Bauhinoxepins A and B: New Antimycobacterial Dibenzo[<i>b</i>,<i>f</i>]oxepins from <i>Bauhinia saccocalyx</i>

Abstract

Abstract Two new antimycobacterial dibenzo[ b , f ]oxepins, bauhinoxepins A (=3,3,5‐trimethylbenzo[ b ]pyrano[ g ][1]benzoxepin‐6,11‐diol; 1 ) and B (=6‐methoxy‐7‐methyl‐2‐(3‐methylbut‐2‐enyl)dibenzo[ b , f ]oxepine‐1,8‐diol; 2 ), were isolated from the roots of Bauhinia saccocalyx , and their structures were elucidated by analysis of spectroscopic data. Bauhinoxepins A and B exhibited antimycobacterial activities with respective minimum‐inhibitory concentrations ( MIC ) of 6.25 and 12.5 μg/ml. They were inactive (at 20 μg/ml) against the malarial parasite, and also inactive (at 20 μg/ml) towards the Vero, KB, and BC cell lines.