a stretch of the Capibaribe River in Recife/PE, associated with a sewage treatment plant (STP) and the period during which it was under maintenance, based on the quantification of sterols by GC/MS. The analytical workflow included the collection of 1 liter of 12 surface water samples from the Capibaribe River, the removal of particulate organic matter (POM), the analysis of total and thermotolerant coliforms, and the identification and quantification of sterols. The validation of the method followed ANVISA and INMETRO guidelines, meeting the figures of merit of linearity, LD, LQ, and instrumental precision. The process was validated by ANVISA and INMETRO guidelines, meeting the standards of linearity, LD, LQ, and instrumental precision. According to CONAMA legislation, the concentration of thermotolerant coliforms was above the ideal for a class 2 water source due to the deposition of fecal microbiological agents. This study quantified coprostanol, the principal fecal indicator, in all the samples, revealing that the site associated with the presence of the WWTP had relative values of 73%. The diagnostic ratios applied helped to identify the possible sources of this contaminant. Statistical analyses, such as Pearson Correlation (PCC) and Principal Component Analysis (PCA), were used to investigate the correlations between sterols and potential sources. Thus, this study contributes to the environmental monitoring of the region and can support the adoption of measures for the recovery of the Capibaribe River in the central area of Recife.

The use of nanoemulsions for incorporating essential oils as active principles has been increasingly evidenced. Controlled release systems targeted for agricultural applications against pests that cause significant economic losses are becoming more commonly applied, considering that essential oils have some characteristics that limit their applications. Oxidative degradation, low solubility, soil residues, and excessive applications are some of the main reasons driving the search for an alternative controlled release system. Nanoemulsions (NE) are defined as dispersions of droplets with diameters below ~500 nm (0.5 μm), giving a clear or translucent appearance, characterized as thermodynamically unstable dispersions of oil and water formed mechanically. This study aims to develop nanoemulsions with essential oil of Melaleuca leucadendra and the compound (E)-nerolidol, evaluating the physicochemical stability of the nanoemulsified essential oil and its acaricidal activity against the pest Tetranychus urticae. In the formulation development, concentrations of 10% and 20% of the essential oil/compound were used, with various combinations of non-ionic surfactants such as Span 80® - Sorbitan Monooleate and Tween 80® - Polysorbate. The best formulation responses for the essential oil and the compound (E)-nerolidol were obtained with a 10% concentration. The nanoemulsions in proportions ML4 and NE4 (oil and compound, respectively) were the most stable as they remained homogeneous during stability tests. The best encapsulation percentages under stress conditions were under UV radiation, where the oil nanoemulsion showed 68.77% and the compound nanoemulsion 93.09%. The nanoemulsions in proportions ML4 and NE4 were toxic against the pest Tetranychus urticae through the residual contact bioassay, in which mites are placed on treated leaves, presenting LC₅₀ = 4.96 μL/mL (ML4) and LC₅₀ = 5.39 μL/mL (NE4). In the repellency bioassay, the essential oil nanoemulsion showed activity at all tested concentrations, with the best result at LC₁₀ = 0.84 μL/mL compared to Azamax®.

The increasing emergence and spread of arboviruses, such as those responsible for diseases such as dengue, Zika, chikungunya and yellow fever, have been accelerated by the ability of vectors, mainly the Aedes aegypti mosquito, to sustain transmission between humans. This ability is amplified by the adaptation of arthropods to urbanization, which eliminates the need for their forest cycles and natural reservoirs. Given the absence of a single and effective strategy to control these vectors, organic chemistry plays a crucial role in the synthesis and isolation of new molecules that can act as control agents. In this study, the objective was to synthesize and characterize different O-alkylated amidoximes and evaluate their larvicidal potential against Aedes aegypti. The synthesis of amidoximes was carried out by the reaction between hydroxylamine hydrochloride and benzonitrile, using a hydroethanolic medium and sodium bicarbonate, with mechanical stirring at room temperature (25±2 ºC). The optimization of the reaction conditions for the O-alkylation of amidoximes involved the analysis of different parameters, such as temperature, energy input and basic species. The most efficient condition, which resulted in the best yields, was the use of mechanical energy (45±5 °C) with KOH as the basic species and DMSO as the solvent. After synthesis, the amidoximes were purified by crystallization in chloroform and hexane, while the O-alkylamidoximes were purified by glass column chromatography. The purification yields ranged from 43% to 87%. Subsequently, they were characterized by Infrared (IR) and Hydrogen and Carbon Nuclear Magnetic Resonance (¹H and ¹³C NMR) spectroscopic methods. In the next step, larvicidal tests were performed to evaluate the efficacy of the new molecules against Aedes aegypti larvae. Of the ten amidoxime derivatives tested, two stood out with promising larvicidal activity. 4-Bromo-O-(2,2-diethoxyethyl)benzamidoxime showed an LC₅₀ value of 247.58 ± 5.09 ppm, while 4-O-(2,2-diethoxyethyl)pyridinamidoxime obtained an LC₅₀ value of 198.44 ± 11.52 ppm. These results indicate that these compounds have significant potential for the control of Aedes aegypti and, consequently, for the mitigation of diseases transmitted by this vector.

Mechanisms of bimolecular reactions in the gas phase can be studied from the perspective of theoretical and computational chemistry through the static methodology that uses the energetics of potential energy profiles together with statistical theories (TST and RRKM) to analyze and interpret the reaction channels and through of Born-Oppenheimer molecular dynamics (BOMD) via simulation of quasi-classical trajectories. The electronic structure methods employed were those based on the second-order Møller-Plesset perturbation theory (MP2), for the description of PEP in the S_N2 reaction, and on the density functional theory (DFT), with the hybrid double functional B2PLYP to simulate dynamics trajectories, aiming to investigate the thermal, isotopic and dipole orientation effects. For both approaches, a basis set of Pople were used. For the thermal and isotopic effect, the studied system was , in which a post-TS - sampling was performed; while for the purpose of dipole orientation, we started with isolated reactants. For investigations of the thermal effect, the temperatures sampled were from 300 to 1000 K, and 800 dynamic trajectories were calculated, which sought to evaluate the energy flow of the rotational modes of the system, since, in previous studies, it was verified that the incapacity of the system  following an IRC path arises from the vibrational periods for the bending of the  mode, implying little rotational energy in the HXCH₃ fragments. In this sense, the influence of temperature on roto-vibrational coupling was investigated. The preliminary results point to a weakening of this coupling at higher temperatures, consequently, a smaller number of trajectories that lead to the formation of a product complex (CP), which is classified as an IRC (Intrinsic Reaction Coordinate) trajectory. In the isotopic effect, 8 systems were studied with 100 trajectories for each system, totaling 800 dynamic trajectories. In this step, we intend to investigate whether isotopic systems of greater mass make the bending of the  mode slower to obtain more time needed to change the  angle (180° to 80°) in order to make the formation of the hydrogen bond that configures the characteristic CP of an IRC behavior is adequate. Additionally, 2700 dipole orientation trajectories, which started from three different orientations (0°, 90° and 180°) of the dipole along the  axis. Results of the isotopic effect and dipole orientation are still under analysis.

