Cytotoxic monacolin analogs from Monascus purpureus-fermented rice.

Two new monacolin analogs, monacolins O (1) and P (2), along with three known analogs, have been isolated from the ethanolic extract of Monascus purpureus-fermented rice. Their structures and absolute configurations were elucidated by spectroscopic methods, especially 2D NMR and CD spectral analyses as well as chemical method. Both 1 and 2 were tested against five tumor cell lines, and compound 1 exhibited selective cytotoxic activity against A2780 and A549 cell lines, with IC50 values of 3.7 and 8.0 μM, respectively.