ABSTRACT
Three glycosides were isolated from Bougainvillea glabra and their structures were determined by extensive use of 1D and 2D NMR spectroscopy ((1)H and (13)C). First compound was identical to momordin IIc (quinoside D) [beta-D-glucopyranosyl 3-O-[beta-D-xylopyranosyl-(1 --> 3)-O-(beta-D-glucopyranosyluronic acid)] oleanolate], second compound was quercetin 3-O-alpha-L-(rhamnopyranosyl)(1 --> 6)-[alpha-L-rhamnopy-ranosyl(1 --> 2)]-beta-D-galactopyranoside and third compound was its derivative quercetin 3-O-alpha-L-(4-caffeoylrhamnopyranosyl)(1 --> 6)-[alpha-L-rhamnopyranosyl (1 --> 2)]-beta-D-galactopyranoside, a new natural product.
Subject(s)
Glycosides/isolation & purification , Nyctaginaceae/chemistry , Glycosides/chemistry , Magnetic Resonance Spectroscopy , StereoisomerismABSTRACT
Fifteen new bidesmosidic triterpenoid saponins (1-15) were isolated from a methanol extract of the leaves of Mimusops laurifolia. Their structures were established using one- and two-dimensional NMR spectroscopy and mass spectrometry and determined to be bidesmosides of protobassic acid (2-4, 11, 12, and 15) and of 16alpha-hydroxyprotobassic acid (1, 5-10, 13, and 14).
