Secondary Metabolites from the Fungus Monascus purpureus and Evaluation of Their Cytotoxic Activity

Investigation of the 95% EtOH extract of red yeast rice fermented with the fungus Monascus purpureus BCRC 31615 has led to the isolation and structure elucidation of four new compounds, including one new azaphilone analog, monascuspurpurone (1), a new isocoumarin, monaschromone (2), a new furan‐3‐one derivative, 2‐dodecyl‐5‐(2‐methoxyethyl)‐2‐methylfuran‐3(2H)‐one (3), and a new alkaloid, methyl 4‐[(E)‐2‐acetyl‐4‐oxoundec‐1‐enyl]‐6‐propylnicotinate (4), together with seven known compounds. The structures of all isolates were elucidated on the basis of extensive spectroscopic analyses and comparison with literature data. Compounds 1–4 were tested for their cytotoxicity against the MCF‐7, NCI‐H460, and SF‐268 cell lines using the MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) assay. Among them, compounds 1 and 4 were found to have moderate cytotoxic effects against these three cell lines in vitro.