A novel cyclodepsipeptide, cordycommunin (1), and two dihydroisocoumarins (2 and 3) were isolated from the insect pathogenic fungus Ophiocordyceps communis BCC 16475. The absolute configurations of the amino acid residues of 1 were addressed by application of Marfey's method. Cordycommunin (1) showed growth inhibition of Mycobacterium tuberculosis H37Ra with an MIC value of 15 microM. This compound also exhibited weak cytotoxicity to KB cells with an IC50 of 45 microM, while it was inactive against BC, NCI-H187, and Vero cell lines at a concentration of 88 microM (50 microg/mL).

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Sixteen new lanostane triterpenoids (1-16), together with 26 known compounds (17-42), were isolated from cultures of the basidiomycete Ganoderma sp. BCC 16642. Antitubercular activities of these Ganoderma lanostanoids against Mycobacterium tuberculosis H37Ra were evaluated, and structure-activity relationships are proposed.

In a continuation of our research into antitubercular lanostane triterpenoids from submerged cultures of Ganoderma species, three strains, Ganoderma orbiforme BCC 22325, Ganoderma sp. BCC 60695, and Ganoderma australe BCC 22314, have been investigated. Fourteen new lanostane triterpenoids, together with 35 known compounds, were isolated. Antitubercular activities of these mycelium-associated Ganoderma lanostanoids against Mycobacterium tuberculosis H37Ra were evaluated. Taken together with the assay data of previously isolated compounds, structure-activity relationships of the antitubercular activity are proposed. Most importantly, 3β- and 15α-acetoxy groups were shown to be critical for antimycobacterial activity. The most potent compound was (24E)-3β,15α-diacetoxylanosta-7,9(11),24-trien-26-oic acid (35).

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