Banca de DEFESA: JONATAS TAVARES DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JONATAS TAVARES DA SILVA
DATE: 26/02/2025
TIME: 18:00
LOCAL: Departamento de Química
TITLE:

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY OF 2,3-UNSATURATED O-GLYCOSIDES CONTAINING TERPENIC UNITS AS AGLYCONE

KEY WORDS:

2,3-unsaturated O-glycosides; Allelic rearrangement; 3,4,6-tri-O-acetyl-D-glycal; Terpenes.

PAGES: 106
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

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.

COMMITTEE MEMBERS:
Presidente - JOAO RUFINO DE FREITAS FILHO
Interno - MARCILIO MARTINS DE MORAES
Externo ao Programa - 3022573 - JUCLEITON JOSE RUFINO DE FREITAS - UFRPE