Hopane-type saponins from Glinus lotoides Linn

Abstract

Seven hopane-type saponins were isolated from the methanol extract of Glinus lotoides. Six of them were identified as novel compounds and designated as lotoideside A [3-O-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl-6 alpha-O-beta-D-xylopyranosyl-22-beta-O-beta-D-glucopyranosyl-16 beta-hydroxy hopane (1)], lotoideside B [3-O-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl-22-beta-O-beta-D-glucopyranosyl-6 alpha,16 beta-dihydroxyhopane (2)], lotoideside C [3-OD-xylopyranosyl-6 alpha-O-beta-D-xylopyranosyl-16 beta-O-beta-D-xylopyranosyl-22 beta-hydroxyhopane (3)], lotoideside D [3-O-beta-D-xylopyranosyl-16 beta-O-alpha-L-arabinopyranosyl-6 alpha,22-beta-dihydroxyhopane (4)], lotoideside E [3-O-beta-D-xylopyranosyl-6 alpha-O-beta-D-xylopyranosyl-16 beta,22-beta-dihydroxyhopane (5)], and lotoideside F [3-O-beta-D-xylopyranosyl-22-beta-O-beta-D-glucopyranosyl-16 beta-hydroxyhopan-6-one (6)]. The known compound succulentoside B (7) was also encountered. Their structures were elucidated on the basis of one-and two-dimensional NMR spectroscopic techniques, ESIMS and chemical evidences.