Monascus spp

The fermentation products of Monascus, especially those produced by solid-state fermentation of rice, have been used as food and health remedies for over 1000 years in China. Monascus rice products (MRPs) are currently being used as health foods in the United States and many Asian countries such as Japan, Taiwan, China, Korea, Thailand, the Philippines, and Indonesia. Many studies have shown that Monascus spp. produce commercially viable metabolites, including food colorants, cholesterol-lowering agents, and antibiotics. The most important bioactive compound isolated from Monascus is monacolin K, which is identical to the potent cholesterol-lowering, antiatherosclerotic drug lovastatin, a 3-hydroxy-3-methylglutaryl... 

Monascus spp. have been used as foods and medicines in the Orient for over 1000 years (Wong, 1982). In China and Taiwan, it has been called "Hong Qu," "Hon-Chi," "Anka," or "Ang-kak" using the Chinese or Taiwanese phonetic alphabet. The Japanese use the name "Beni Koji" or "red Koji." In the United States and Europe, it has been called "red rice," "red-mold rice," or "red Chinese rice." Many publications and commercial products use "red yeast rice," which is not an appropriate name for filamentous fungi. 

FIGURE 1 The morphology of Monascus spp. observed under optical microscope (Panel A) and scanning electron microscopy (SEM) (Panel B). 

Traditionally, MRP is cultivated on steamed rice until the mycelium totally covers the whole surface of the grains and the product is used directly (Lotong, 1985 Su and Wang, 1983). Because large quantities of secondary metabolites and hydrolytic enzymes, such as a-amylase, /1-amylase, glucoamylase, protease, and lipase, are produced by Monascus spp., MRP is widely used as a preservative for meat and fish... 

Many secondary metabolites with complex chemical structures, including pigments (Figure 2) and monacolins (Figure 2), are synthesized from the polyketide pathway in Monascus spp. (Simpson, 1986). Several effectors controlling the polyketide synthesis of Monascus have been reported by using submerged culture systems (Lin, 1991). Considerable research has been conducted on the industrial production of Monascus in complex liquid media (Shepherd and Carels, 1983). 

Initially identified from Monascus spp., monacolin K (C24H36O5) is a polyketide, which is structurally identical to lovastatin (Endo, 1979, 1980). In addition to monacolin K, there are several other minor monacolins (Ma et al., 2000). At least six structurally related monacolins have been identified from the genus Monascus, namely monacolin J, K, L, and X, dihydromonacolin K, and dihydromonacolin L (Endo et al., 1985a,b). 

Since the formation of the secondary metabolites of the Monascus spp. is affected by cultivation conditions, Lee et al. (2006) used sweet potato (Ipomoea batatas), potato Solanum tuberosum), cassava (Manihot esculenta), and dioscorea (Dioscorea batatas) as the substrates to identify the best choice for monacolin K production. The results showed that M. purpureus NTU 301, with dioscorea as the substrate, could produce monacolin K at 2584 mg/kg, which is 5.37 times more than that resulted when rice is used as the substrate. 

Trichodiene (49 Scheme 1) has been detected as a volatile product of Monascus purpureus and of Stachybotrys atra, but the trichothecene relatives (Table 8), including, possibly, the loukacinols (see note c), are essentially products of Fusarium spp. and T. roseum. 

Mevastatin (compactin) and lovastatin (mevinolin) are fungal fermentation products naturally produced by certain higher fungi. Mevastatin was first isolated by Akira Endo and co-workers in the 1970s from Penicillium citri-num Lovastatin is produced by Pleurotus ostreatus (oyster mushroom) and closely related to Pleurotus spp. as well as to Monascus purpureus (Chinese red yeast rice). Both mevastatin and lovastatin have a powerful inhibitory effect on HMG-CoA reductase. Discovered in the 1970s, they were taken into clinical development as potential dmgs... 

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