Unusual aromatic monacolin analogs from red yeast rice with HMG-CoA reductase inhibitory activity

Three new unusual aromatic monacolin analogs, aromonacolin B (1), aromonacolin C (2), aromonacolin D (3), and one known α, β-hydromonacolin Q (4) were isolated and elucidated from a lipid-lowering active fraction in the ethyl acetate extraction of red yeast rice ethanol extract. The structures of these compounds were established through spectroscopic methods and literatures. All compounds showed very strong HMG-CoA reductase inhibitory activity with IC₅₀ values of 0.015 μg/mL, 0.054 μg/mL, 0.089 μg/mL, and 0.47 μg/mL, respectively, and the lipid-lowering activity was about 10 times stronger than that of the positive control drug lovastatin (0.36 μg/mL).