O-glicosídeos 2,3-insaturados e azidoglicosídeo : síntese, caracterização estrutural e atividade biológica

Abstract

O-glycosides are easily available chiral intermediates in the synthesis of biologically active compounds such as glycopeptide building blocks, oligosaccharides, and modified carbohydrates. This work describes the syntheses, characterization and cytotoxic activity in vitro de 2,3-unsaturated O-glycosides and azide glycosides. The reaction of alcohols 2a-i with 3,4,6-tri-O-acetylglucal 1, carried out in presence of catalytic amount of p-tolylsulfonicacid mediated by ultrasound irradiation, afforded the corresponding 2,3-unsaturated glucopyranosides3a-i. In all cases the compounds were obtained as a mixture of α-β-anomers, where there was a predominance of anomer α. Moreover, the conventional methodology used to obtain the 2,3-unsaturated O-glycosides 4a-e. The O-glycosides were subjected to reactions of basic hydrolysis and allylic oxidation. Addition of azide ion to alkyl 2,3-dideoxy-2-enopiranosid-4-ulose (6a-e) provided compound 7a-e, which upon reduction with sodium borohydrate furnishedazide glycosides 8a-e in good yields. The structures of the compounds obtained were elucidated by conventional spectroscopic techniques: Infrared and Magnetic Nuclear Resonance 1H and 13C. The compounds 5a-e and 8a-e were tested against three human cell lines where only of compounds 5a, 5c, 3d, 8b e 8c exhibited good antiproliferative activity against HL-60, MCF-7e NCI-H292 cancer cell lines with excellent inhibition values.