The identification of human disease biomarkers such as methylated DNA adducts in biological samples is of great importance. In this context, the main objective of this work was to investigate, for the first time, the electrocatalytic oxidation of 7-methyl-guanine (7-mGua) and 5-methyl-cytosine (5-mCyt) in a boron doped diamond electrode pre-tretaed cathodically treated (red-BDDE), using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The anodic peak potentials of 7-mGua and 5-mCyt by DPV were observed at E = 1.04 V and E = 1.37 V at pH = 4.5, indicating excellent peak separation of approximately 330 mV between species . Using DPV, experimental conditions such as supporting electrolyte, pH and influence of interferents were investigated to develop a sensitive and selective method for the individual and simultaneous quantification of these biomarkers. The analytical curves for the simultaneous quantification of 7-mGua and 5-mCyt in acidic medium (pH = 4.5) were: concentration range of 0.50–5.00 μmol L-1 (r = 0.999), limit of detection of 0.27 μmol L-1 for 7-mGua; and from 3.00 to 25.00 μmol L-1 (r = 0.998), with a detection limit of 1.69 μmol L-1 for 5-mCyt. A new method from DPV for the simultaneous detection and quantification of the biomarkers 7-mGua and 5-mCyt using red-BDDE was then proposed. The electrooxidation of 3-methyladenine (3- mAde) in aqueous electrolytes on carbon electrodes (GCE and red-BDDE) was investigated by voltammetric techniques and electrochemical impedance spectroscopy (EIS). Different experimental factors were explored, such as the influence of concentration, composition and pH of the medium, mass transport, adsorption of products on GCE and BDDE surfaces and the presence of possible interferences in the oxidation of 3-mAde. The electrochemical data demonstrated that the methyl group is not electroactive, but strongly influences the oxidation mechanism of 3-mAde. The anodic behavior of 3-mAde on GCE and BDDE occurred by mass transport by diffusion, in a single irreversible pH-dependent step, in a reaction at the electrode with the removal of an electron and a proton. By cyclic voltammetry, the diffusion coefficient of 3-mAde was established at physiological neutral pH (D3-mAde = 1.57∙10-5 cm2 s -1 ). Compared to adenine, the oxidation of 3-mAde occurred at more positive potential values (~200 mV), thus allowing simultaneous voltammetric determination of both bases. Recovery experiments were performed and additions of 3-mAde with known concentrations were made to samples prepared from mixtures of free DNA bases and the 7-mGua adduct. The results on the GCE sensor in acetate buffer (pH = 4.5) were quite satisfactory (96.4 – 101.3% recovery), indicating excellent precision and accuracy, as well as advantages such as simplicity, speed and cost of the proposed method. New methods with GCE and red-BBE using DPV to determine 3-mAde in acetate buffer (pH = 4.5) and phosphate buffer (pH = 7.0) were also proposed. Thus, overall this work proposes new sensitive and selective electrochemical sensors, using DPV and functionalized carbon electrodes for the simultaneous detection and quantification of important biomarkers of human diseases, such as 7-mGua, 5-mCyt and 3-mAde, contributing significantly to the advancement of electroanalytical techniques in biomedical research.

Moringa oleifera  Lam. (M. oleifera ) is a plant native to Northwest Asia that has gained notoriety due to its nutritional richness and versatile applications, especially observed in the leaves of this plant. However, despite this, there is still a scarcity of studies focused on the development of food products and their potential impact on food security. In light of this scenario, the present study aims to develop and analyze the quality parameters of M. oleifera  leaf flour obtained via microwave oven (MWO), verify its stability under different storage conditions, develop a fortified food product, and evaluate the effects of flour consumption during pregnancy and lactation in an animal model. Initially, a literature review was conducted evaluating the botanical, chemical, and nutritional characteristics of M. oleifera  leaves and their economic scenario over the last 10 years (2014-2024), through research in Web of Science, Scopus, Scielo, ACS publications, and Pubmed databases. Experimentally, the development of a flour product from the leaves was carried out through drying in MWO and oven, evaluating the physicochemical parameters (moisture, pH, ash, water activity, protein, crude fiber, lipids) of the products obtained. The drying kinetics were performed under three different conditions in MWO (50%, 70%, and 100%) and in a forced air oven (50°C, 60°C, and 70°C) using 10 mathematical models. Subsequently, the storage study of the leaf flour obtained in MWO was carried out, packaging it in laminated zippered metallic containers suitable for storage in a BOD incubator with fixed temperatures of 20ºC, 30ºC, and 40ºC, respectively, analyzing the physicochemical and colorimetric characteristics of the product at 0, 30, 60, and 90 days. The fortified cheese bread was obtained by adding 1%, 1.5%, and 2% M. oleifera  leaf flour to the conventional cheese bread dough, prepared in an electric oven at 180°C for 40 minutes and nutritionally analyzed. For the study of the effects of M. oleifera  consumption, the effects of leaf and seed flour were evaluated in 27 Wistar rats and 39 offspring, divided into three groups (control, leaf, and seed), with the mothers receiving daily supplementation of the flour products via gavage at a concentration of 100 mg/kg of the animal, following the dilution of 1 g/10 mL. Maternal weight gain and feed intake, maternal biochemical parameters, neonatal parameters, physical development, sensory development, memory, and anxiety tests of the offspring were analyzed. The results showed that the M. oleifera  leaf is considered the most nutritious part of the plant due to its rare combination of nutrients (proteins, fibers, minerals, vitamins) and bioactive compounds with numerous health benefits. Moringa leaf flour is considered the most important product sold from this plant, accounting for about 30% of total sales, with growth projections in the coming years. In the product development, it was found that higher temperatures and powers used showed better results, achieving moisture of 5.44% in 300 minutes in the air circulation oven and 5.38% moisture in 4 minutes and 30 seconds in the microwave oven, both flour products showing a high concentration of nutrients. In the storage study, it was found that the flour showed good stability under all storage conditions, but 30°C was the best storage condition, resulting in less nutrient loss, lower moisture, and more stable color. The results of cheese bread fortification were efficient in reducing product moisture and significantly increasing nutritional value, with up to a 10-fold increase in protein and fiber values in the supplemented product, maintaining the physical characteristics of the product. The administration of flour products used in the supplementation of pregnant rats during gestation and lactation brought satisfactory results for pregnant rats and offspring. Weight gain and greater satiety were observed in the supplemented maternal groups, improvement in all maternal biochemical parameters, absence of abortions and/or mutations, or modification of neonatal parameters. The offspring of the supplemented groups had anticipated sensory development compared to the control group, greater body development, better cognitive memory development, and reduced anxiety in all tests performed.

