Anti-inflammatory compounds from Monascus pilosus-fermented rice

Investigation of the 95% ethanolic extract of red yeast rice fermented with the pink mutant of the fungus Monascus pilosus BCRC PK-1 led to the isolation of one new pyridine alkaloid, namely (E)-methyl 4-(2-acetyl-4-oxotridec-1-enyl)-6-propylnicotinate (1), together with 9 known compounds (2-10). Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. We also evaluated the inhibitory effects of some isolates on the production of tumor necrosis factor (TNF-α) induced by lipopolysaccharide (LPS). Among the isolates, compounds 1 and 2 inhibited TNF-alpha production in U937 cells in vitro, and the IC50 values are 1.52 and 2.56 μg/ml, respectively.

Graphical abstractInvestigation of the 95% ethanolic extract of red yeast rice fermented with the pink mutant of the fungus Monascus pilosus BCRC PK-1 led to the isolation of one new pyridine alkaloid, namely (E)-methyl 4-(2-acetyl-4-oxotridec-1-enyl)-6-propylnicotinate (1), together with 9 known compounds (2-10). The inhibitory effects of some isolates on the production of tumor necrosis factor (TNF-α) induced by lipopolysaccharide (LPS) were evaluated.Download full-size imageHighlights► Ten compounds were isolated from Monascus pilosus BCRC PK-1. ► Compound 1 was a new pyridine alkaloid derivative. ► Compounds 1 and 2 inhibited TNF-alpha production in U937 cells in vitro.