Antibacterial sesquiterpene lactone glucoside from seed pods of Bauhinia retusa.

From the seed pods of Bauhinia retusa, a new eudesmane sesquiterpene glucoside, 1-O-β-D-glucopyranosyl-9β,15-dihydroxy-5α,6βH-eudesma-3-ene-6α,12-olide (1), has been isolated together with three known compounds, 4'-hydroxy-7-methoxy flavane (2), β-sitosterol (3), and stigmasterol (4). The structures of isolated compounds were verified with the help of 1D, 2D NMR, and HR-ESI-MS spectroscopies. Compound 1 showed moderate antibacterial activity against Pseudomonas aeruginosa and Escherichia coli when a disc diffusion method is used.