Two new triterpene glycosides from the seeds of Dimocarpus longan

Two undescribed triterpene glycosides, 3-[(O-alpha-L-rhamnopyranosyl-(1 -> 2)-alpha-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid O-beta-D-xylopyranosyl-(1 -> 2)-O-[beta-D-xylopyranosyl-(1 -> 6)]-beta-D-glucopyranoside (1) and 3-[(O- beta-D-xylopyranosyl-(1 -> 3)-O-alpha-L-rhamnopyranosyl-(1 -> 2)-alpha-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid O- alpha-L-rhamnopyranosyl-(1 -> 2)]-O-[beta-D-xylopyranosyl-(1 -> 6)]-beta-D-glucopyranoside (2), named longanosides A and B, respectively, were isolated from the seeds of Dimocarpus longan Lour. by various chromatography methods. The structures of the isolated compounds were established by interpretation of spectroscopic data (1D and 2D NMR) and mass spectrometry (HR-ESI-MS).