Constituents Isolated from the Fungus Monascus sp.

Further study on a 95% EtOH extract of the red mold rice fermented with the mutant of the fungus Monascus sp. led to the isolation of one new natural pyranoid derivative, namely monascuslactone (1), together with three known compounds. The structure of the new compound was determined as (4S*,6S*)-4-hydroxy-4,6-dimethyltetrahydro-2H-pyran-2-one. The known compounds were identified as monascin (2), ankaflavin (3), and methyl N-methyl anthranylate (4). 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.