Dihydrocucurbitacin B: Semisynthesis of new glicoside derivatives

MACHADO, VANESSA R.; LANG, KAREN L.; DURÁN, FERNANDO J.; CABRERA, GABRIELA M.; PALERMO, JORGE A.; SCHENKEL, ELOIR P.; BERNARDES, LÍLIAN S. C.

QUíMICA NOVA

SOC BRASILEIRA QUIMICA

Año: 2015 vol. 38 p. 37 - 41

0100-4042

In the last ten years, the interest in natural and semi-synthetic cucurbitacin derivatives has increased, primarily due their cytotoxic and anti-tumoral activities. However, the isolation of glycosylated cucurbitacins has been difficult due the presence of β-glucosidase enzyme. With the aim of obtaining new glycosylated derivatives, the glycosylation of dihydrocucurbitacin B under Köenigs-Knorr and imidate reaction conditions was studied. Novel glycoside derivatives 16-(1,2-orthoacetate-3,4,6-tri-O-acetyl-α-D-glucopyranosyl)-dihydrocucurbitacin B (2), 2-O-β-D-2,3,4,6-tetra-O-acetyl-galactopyranosyl dihydrocucurbitacin B (3) and 2-O-β-D-galactopyranosyl dihydrocucurbitacin B (4) were synthesized for the first time in 17% (2 and 3) and 48% (4) yields. 2015, Sociedade Brasileira de Quimica. All rights reserved.