Production of Monacolin K in Monascus Pilosus: Comparison between Industrial Strains and Analysis of Its Gene Clusters

Monascus pilosus strains are widely applied to yield a cholesterol synthesis inhibitor monacolin K (MK), also called lovastatin (LOV). However, the mechanism of MK production by M. pilosus strains is still unclear. In this study, we firstly confirmed four Monascus strains, MS-1, YDJ-1, YDJ-2, and K104061, isolated from commercial MK products as M. pilosus and compared their abilities to produce MK in solid-state and liquid-state cultures. Then, we sequenced and analyzed their genomes and MK biosynthetic gene clusters (BGCs). The results revealed that the MK yields of MS-1, YDJ-1, YDJ-2, and K104061 in solid-state cultures at 14 days were 6.13, 2.03, 1.72, and 0.76 mg/g, respectively; the intracellular and extracellular MK contents of MS-1, YDJ-1, YDJ-2, and K104061 in liquid-state cultures at 14 days reached 0.9 and 1.8 mg/g, 0.38 and 0.43 mg/g, 0.30 and 0.42 mg/g, and 0.31 and 0.76 mg/g, respectively. The genome sizes of the four M. pilosus strains were about 26 Mb, containing about 7000–8000 coding genes and one MK gene cluster. The MK BGCs of MS-1, YDJ-2, and K104061 contained 11 genes, and the MK BGC of YDJ-1 contained 9 genes. According to the literature search, there are few comparisons of gene clusters and related genes responsible for the synthesis of LOV and MK. We also compared the LOV BGC in A. terreus with the MK BGCs in different species of Monascus spp., and the results revealed that although LOV and MK were the same substance, the genes responsible for the synthesis of MK were much less than those for LOV synthesis, and the gene functions were quite different. The current results laid a foundation to explore the mechanism of MK produced by Monascus spp. and compare the synthesis of LOV and MK.

Screening of Azaphilone Derivatives From Monascus pilosus-Fermented Rice (Red Yeast Rice) and Their Evaluation as Nonsteroidal Androgen Receptor Antagonists

Monascus pilosus BCRC 38093 is a mutant strain of M. pilosus BCRC 38072. The 95% ethanol extract of red yeast rice fermented by M. pilosus BCRC 38093 showed 4 major signals on high performance liquid chromatography (HPLC) examination. The extraction of metabolites and chromatography of the ethyl acetate crude extract on silica gel yielded 2 azaphilone derivatives, monascin (1) and monascinol (2), and 2 monacolin-type derivatives, acid-form monacolin K (3) and lactone-form monacolin K (4). Their structural characterization was elucidated by spectroscopic techniques ultraviolet-visible (UV), infrared spectroscopy (IR), and two dimensional-nuclear magnetic resonance (2D-NMR) and mass spectrometry. These compounds were assayed for their anti-androgen activity; monascinol (2) exhibited strong activity.

A Randomized Clinical Efficacy Trial of Red Yeast Rice (Monascus pilosus) Against Hyperlipidemia

Red yeast rice (RYR) has been used as an alternative treatment for hyperlipidemia. According to the previous studies, other compounds, besides monacolin K in RYR, may also reduce the serum lipid level. This study aims at examining the efficacy of monacolin K-rich and Gamma-Aminobutyric Acid (GABA)-rich RYR (Monascus pilosus) with regards to treating hyperlipidemia in a randomized control, double-blind clinical trial. In the research, we assigned 50 eligible subjects to monacolin K-rich RYR, GABA-rich RYR and placebo groups ([Formula: see text], 17, 17, respectively). The concentrations of TC, LDL-C, HDL, TG and blood biochemical data were evaluated at different phases: before applying (visit 1), after 1-month (visit 2), 2-month (visit 3), 3-month (visit 4) of providing the intervention and 1-month after ending the test food (visit 5) among three groups. During the 3-month intervention, the serum TC and LDL-C levels decreased significantly in the monacolin K group compared to the baseline and the other two groups. The Serum TG level declined steadily but was not statistically significant. Meanwhile, no marked differences in the serum HDL level were revealed among the three groups. Most safety assessment data had minor variation except two subjects (in monacolin K and GABA group separately) reported elevated liver enzymes. Monacolin K-rich RYR can reduce cholesterol as expected, while the GABA-rich RYR performed non-significant reduction on serum triglyceride. The research results demonstrate that using different concentrations and ratios between monacolin K and GABA could be beneficial for antihyperlipidemia.