Isolation and structure elucidation of two new cytotoxic metabolites from red yeast rice.

Ferse I, Langlitz M, Kleigrewe K, Rzeppa S, Lenczyk M, Harrer H, Cramer B, Humpf HU

Abstract

In this study, 10 already described secondary metabolites and 2 unknown metabolites were identified in an extract of Monascus purpureus by high-performance liquid chromatography-diode array detection. The unknown metabolites were isolated and their chemical structures were elucidated. The new metabolites possess the molecular formulas C(21)H(27)NO(4) and C(23)H(31)NO(4). They were named monascopyridines E and F due to their pyridine backbone. The cytotoxicity of the new compounds was studied using immortalised human kidney epithelial cells displaying IC(50) values in the micromolar range.