Tryptophan (TRP) can be metabolized by two distinct pathways: the serotonin pathway and the kynurenine pathway, where a large part of TRP is consumed by the latter. Studies report that the imbalance between these two pathways is associated with several types of diseases. The kynurenine pathway in which most of the TRP is consumed produces several intermediate metabolites such as kynurenine (KYN) and kynurenic acid (KYNA), that are considered biomarkers of human diseases. Therefore, this work aimed to investigate for the first time in the literature the redox properties of KYN and KYNA in aqueous electrolytes on functionalized carbon electrodes, the glassy carbon electrode (GCE) and the screen-printed carbon electrode (SPCE) pretreated anodically, using electrochemical techniques, cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS). The redox properties of similar molecules, aniline and tyrosine, were also investigated and compared in relation to the biomarkers investigated here. The results clearly indicated that KYN and KYNA were electroactive molecules and both were oxidized from complex and multistep mechanisms. The oxidation mechanism of KYN was proposed and occurs at the 2- aminobenzoyl group from a main step with the withdrawal of one electron and formation of an intermediate radical cation (KYN+•). KYN+• follows a dimerization and finally polymerization pathway (polyKYN), forming different electroactive products that are strongly adsorbed on the surfaces of carbon electrodes. The electrochemical data also indicated that the adsorbed polyKYN films on carbon electrodes in a strongly acidic medium are conductive and in a physiological medium they are resistive, hindering new subsequent reactions. All redox reactions identified were dependent on an acid-base equilibrium, since they were strongly influenced by the pH of the medium, occurring more easily in alkaline media. The oxidation mechanism of KYNA was also proposed, occurring from a main irreversible step, in the electroactive hydroxyl group, with the removal of one electron and one proton, with the formation of a radical (KYN• ). The radical, due to its high reactivity, followed two reaction routes, with water to form a para-quinone derivative and the polymerization pathway. These pathways were strongly influenced by the pH of the medium, since quinone derivatives were not detected in physiological medium. The voltammetric responses of DP and SW were also explored here for the development of sensitive electroanalytical methods for detection and quantification of these biomarkers. For the development of the proposed methods for quantification of KYN and KYNA, different analytical parameters were explored, such as working concentration range, linearity, detection and quantification limits, selectivity in relation to possible interferents, analytical frequency, accuracy and precision. A method using DPV and GCE was developed for determination of KYN in acidic medium (pH = 0.30), with a working range of 2.00 to 8.62 μmol L-1 (r = 0.997), limit of detection (LOD) of 0.54 μmol L-1 and limit of quantification (LOQ) of 1.81 μmol L-1 . For KYNA, a method was developed using SWV and SPCE, with a working range of 4.65–12.86 μmol L-1 , r = 0.996, LOD of 0.78 μmol L-1 and LOQ of 2.61 μmol L-1 . The spectrometric properties of KYN were also explored here for the development of a sensitive and selective analytical method, based on digital fluorescence imaging (FDIB), for the detection and determination of KYN in biological samples.

Trypanosoma cruzi (T. cruzi or Tc) is the unicellular protozoan parasite that causes Chagas disease. Considering the evolutionary cycle in the host, it is clear that, regardless of the form of Tc transmission, the Trypomastigote form needs to penetrate the host cell to complete its evolutionary cycle. Trypanosoma cruzi Trans-Sialidase (TcTS), an enzyme from Trypanosoma cruzi, is an example of a relevant biological catalyst for the development of the disease caused by this parasite. The essential substrate for TcTS is sialic acid (SA). The enzyme Trans-Sialidase of Trypanosoma cruzi (TcTS) removes an SA unit, initially linked to a glycoside present on the surface of the host cell, transferring the SA to another glycoside on the surface of the parasite cells, which allows the parasite to go unnoticed of our immune system and be internalized by the host cell. The already consolidated and accepted mechanism for the functioning of the TcTS follows the classic “ping-pong” model, in which the donor leaves the active site for the acceptor to enter. However, according to this hypothesis, a water molecule could easily attack the sialyl-enzyme intermediate before acceptor binding, resulting in inefficient sugar transfer. An alternative mechanism proposed by Oliveira et al. (2014), involving a ternary intermediate, defines the donor and acceptor that bind to the enzyme at the same time. The authors found evidence that, after binding of the donor (α-2,3-sialyl-lactose), a structural rearrangement occurs that opens a gap capable of holding the acceptor unit, allowing a direct mechanism without the need for the exit of the donor for the transfer. In this work, MD simulations were carried out to study the opening of the cavity close to the active site, as well as the extent to which enzymatic activity is affected by the entry of a glucose molecule into the catalytic site of TcTS, together with sialyllactose, by QM. /MM. The results suggest that the mechanism does not follow the commonly accepted ping-pong model, due to the existence of the ternary complex.

In this study, the photocatalysis of methylene blue in the presence of mixed oxide based on Ni and Al associated with silver nanoparticles was evaluated. It is suggested that the presence of metallic nanoparticles amplifies photocatalytic effects by plasmonic effects and this hypothesis led to the development of this material. The oxide was synthesized by the coprecipitation method at controlled pH, obtaining lamellar structures based on Ni and Al terephthalate, followed by obtaining the material in the form of mixed oxide by calcination. In the process, attempts were made to obtain the inclusion of Ti in the oxide, but without success. The composite in powder form was obtained from the association of mixed oxide with AgNPs previously prepared by colloidal route. The materials were characterized by X-ray diffraction, infrared spectroscopy, Zeta potential, transmission electron microscopy and scanning electron microscopy with elemental analysis. The results indicated the formation of a mixed oxide of Ni and Al with nanostructured morphology and agglomerated in the form of fine flakes. The Ag nanoparticles used are thin, with rounded morphologies, zeta potential ζ = -42.1 mV and average dimension d = 14±8 nm. The composites showed amplified photodegradation after association with AgNPs, with about 85% and 78% for UV and visible systems, respectively, while for pure NiAl oxide, degradation of 75% and 65% was observed. These results reinforce that photocatalysis assisted by Ag nanoparticles is a combination that makes the system more efficient in the degradation of persistent organic pollutants such as dyes. Furthermore, it is suggested that the negative charge on the surface of the composites favors the association of cationic dyes, making the heterogeneous photocatalysis process more efficient for this class of compounds.

