Glycosides from Bougainvillea glabra

Three glycosides were isolated from Bougainvillea glabra and their structures were determined by extensive use of 1D and 2D NMR spectroscopy (H-1 and C-13). Compound 1 was identical to momordin IIc (quinoside D) [beta-D-glucopyranosyl 3-O-[beta-D-xylopyranosyl-(1 -> 3)-O-(beta-D-glucopyranosyluronic acid)] oleanolate], compound 2 was quercetin 3-O-alpha-L-(rhamnopyranosyl)(1 -> 6)-[alpha-L-rhamnopy-ranosyl(1 -> 2)]-beta-D-galactopyranoside and compound 3 was its derivative quercetin 3-O-alpha-L-(4-caffeoylrhamnopyranosyl)(1 -> 6)-[alpha-L-rhamnopyranosyl (1 -> 2)]-beta-D-galactopyranoside, a new natural product.