STUDY ON CHOLESTEROL LOWERING COMPOUNDS IN RED YEAST RICE PREPARED FROM THAI GLUTINOUS RICE

Red yeast rice which is a product of solid fermentation was prepared from several kinds of Thai glutinous rice (Oryza sativa L.) cv. Kor Kho 6 (RD6), Kam (Kam) and Sanpatong1 (SPT1). Monascus purpureus CMU001 isolated from available Chinese red yeast rice was used as the fermentation starter. The analysis for the presence and the content of monacolins, the cholesterol lowering compounds, were carried out using high performance liquid chromatography (HPLC). The presence of the monacolins was confirmed by the retention time of the reference compounds and LC-MS. The results were compared to those obtained from the Chinese redyeast rice and Thai non-glutinous rice (Oryza sativa L. cv. Mali105).The chromatograms shows the presence of monacolin K acid form (MKA), compactin (P1) , monacolin M acid form (MMA), monacolin K (MK), monacolin M (MM) and dehydromonacolin K (DMK). A large peak of a compound with the molecular weight of 358 was also detected but cannot be identified. The amount of two important monacolins, compactin and monacolin K, were determined. It was found that the highest amount of compactin and monacolin K were 21.98 and 33.79 mg/g respectively when using Thai rice varity Oryza sativa L. cv. RD6 which was fermented without adding soybean milk. Keyword: Glutinous rice, HMG-CoA reductase, Monacolins, Monascus purpureus,Red yeast rice.