Nature's cholesterol-lowering drug: Isolation and structure elucidation of lovastatin from red yeast rice-containing dietary supplements

摘要

Red yeast rice, produced by fermenting the fungus, Monascus purpureus, on rice (Oryza sativa L. gramineae), is commonly used as a dietary supplement. It contains lovastatin, a member of the statin family of compounds, and is licensed for use as a cholesterol-lowering agent. This experiment involves the isolation and structure elucidation of lovastatin from red yeast rice-containing dietary supplements. Isolation of the neutral constituents in red yeast rice can be performed using either ether or ethyl acetate as extracting solvent, and flash column chromatography combined with thin-layer chromatography is used to isolate lovastatin in pure form from the extract. During the course of the experiment, the students isolate lovastatin with an average recovery of 0.31%. IR, MS, and detailed NMR spectroscopic analyses confirm the structure of lovastatin. The experiment can be completed over two, 3-h laboratory sessions and is suitable for students at the third- or fourthyear undergraduate level. Overall the experiment acquaints the student with the techniques required to isolate and complete structure elucidation studies on natural products. This experiment also highlights that dietary supplementsmay contain substances with potent pharmacological actions that are not expected from a cursory inspection of the labeled products.