Comparative Chemical Profiling and Monacolins Quantification in Red Yeast Rice Dietary Supplements by 1H-NMR and UHPLC-DAD-MS

The study validated the 1H-NMR method for determining monacolin content in 31 Red Yeast Rice (RYR) dietary supplements, comparing it with the established UHPLC-DAD-MS method. It found significant variability in monacolin content, with monacolin K (MK) being the predominant compound. Only 50% of the products contained the declared monacolin amounts, highlighting discrepancies between labeled and actual content. The study emphasized the need for standardized regulation and precise quantification of monacolins to ensure the efficacy and safety of RYR supplements in cholesterol regulation. The 1H-NMR method was deemed effective for rapid determination of total monacolin content, though it had limitations in specificity compared to UHPLC-DAD-MS.