Aromatic polyketides from a sponge-derived fungus Metarhizium anisopliae mxh-99 and their antitubercular activities

In our screening for antitubercular agents, five naphtho-gamma-pyrones including two new naphtho-gamma-pyrones glycosides, indigotides G and H (1 and 2), and two diphenyl ethers were isolated from the extract of a sponge-derived fungus Metarhizium anisopliae mxh-99. Their structures were established on the basis of chemical and spectroscopic evidence. The antitubercular activities of all the compounds were evaluated against Mycobacterium phlei. The known isochaetochromin B-2 (6) and ustilaginoidin D (7) exhibited the highest activity with MICs 50.0 mu g/mL.