Bioactive Secondary Metabolites from Tecomella undulata

Chromatographic purification of the methanolic extract of Tecomella undulata yielded a new flavonoid glycoside; kaempferol-3-O-beta-D-[3"',4"'di-p-E-coumaroyl-alpha-L-rhamnosyl(1 -> 6)] galactoside (1), two new megastigmanes; (6R 7Z)-9,10-dihydroxy-4,7-megastigmadien-3-one (2) and (6E)-9,10-dihydroxy-4,6-megastigmadien-3-one (3) along with three known compounds; (6R 9S)-9,10-dihydroxy-4-megastigmaen-3-one (4) quercetin-3-galactoside (5) and 3'-dimethoxy-5,6,4'-trihydroxyflavon (6). All the isolates 1-6 were characterized by the combination of 1D (H-1, C-13), 2D (COSY, HSQC and HMBC) NMR data and high resolution mass spectrometric analysis. In antibacterial assay, compound 1 showed moderate inhibitory activity against Escherichia coli and Salmonalla typhi.