The study of the effects of counter-ions of [Eu(12C4)(phen)₂(X)_n]^3-n on the europium emitting spectrum is studied theoretically. X = F^-, Cl^-, Br^-, SCN^-, NO₃^-, ClO₄^-. In the experimental study it is reported in the excitation and emission spectrum polarizability events of the anions, in which there is the maximum excitation shift and the reduction of quantum efficiency respectively. In addition to considering [Eu(12C4)(fen)₂]³⁺ a specific sensor of nitrate ions when in water. Based on this, calculations were performed with two coordination forms of the ligand X in B3LYP and M06-2X methods, defined as superior (S) and lateral (L) coordination. Then a study of the solvation process of the optimized structures. Finally, the triplet and singlet states by LC-ωPBE in the M06-2X geometries are studied. The results describe that lateral addition favors the complexation process, but when in water the F- and Br- anions invert, considering the formation of the higher form. The ion exchange for synthesis of [Eu(12C4)(phen)₂NO₃]²⁺ by the other complexes describes that synthesis of the lateral form is more likely to be formed than the top one. But the ion exchange with F^- does not occur. Regarding the excited states, two probable mechanisms of electron transfer in the complexes are described, in which, starting from the energy differences of the ligand-euron states. It relates that the non-radiative rate reduces with the loss of symmetry of [Eu(12C4)(phen)₂(X)_n]^3-n upon addition of the ligand and the emission mechanism I (T₂ → T₁ → ⁵D₀ or T₁ → ⁵D₀). This process is evidenced in the complex with [Eu(12C4)(phen)2NO3]2+. While the radiative rate and by the smaller radius (structural stability) and polarizability of the ligand. These parameters are more significant when they occur in the most stable coordination form.

The Plutella xylostella, popularly known as the diamondback moth, is the main pest that attacks oilseed species of the Brassicaceae family, such as cabbage, cauliflower, cabbage and others. These crops are responsible for great movement in the world economy and their interruption causes irreparable economic damage. The mains form of pest controls are through chemicals controls, with the application of commercial insecticides based on different chemical classes, such as carbamates, pyrethroids, organophosphates, among others.. However, the indiscriminate use of these insecticides often ends up affecting non-target organisms, in addition to contaminating the environment. As an alternative to commercial insecticides, products of natural origin such as essential oils, extracts and pure compounds have been gaining ground in the formulation of botanical insecticides. In the present work, mixtures were formulated between the essential oil of the leaves of Melaleuca leucadendra with the compounds licarin A and piplartine isolated from the leaves of Piper cyrtopodom and Piper tuberculatum, respectively. The essential oil was obtained by hydrodistillation and its analysis by Gas Chromatography coupled to Mass Spectrometry (GC-MS) revealed E-nerolidol (97.68%) as the major constituent. Both the essential oil (LC₅₀ = 0.17μL/mL), licarin A (LC₅₀ = 18.38μL/mL) and piplartine (LC₅₀ = 7.84μL/mL) were toxic to P. xylostella. The binary mixture (07:03) of M. leucadendra oil with licarin A resulted in a synergistic mixture with larvicidal toxicity of LC₅₀ = 0.13 μL/mL. The embryocidal toxicity of this mixture was performed, showing an average lethal concentration of 0.002 μL/mL. The mixture of piplartine and M. leucadendra resulted in four synergistic mixtures, in the proportions 09:01, 05:05, 04:06 and 01:09. In this way, the mixtures between the essential oil of M. leucadendra and the isolated compounds of lycarin A and piplartine proved to be active and promising as a formulation for the control of the pest Plutella xylostella.

Milkfat is a bovine milk’s component presents in dairy products that has
economic and nutritional importance, because it is a source of nutrients such as fatsoluble
vitamins and carotenoids. The noblest fraction of milk, it is a source of fat very
valuable that has been target of adulteration by some producers to reduce their costs
and maximize profits. According to the literature, due to availability and low cost, soy
and palm oils have been used as partial or total substitutes for milkfat. The addition of
a substance not declared on the label and/or not permitted by current legislation
constitutes a practice of food fraud. Cholesterol accounts for 95% of the total sterols
present in milkfat. As β-sitosterol is the sterol of vegetable origin found in greater
abundance in vegetable fats, it has the potential to be used as a marker of the presence
of vegetable fat in products of animal origin. The present work aims to describe a
qualitative method capable of identifying the addition of vegetable fat in the milkfat of
butter, creamy cheese and UHT milk cream sold in supermarkets, based on the
analysis of the unsaponifiable matter, by detection of β-sistosterol as a marker of
vegetable fat, using the HPLC-UV technique. The present work results a validated
method for the detection of vegetable fat in butter, milk cream and creamy cheese,
according to the guidelines of the Analytical Quality Assurance Manual: Areas of
Identity and Quality of Food and Inputs, publication of the Brazilian Ministry of
Agriculture and Livestock. The method evaluated in this work met the defined
validation parameters of selectivity, detection limit, repeatability and intermediate
precision. Samples of butter, UHT milk cream and creamy cheese from different brands
were acquired for analysis, from which two brands of butter and one brand of UHT milk
cream adulterated with vegetable fat were identified.

Plutella xylostella L. is one of the main agricultural pests that attacks cruciferous crops around the world. This pest has developed resistance against almost all commercial chemical insecticides, making it one of the most problematic field pests in Brazil. The species Brassicas oleracea L. of the brassicaceae family is the main target of this pest, as it affects cabbage, broccoli and kale plantations, causing damage to the final product. Because of this, there is a battery of insecticide applications for its control, causing damage to the producer, contamination above the limit allowed in food and soil. Natural essential oils from plants can be a safe alternative for agricultural pests. The development and production of essential oils lessens the negative effects of synthetic chemicals. This work aims to investigate the insecticidal potential of essential oils from the leaves of different species of Protium, on the cruciferous moth, Plutella xylostella, in addition to reporting its antioxidant action and chemical composition. The oils exhibited yields ranging from 0.04% to 0.30%, in addition to being identified with a high sesquiterpene profile. Spathulenol (32.76%) was identified as the major constituent in the oil of P. aracouchine, whereas β-caryophyllene was the main constituent in the oil of P. giganteum (27.70%) and P. heptaphyllum (22.38%). Caryophyllene oxide (46.0%) was identified as the main constituent of P. ovatum oil. Bicyclogermacrene was identified as the main constituent of the oils of P. grandifolium (26.77%) and P. tenuifolium (23.98%). In the DPPH˙ test, P. heptaphylum oil showed a greater potential for antioxidant activity. For the test with the ABST˙+ radical, P. giganteum oil was the most promising among the other oils. The results obtained through the larval toxicity bioassay showed that the oils of P.ovatum, P. aracouchine and P. giganteum were toxic against P. xylostella larvae. The oil from the leaves of P. ovatum was 3 times more toxic compared to the other analyzed oils.

