Cytotoxic constituents from the fungus Daldinia concentrica (Xylariaceae).

Phytochemical study on the methanol extract of the fruit bodies of Vietnamese fungus Daldinia concentrica has led to the isolation and structural elucidation of three cytotoxic constituents, 6,8-dihydroxy-3-methyl-3,4-dihydroisocoumarin (1), (22R)-hydroxylanosta-7,9(11),24-trien-3-one (2) and ergosterol (3). Their structures were elucidated by 2D-NMR and FT-ICR-MS. All the three compounds showed moderate cytotoxicity against four cancer cells, KB (a human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma) and HepG2 (hepatocellular carcinoma). In addition, the isocoumarin (1) inhibited the growth of Staphylococcus aureus with the IC50 value of 87.81 µg mL(-1).