A novel dimeric coumarin analog and antimycobacterial constituents from Fatoua pilosa.

One novel dimeric coumarin analog, fatouapilosin (1), together with 18 known compounds, have been isolated from the whole plants of Fatoua pilosa. The structures of these isolates were elucidated by means of spectroscopic techniques (UV, IR, MS, 1H- and 13C-NMR, DEPT, COSY, NOESY, HSQC, HMBC, and MS analyses). Among the tested compounds 2-14, scopoletin (3), isobavachalcone (12), and (E)-1-[2,4-dihydroxy-3-(3-methylbut-2-enyl)phenyl]-3-(2,2-dimethyl-8-hydroxy-2H-benzopyran-6-yl)prop-2-en-1-one (14) exhibited the strongest antimycobacterial activities against Mycobacterium tuberculosis H(37)Rv, with MIC values of 42, 18, and 30 microg/ml, respectively.