The present work brought studies related to Attalea maripa (Aubl.) Mart, a palm tree
native to the North, Northeast and Midwest regions of Brazil, located in the Amazon biome. O
objective was to trace the chemical profile (leaf and pulp), evaluate the antiradical activity
of the parts of the palm tree (leaf, bark and pulp) and the physical-chemical analysis (pulp and leaf). To the
samples were submitted to techniques such as high performance liquid chromatography (HPLC),
gas chromatography coupled to mass spectrometry (GC-MS), magnetic resonance
(NMR) and infrared (IR) spectroscopy, in addition to antiradical studies by
DPPH• and ABTS•+ method and assays for total phenolics and flavonoids. The compound profile
was obtained through ethanol extracts and hexane partitions, ethyl acetate and
methanol:water (1:1). The partitions were submitted to column chromatography, highlighting
for the methanol:water fraction of the leaf and the methanolic extract of the pulp. through techniques
using HPLC, GC/MS, IR and 1 H and 13 C NMR, the presence of polysaccharides and acids is assumed
fatty acids, respectively, in the leaf and pulp fractions, identifying alkanes, alkenes and acids
carboxylic acids through IV analyses. The phenolic and flavonoid contents were shown to be
significant in ethanolic extracts and in the acetate part of the leaf, bark and pulp and it can be
observe that they influence the antioxidant capacity of the tests made of DPPH and ABTS. You
results of the centesimal composition analysis of the pulp revealed 41.38% of moisture, pH
4.96, 9.7% total soluble solids, 1.2% total titratable acidity, 5.90% ash, 28.19
% lipids, 4.55% proteins, 7.94% total sugars, 2.13% reducing sugars and
5.52% of non-reducing sugars. The leaf showed pH 6.29, 4.96% ash and 7.94%
lipids. A colorimetric test characterized the flesh color as light and vibrant yellow.
Chemical techniques, from profiling to identification, will be refined by two-dimensional approaches and
new analyzes with more precise chromatographic methods for future articles.
The detection of a substance in mass spectrometry opens up research possibilities

in toxicity and preservation. This study contributes as a small portion in the literature
on the species Attalea maripa.

Petroleum (or crude oil) is a natural mixture with high chemical complexity, whose consumption is linked to the development of the economy in modern society. It is known that the industrial processes of extraction, transport, and use of petroleum inevitably result in spills to the environment associated. In this scientific document, we describe two studies conducted with the purpose of developing and applying strategies related to environmental forensic petroleum chemistry. In Study I, we investigated the changes in the chemical composition of a crude oil during spill simulations in terrestrial and aquatic environments over time (from 1h to 120 hours), in an environmental forensic chemistry approach, using Fourier Transform Mass Spectrometry (FT-MS) data analysis using Atmospheric Pressure Photoionization (APPI(+)) and Electrospray Ionization (ESI(-)) sources. Chemical changes were found in the course of time up to 120h for molecular formulas of the constituent compounds of the petroleum under study, in terms of differences in abundances and distribution of Double Bond Equivalent (DBE) versus carbon number, referring for example to N, O and O₂ classes, both in simulations of oil spills in terrestrial and aquatic environments. The data showed effectiveness in the application of the spill simulation chamber, whose use promoted relevant chemical modifications in the composition of the oil under study during the simulated spill process. In Study II, gas chromatography/sequence mass spectrometry (GC-MS/MS) analyses of twelve samples collected at the time of the oil spill that hit the Pernambuco coastal coast in 2019 were performed, with the purposes of chemically characterizing in terms of the biomarkers and performing an investigative approach to identify the possibility that additional unreported events may have contributed to the appearance of the oil material on the state's beaches. The absence of the biomarkers 18α(H)-oleanane and 18β(H)-oleanane isomers in the study of the chromatographic profiles of sample 10 as well as the results obtained for the multivariate statistical analyses of the data, indicated that it has chemical dissimilarities compared to the others, characterizing it as originating from an unknown source distinct from the source originating from the other eleven samples, which have similar characteristics among themselves.

Most of the commercialized drugs mimic the natural products found in different types of living organisms. Among these sources of natural products, plants stand out, since they act as “true generating factories” of chemical substances. Natural products and their derivatives have interesting characteristics such as high chemical diversity and biochemical specificity. Thus, this work consisted of the synthesis of bioactive compounds derived from D-glucose in order to evaluate their biological activities. The synthetic strategy adopted consisted of transforming D-glucose into 3,4,6-tri-O-acetyl-D-glucal, which was sequentially submitted to a Glycosylation, Hydrolysis, Oxidation and Allylation reaction. Additionally, this work was structured in three chapters aiming at a better understanding of the results. Chapter 1 discusses the application of 3,4,6-tri-O-acetyl-D-glycal as a building block in the synthesis of natural products and/or biologically active compounds using the Web of Science journal search platform. Chapter 2 describes the synthesis of 3,4,6-tri-O-acetyl-D-glucal, which was obtained in 94% yield and subjected to Ferrier rearrangement with (-)-menthol leading to the formation of O-glycoside in 90% yield. This O-glycoside containing menthol as aglycone was hydrolyzed, leading to the desired compound in 89% yield, then it was subjected to an oxidation reaction using manganese oxide, leading to the enuloside in 76% yield. In addition, an in sílico study was carried out on these carbohydrates derived from (-)-menthol, which showed good patterns of absorption and pharmacokinetics linked to good toxicological characteristics, especially enoloside (6). Based on this study, enuloside (6) underwent antifungal and antiproliferative evaluation. The in vitro study of enuloside (6) indicated promising results for different strains of pathogenic fungi and some tumor cell lines, but further complementary studies are needed. Chapter 3, describes the study of the allylation reaction of different enulosides (6a-d), which were obtained with yields ranging from 70 to 77%. The compounds (7a-d) showed in vitro activity against different bacteria and fungi, however, they showed a cell growth of tumor cells lower than IC% ≥ 70%, which makes the determination of IC50 unfeasible. In short, these results encourage the development of more detailed studies involving synthetic processes and biological evaluation of D-glucose derivatives.

In this work, the compound levan-boron was synthesized as a new candidate for boron neutron capture therapy. The compound was characterized by spectroscopy in the infrared region showing bands in the regions of 1349 cm^-1 (vB-O-C) and 1128 cm^-1 (vBO4), electronic absorption spectroscopy, and nuclear magnetic resonance of ¹H, ¹³C and ¹¹B. After confirmation of its chemical structure, levan-boron solutions were irradiated with a thermal neutron beam in a reactor containing sources of americium-beryllium (AmBe) for periods of 19, 27 and 30 days, then, emission spectrometry analyzes were carried out (ICP-OES) to determine boron concentrations after ¹⁰B(n,α) ⁷Li nuclear reaction and observe ¹⁰B→⁷Li conversion rates. Cytotoxicity tests were carried out against Vero and MCF-7 cell lines and acute toxicity (OECD 423 Protocol). The results of these tests showed a percentage of cell viability between 70- 88% and 72-83%, respectively. The boron compound presented toxicological classification in category 5 in acute toxicity, which is very promising since it can proceed to irradiation tests in tumor cells and in vivo using animal experimentation.

