Secondary metabolites and antimycobacterial activities from the roots of Ficus nervosa

Bioassay-guided fractionation of the active AcOEt-soluble layer led to the isolation of two new pyranocoumarins, 3-hydroxyxanthyletin (1) and 3-methoxyxanthyletin (2), along with 22 known compounds including four simple Coumarins, i.e., xanthyletin (3), umbelliferone (4), scopoletin (5), and (+)-(S)-marmesin (6); nine Flavonoids, i.e., carpachromene (7), parvisoflavone B (8), alpinumisoflavone (9) genistein (10), 2'-hydroxygenistein (11), prunetin (12), cajanin (13), apigenin (14), and (2S)-naringenin (15); three benzenoids, i.e., 4-hydroxybenzaldehyde (16), vanillin (17), and (S)-lasiodiplodin (18); five Steroids, i.e., ergosterol peroxide (19), a mixture of 6beta-hydroxystigmast-4-en-3-one (20) and 6beta-hydroxystigmasta-4,22-dien-3-one (21), and a mixture of beta-sitosterol (22) and stigmasterol (23); and one triterpenoid, i.e., oleanolic acid (24) from the roots of Ficus nervosa. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR as well as MS analyses. Among these isolates, 3-hydroxyxanthyletin (1), genistein (10), prunetin (12), and (2S)-naringenin (15) showed antimycobacterial activities against Mycobacterium tuberculosis H(37)R(V) in vitro with MIC values of 16, 35, 30, and < or =2.8 microg/ml, respectively.