CHEMICAL CONSTITUENTS ISOLATED FROM THE FUNGUS Monascus sp.

Further study of a 95% EtOH extract of red mold rice fermented with the yellow mutant of the fungus Monascus sp. led to the isolation of one new chroman derivative, namely monascuskaochroman (1), together with nine known compounds. The structure of the new compound was determined as 4-(1-hydroxy-1-methylethyl)-chroman-4-carboxylic acid amide. The known compounds were identified as monascin (2), ankaflavin (3), (3R, 6R,7E)-(+)-3-hydroxy-4,7-megstigmadien-9-one (4), vanillin (5), syringic acid (6), 3,4,5-trimethoxybenzoic acid (7), trans-methyl p-coumarate (8), ferulic acid (9), and methyl N-methyl anthranylate (10). This is the first report of a naturally occurring chroman skeleton isolated from Monascus species. Compounds 4-10 were isolated from this species for the first time. Their structures were elucidated by 1D and 2D NMR spectroscopy together with HR-ESI-MS analysis, and comparison of the spectroscopic data with those reported for structurally related compounds.