In this work, the Eu(III) and Gd(III) complexes with ligands containing carboxylate groups and thiophene ring were synthesized, characterized, and evaluated spectroscopic properties. The ligand chosen for the present study was sodium (E)-3-(thiophen-3-yl) acrylate, coded as ATAna, and the complexes coded as Ln-ATA-x:1, showed a ligand:ion ratio, being Ln= Eu/Gd trivalent, of x= 3 or 4. The structural characterization took place by infrared (IR); electronic absorption (UV) and luminescence spectroscopy, besides thermogravimetry (TG); scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found the formation of ATANa by missing signal of OH band from the original acid, after its deprotonation. In Eu(III) and Gd(III) complexes was observed asymmetrical (OCO-)as and symmetrical (OCO-)s peaks, besides low values of ∆ν(COO-), obtained by subtraction of (OCO-)as with (OCO-)s, including a bidentate coordination mode. The micrographs indicated that Eu(III) complexes were in stems form while Gd(III) were clusters. The diffractograms also pointed similarities between Eu(III) analogous compounds, but the same was not seen for Gd(III) structures. The excitation spectra of Eu-ATA-3:1 e Eu-ATA-4:1 showed maximum in 317 e 333 nm, associated to transitions (ligand region). The maximum of emission in 613 nm, related to transition 5D0 7F2 of Eu(III) was noted on the two compounds. The intensity parameter Ω2 revealed a strong ionic character and Ω4 suggests stiffness around the ion. Quantum efficiency and yield had low values due to high values of Anrad facing Arad. It is believed that had retrotransference of energy because triplet levels were next to 5D0 level. Structural models were proposed based on carboxylates complexes from literature. The triplets and singlets energies obtained by (Time-Dependent Density Functional Theory – TD-DFT) were close to experimental in model 2, as well as intensity parameters, timelife and quantic yield. An energy diagram were proposed to explain the values of experimental quantic yield obtained.

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Agricultural crops constantly suffer damage caused by pest insects, the lepidopterans, in turn, have caused substantial losses to producers. Plutella xylostella is the most important harmful species to the agricultural development of Brassicas, having as main control mechanism the use of chemical insecticides, which have shown resistance development, besides soil contamination and toxicity on non-target organisms. The present work aims to investigate the insecticidal potential of the essential oils from the leaves of different species of Eugenia, on the moth of crucifers, besides reporting their antioxidant action and chemical composition. The oils from Eugenias, showed yields ranging from 0.05% to 0.82%, besides being characterized with a high profile of sesquiterpenes. The caryophyllene oxide (25.20%) took the majority position in E. dysenterica oil, while the terpenoid longipinanol (15.01%) in E. klotzschiana, as well as spatulenol (12.71%) for E. langsdorffii was the main constituent, the oxygenated sesquiterpene curzerene (37.52%) was revealed for E. uniflora, while E-caryophyllene (51.39%) for E. uvalha. All EOs showed lower antioxidant action than controls by DPPH and ABTS method, which showed low free radical scavenging capacity. The results obtained in the larval toxicity bioassay showed, for E. uniflora leaf oil, a mean lethal concentration of 1.88 μL/mL, which showed higher lethal potential than the commercial products Azamax® (LC50 = 5.04 μL/mL) and Decis® (LC50 = 9.24 μL/mL). The other Eugenia oils showed higher values in this test. On the egg stage of P. xylostella, the treatments used proved to be more toxic, pitangueira (LC50 = 0.02 μL/mL) reaffirmed its higher lethality while E. dysenterica (LC50 = 1.28 μL/mL) and Azamax® (LC50 = 1.07 μL/mL) did not differ statistically. In the analysis of the feeding deterrent effect, E. klotzschiana showed an attractive effect, while cagaita (DA50 = 0.15 μL/mL), pitanga (DA50 = 0.13 μL/mL) and uvaia (DA50 = 0.15 μL/mL) reduced feeding by 50%, but did not differ statistically.

Leishmaniasis is included in the group of neglected tropical diseases (NTDs), and is a group of diseases caused by intracellular protozoa of the genus Leishmania. In view of the severity of the disease and the problems presented by the current drug therapy of this neglected disease, in recent years considerable attention has been paid to secondary metabolites in an attempt to search for new antileishmanial drugs. Numerous studies have been carried out to deepen the knowledge of the biological activity of flavonoids, some of them being reported as antiparasitic, anti-inflammatory and antiviral activities. The present work aims to characterize the flavonoid prototype 37DMK, through a semi-synthetic route using naringenin (2) as starting material through methylation reactions in which they present yields in the range of 70% and easy reproduction, oxidation using I2 and pyridine with 65% yield, protection with benzyl bromide obtaining 65% yield, epoxidation still in the test phase using oxone and future reduction reaction using H2/Pd to remove the protecting groups. In addition to 37DMK, the by-products will also be tested against leishmaniasis in collaboration with Professor Magna Suzana from UFAL. All molecules were characterized by the usual methods in the literature and available in the research group, such as melting point and NMR.

The electro-oxidation of 5-methyl-cytosine (5-mCyt) and 7-methyl-guanine (7-mGua) in aqueous support electrolytes were investigated at carbon electrodes, glassy carbon electrode (GCE) and boron-doped diamond electrode (BDDE), using electrochemical techniques, cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS), as well as compared with the anodic behaviour of other similar bases. The redox properties of methylated bases (5-mCyt and 7-mGua) were also explored to develop electroanalytical methods for detection and quantification of DNA methylation. The electrochemical results indicated that 5-mCyt is more reactive towards Cyt, since its anodic process occurs in the methyl group, at more negative potential values (~ 150 mV), with the removal of one electron and one proton generating intermediate radicals that react with water to form hydroxylated products, such as 5-hydroxy-mCyt, and/or dimerize. Regarding 7-mGua, the results showed that its electro-oxidation mechanism occurs, similarly to Gua, on carbon at the C8 position with the removal of one electron and one proton, forming a highly reactive intermediate radical that can dimerize and/or react with water, producing 8-hydroxy-7-mGua, which can then be electro-oxidized to form an electroactive product in an acidic medium, 8-oxo-7-mGua. Furthermore, the results indicated that, unlike Cyt, the methyl group attached to N7 is not electroactive, but hinders the electro-oxidation of 7-mGua since it occurs at more positive potential values (~ 200 mV) in relation to Gua. The electro-oxidation mechanisms of 5-mCyt and 7-mGua have been proposed. Using DPV, experimental conditions, such as working electrode, electrode size, composition of the supporting electrolyte, pH and influence of possible interferents (Gua, adenine, thymine and cytosine), were investigated for detection and quantification of 5-mCyt and 7-mGua, with low detection limits. Under the best conditions, the proposed DPV method, with a 3.0 mm diameter GCE anodically pretreated, provided a linear analytical curve for 5-mCyt in phosphate buffer solution (pH = 7.0) in the concentration range of 3 at 15 µmol L−1, with a limit of detection (LOD) of 0.11 µmol L−1 and high correlation coefficient (r = 0.997). A DPV method with GCE (1.6 mm) was proposed for the determination of 7-mGua with LOD of 4.2 µmol L-1 and r = 0.989 at pH = 4.5 and with LOD of 3.8 µmol L- 1 and r = 0.995 at pH = 7.0. The detection and quantification of 7-mGua in the presence of interferents, such as Gua, Ade and Thy, was also performed satisfactorily in acetate (pH = 4.5) and phosphate (pH = 7.0) buffer. New simple and sensitive electroanalytical methods, using anodically pretreated GCEs, for the quantification of DNA methylation are then presented and can be applied to real samples of hydrolyzed DNA.

