Two new 3-hydroxyisoflavanones, (S)-3,40 ,5-trihydroxy-20 ,7-dimethoxy-30 -prenylisoflavanone (trivial name kenusanone F 7-methyl ether) and (S)-3,5-dihydroxy-20 ,7-dimethoxy-200,200-dimethylpyrano[500,600:30 ,40 ]isoflavanone (trivial name sophoronol-7-methyl ether) along with two known compounds (dalbergin and formononetin) were isolated from the stem bark of Dalbergia melanoxylon. The structures were elucidated using spectroscopic techniques. Kenusanone F 7-methyl ether showed activity against Mycobacterium tuberculosis, whereas both of the new compounds were inactive against the malaria parasite Plasmodium falciparum at 10 mg/ml. Docking studies showed that the new compounds kenusanone F 7-methyl ether and sophoronol-7-methyl ether have high affinity for the M. tuberculosis drug target INHA.