Banca de DEFESA: RAYANE DE OLIVEIRA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAYANE DE OLIVEIRA SILVA
DATE: 27/06/2023
TIME: 08:00
LOCAL: Departamento de Química
TITLE:

RATIONAL PLANNING OF NEW CARBOHYDRATES APPLIED AS ANTINEOPLASTIC, ANTIMICROBIAL AND ANTIVIRAL

KEY WORDS:

Organic Synthesis, Natural Products, O-glycosides, In Silico Study, Biological Activity.

PAGES: 186
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

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.

COMMITTEE MEMBERS:
Presidente - ***.451.424-** - JULIANO CARLO RUFINO DE FREITAS - UFCG
Interno - JOAO RUFINO DE FREITAS FILHO
Interno - MARCILIO MARTINS DE MORAES
Externa à Instituição - GISELLE BARBOSA BEZERRA
Externo à Instituição - SEBASTIÃO MELO