The Pt2+ coordination compounds have an application in the therapy of several types
of cancer, however they having severe side effects. In order to reduce the side effects,
it was proposed the synthesis and characterization of three new Pt2+ complexes
containing cysteamine as a ligand, in addition to an electrochemical study of
commercial complexes such as cisplatin, nedaplatin, oxaliplatin and carboplatin, which
were synthesized to reduce costs. The platinum residues from the laboratory were
treated to form potassium hexachloroplatinate - K2[PtCl6], which was reduced under
mild conditions to form K2[PtCl4], obtaining excellent yields >90%. In the synthesis of
organic salts, equimolar proportions of acids, sodium hydroxide and nitrate and silver
were used to form insoluble silver salts. Platinum precursors were synthesized by
adding excess KI to K2[PtCl4] to form K2[PtI4] in situ and then treated with ammonium
hydroxide and DACH ligand to provide the species cis-[Pt(NH3)2I2].and [Pt(DACH)I2]
with yields of 89.95 and 95.58%. With the silver glycolate and oxalate salts and the
platinum precursors in hand, the synthesis of cisplatin, nedaplatin and oxaliplatin was
carried out to carry out the comparative electrochemical study. In the synthesis of the
new complexes, K2[PtCl4] was reacted with cysteamine to form an intermediate
K[Pt(cysteamine)Cl2] to which Clions were replaced by glycolate, oxalate and
glycinate ligands, providing the K[Pt(cysteamine)(glycolate)],
K[Pt(cysteamine)(oxalate)] and K[Pt(cysteamine)(glycinate)] complexes with good
yields for the first (87.00%) and the third (75.98%) in which the success of the synthesis
was observed through FTIR characterization, electronic absorption spectroscopy,
thermogravimetric analysis and 1H, 13C and HSQC NMR. The voltammetric study of
the commercial compounds showed an increasing order K2[PtCl4] ~ K2[PtCl6] ~
cisplatin < nedaplatin < oxaliplatin < carboplatin, indicating that bidentate ligands
containing oxygen may be more efficient in electrochemical stability. The compounds
K[Pt(cysteamine)(glycolate)] and K[Pt(cysteamine)(glycinate)] showed low cellular
viability (>20%) in the tested MCF-7 strain, indicating promising results comparable or
superior to cisplatin, which justifies the performance of new studies in different strains
and also carrying out the in vivo study.

Brazil is the third largest fruit producer in the world, with a production of over
45 million tons in 2019, most of this production is consumed by the Brazilian
population, exporting just over 35% of its production. The high production of
agribusiness generates large amounts of waste, producing up to 20.3 million tons of
this byproduct, leaving Brazil among the 10 countries that waste most food in the
world, seeds are considered as one of these waste products coming from the
processing industries of fruit / vegetable, this type of residue could be applied in
various areas such as food, cosmetics and pharmaceuticals adding more value to
this residue In the search for the development of new products of natural origin the
antimicrobial properties against fungi and bacteria, the fixed oils of the species
seeds were evaluated Annona squamosa (pinha), Annona Muricata (graviola),
Annona Atemoya (atemoya), Carica papaya L. (mamão), Cucumis melo (melão),
Cucurbita moschata (abóbora), Citrus reticulata (tangerina), Eugenia uniflora
(pitanga), Malpighia emarginata (acerola), Citrullus lanatus (melancia) which were
chemically characterized by GC-MS, subsequently the percentages of oleic and
linoleic acid were compared with the results obtained by 1 H NMR, where their major
compounds were palmitic, stereatic, oleic and linoleic fatty acids. The
physicochemical characterization was performed by bench protocol according to
Instituto Adolfo Lutz and by 1 H NMR integrals, several quality standards were
selected by 1 H NMR spectroscopy such as: saponification index, iodine and acidity,
such as well the average molecular triacylglycerol weight, total satured fatty acid,
degree of unsaturation (linolenic and oleic acids) and the ratio between olefinic and
aliphatic hydrogens. The antimicrobial inhibitory effects of these oils on
microorganisms were also tested: S.aures, P.aeruginosa, K. pneumoniae, E.
faecalis, C. utilis and M. gypseum. The applied technique was the evaluation of the
Minimum Inhibitory Concentration (MIC). Results of antimicrobial activity ranged
from weak to strong, where the best antimicrobial potential was E. uniflora indicating
activity for all microorganisms, the highest E. uniflora activity was for S.aures, K.
pneumoniae and E. faecalis indicating MIC equal to 39 μg.mL -1 . M. emarginata seed
oil was also active against all microorganisms with MIC ranging from 625 to 1250
μg.mL -1 .

The 1,2,4-oxadiazoles are heterocyclics that have numerous pharmacological activities such as anti-inflammatory, larvicidal and fungicidal, among others. Undoubtedly, the biological properties conferred on 3,5-disubstituted 1,2,4-oxadiazoles added to the intermediation of the 2,3-unsaturated glycoside make the 2,3-unsaturated O and S-glycosides having an aglycone unit 1,2,4 -oxadiazoles in a potential source of new drugs. The present work describes the synthesis and characterization of new 1,2,4-oxadiazoles-3,5-disubistuted monos, and new 2,3-unsaturated O and S-glycosides through ring-linked Ferrier Rearrangement 1,2, 4-oxadiazole in the aglyconic part. A priori, the synthesis of the starting compounds was performed: 51a-i (amidoximes) and isopropyl 3-mercaptopropionate. The synthesis of arylamidoximes 51a-i was carried out starting from 49a-i (nitriles) with hydroxalamine hydrochloride and sodium carbonate as base. Products 55a-i were obtained in moderate to good yields (30% - 97%).Isopropyl 3-mercaptopropionate was obtained by Fischer's esterification reaction of propionic 3-mercapto acid, with isopropyl alcohol employing sulfuric acid as catalyst, which was obtained with a satisfactory yield of 75%. On the other hand, the synthesis of 1,2,4-oxadiazole 7a-d was developed, lasting 10 minutes, using microwave irradiation providing the compounds in moderate yields. The structures of 55a-i were characterized by infrared and nuclear magnetic resonance techniques (1H and 13C NMR). The cytotoxic evaluation was performed against Artemia salina, where it was found that the mortality percentage varied from 75-100% in all concentrations. As for antimicrobial activity, it was found that the compound 55c was the most active against the bacteria Staphylococcus aureus and Enterococcus faecalis (Gram-positive). All compounds demonstrated a good ability to inhibit the growth of Escherichia coli (Gram-negative) bacteria.

The vanadium (IV) complexes have demonstrated antidiabetic activity, due to the ability to decrease blood glucose levels, increase insulin sensitivity in adipose and skeletal muscle tissues, besides having antioxidant effects, decreasing ROS and hypolipidemic effects, reducing the levels of triglycerides and total cholesterol. This work aims to develop a new oxovanadium (IV) complex using as ligand the diaminoalcohol biocompatibilized with the exopolysaccharide matrix Levan, obtained from the microorganism Zymomonas mobilis strain ZAG-12. The oxovanadium (IV) complex with the diaminoalcohol, abbreviated as VHEEDA, was synthesized and characterized by electronic and infrared absorption spectroscopy, 1H, 13C and 51V nuclear magnetic resonance, EPR and thermogravimetric analysis. The results demonstrated the reproducibility in obtaining the levan and the complex. The VHEEDA complex showed no nephrotoxicity and hepatotoxicity in the acute toxicity assay in mice, being classified as category 4 according to OECD protocol 423. In dexamethasone-induced insulin resistance activity, VHEEDA (95%) + Levana (5%) compositions with doses of 50 mg/Kg and 25 mg/Kg, showed a 50% reduction in blood glucose, triglycerides and TyG after 7 days of treatment, with no significant difference with the normoglycemic group (p>0. 05) Therefore, the composition of vanadium complex biocompatibilized with levan demonstrated antidiabetic activity by attenuating glucocorticoid-induced insulin resistance.

Gas Chromatography Coupled to Mass Spectrometry (GC-MS) has been historically used for the identification of classical oil biomarkers, getting geochemical properties, including the degree of thermal evolution that indicates the thermal maturity as a function of the formation temperature of oil reservoirs. However, GC-MS methods require a large data analysis and processing time. A recent and fast technique, named as Fourier Transform Ultra-High Resolution Mass Spectrometry (FT-MS) has demonstrated a high potential for crude oils chemical characterization. The study aims to investigate a new potential oil biomarker using FT-MS analyses to obtain a thermal evolution compound detected in a simpler and faster way than those by classical methods employing GC-MS. A total of 14 standard compounds that are typically present in crude oils (classes of thiophenes, pyridinols, carboxylic acids, alcohols, ketones and hydrocarbons) were investigated and analyzed by FT-MS using electrospray ionization (ESI). Standard compounds were also subjected to analytical micropyrolysis (Py) at temperatures up to 500 ºC, aiming to simulate thermal processes. Furthermore, as proof of concept, four crude oils samples with different degrees of thermal evolution measured by GC-MS were also analyzed by FT-MS. Among all the standard compounds analyzed, the Py data of 2,3-dimethyl-pyridin-4-ol obtained by FT-MS in the ESI(-) mode (m/z 122.06021, molecular formula C7H8ON) showed the formation of ions with m/z and molecular formulas: 122.06021 (C7H8ON); 241.09818 (C14H13O2N2); 348.17201 (C21H22O2N3) and 453.23002 (C28H29O2N4), which suggested that thermal processing leads to the formation of new compounds. Comparing these data with the MS of the four crude oils obtained by ESI(-) FT-MS, it was determined the presence of the same ions, indicating that they are compounds formed in the process of thermal evolution of oils. Therefore, linear correlations were found between the abundances of ions with m/z 122.06015 and 241.09807 (referring to 2,3-dimethyl-pyridin-4-ol and its Py product) and the diagnostic ratios for thermal evolution using classical biomarkers obtained by GC-MS. Thus, we conclude that 2,3-dimethyl-pyridin-4-ol proved to be a potential biomarker to determine the thermal evolution of crude oils, and could be used as an alternative for geochemical studies.

An electrochemical study of 3-nitro-tyrosine (3-NO2-Tyr), in aqueous medium, was performed on different electrochemical substrates, glassy carbon electrode (GCE), platinum and gold electrode, using voltammetric techniques, such as cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS), to investigate its oxidation mechanism, as well as its reactivity / toxicity to the double-strands DNA molecule (dsDNA). para-Tyrosine electro-oxidation in aqueous media was also investigated and compared with 3-NO2-Tyr. Potentialities of 3-NO2-Tyr oxidation properties for electroanalytical applications were also studied. The electrochemical results, in general, showed that 3-NO2-Tyr undergoes electro-oxidation in aqueous medium in a single irreversible pH-dependent step, losing one electron and one proton in the phenolic group and forming non-electroactive products, that are adsorbed strongly on all used electrodes. In addition, the phenolic group present in the 3-NO2-Tyr structure was found to be more difficult to oxidize (~ 170 mV) when compared to its electro-oxidation in the para-tyrosine molecule, possibly due to the influence of the nitro group. an electron withdrawing group. The mass transport of 3-NO2-Tyr to the electrode surface was investigated at platinum electrode and it was established that it is predominantly diffusion controlled. Electroanalytical methods for detection and quantification of 3-NO2-Tyr were proposed at GCE, gold and platinum electrode, the detection limits (LOD) and quantification (LOQ) of these methods were calculated and compared. At GCE the LOD was 0.17 μmol L-1, in the platinum electrode was 6,81 μmol L-1, while in the gold electrode was 7,33 μmol L-1, demonstrating a better sensitivity for detection and quantification of 3-NO2-Tyr. at GCE. Finally, the DPV and gel electrophoresis results clearly demonstrated a 3-NO2-Tyr interaction with dsDNA molecule in physiological medium (pH = 7.0), since the DPV results over incubation time of 3-NO2-Tyr with DNA, detected a significant decrease or the complete disappearance of the anodic peak associated with 3-NO2-Tyr oxidation, at E = 0.70 V, while electrophoresis results detected a very significant decrease in the ethidium bromide fluorescence. Thus, it was established the interaction of 3-NO2-Tyr possibly via its intercalation in the DNA double helix and with formation of a stable 3-NO2-Tyr-dsDNA complex, hindering the oxidation of 3-NO2-Tyr on the GCE, as well as the intercalation of the fluorescent biomarker, ethidium bromide, on the dsDNA.

NOVA GERAÇÃO DE SISTEMAS BI E TRINUCLEARES LUMINESCENTES

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In this work a series of novel lapachol adducts with aliphatic primary amines were synthesized. These amines included 2-aminoethanol, 3-amino-1-propanol, 2- methoxy-ethylamine, 3-methoxy-propylamine, n-butylamine and glycine. All reactions were performed under ambient temperature and without solvents. The newly products with unique structures were characterized by IR and UV spectroscopy and 1H and 13C NMR with bi-dimensional techniques. A possible mechanism was proposed based on the ability of the quinones to react as radical species, where a initially formed imine act as a nucleophile with a second molecule of lapachol, and this primary adduct results in observed products under the oxidant conditions used in reaction. To test this hypothesis the reaction was conducted in inert atmosphere or in the presence of an antioxidant (BHT), and the reaction mixture behaves differently, as expected.