Monascus pigments having yellow, orange, and red colors are widely studied for their potential beneficial properties. Many different biological activities have been reported regarding Monascus pigments and their derivatives, but the usual method is to test complex extracts from the mycelium of the fungus or from a fungus-fermented substrate. However, this review is mainly concerned with the biological activities of purified Monascus pigments. Both yellow (ankaflavin, monascin) and red (rubropunctamine, monascorubramine) Monascus pigments are proven antioxidants if used in concentrations of 10 μg/mL or higher. Antimicrobial activity against Gram-positive and Gram-negative bacteria and fungi has been observed with all Monascus pigments. However, the best antimicrobials are red Monascus pigments, and their amino acid derivatives (l-cysteine derivatives have MIC 4 μg/mL against Enterococcus faecalis). Yellow monaphilones and orange monaphilols seem to have the highest anti-inflammatory activity (IC50 1.7 μM of monaphilol D) and, together with red Monascus pigment derivatives, have mild antiobesity and antidiabetic activities. Further, monascin and ankaflavin in daily doses of 0.5 and 0.08 mg, respectively, lowered serum blood levels of low-density lipoprotein cholesterol complexes in rats on a high-fat diet. Orange Monascus pigments, rubropunctatin and monaphilols A and C, exhibit cytotoxic and antitumor activities (IC50 8-10 μM).

• MeSH
• Anti-Bacterial Agents pharmacology   chemistry   isolation & purification   MeSH
• Anti-Inflammatory Agents pharmacology   chemistry   isolation & purification   MeSH
• Anti-Infective Agents pharmacology   chemistry   isolation & purification   MeSH
• Antioxidants pharmacology   chemistry   isolation & purification   MeSH
• Pigments, Biological * pharmacology   chemistry   isolation & purification   MeSH
• Flavins pharmacology   chemistry   MeSH
• Gram-Positive Bacteria drug effects   MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Molecular Structure MeSH
• Monascus * chemistry   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• ankaflavin MeSH Browser
• Anti-Bacterial Agents MeSH
• Anti-Inflammatory Agents MeSH
• Anti-Infective Agents MeSH
• Antioxidants MeSH
• Pigments, Biological * MeSH
• Flavins MeSH
• Heterocyclic Compounds, 3-Ring MeSH
• monascin MeSH Browser

The Monascus fungi have traditionally been used in Asia for food coloring. Unfortunately, the most well-known species, Monascus purpureus, very often produce mycotoxin citrinin in addition to pigments, which poses a significant problem for the use of pigments in foods. There is a step in pigment biosynthesis where a side chain of five or seven carbons is attached to the tetraketide, the product of polyketide synthase, resulting in the formation of pigments in pairs. Further, it is still unclear whether pigment and citrinin biosyntheses are related or independent. Therefore, this study is focused on the relationship between pigment and citrinin production and pigment analogues that differ in side chain length, all evaluated by the Spearman correlation test. To generate sufficient data, Monascus purpureus DBM 4360 was cultivated with different carbon and nitrogen sources and under osmotic stress induced by glucose and/or sodium chloride. The study reveals a very strong correlation between the production of five- and seven-carbon side chain pigments under all culture conditions tested for all three groups, yellow, orange, and red pigments. The correlation between pigments and citrinin depended on the group assessed and ranged from fair to very strong. While the coordinated synthesis of pigment analogues in pairs has been clearly confirmed, the relationship between pigment and citrinin production was unfortunately neither confirmed nor refuted and must be the subject of further research.

• Keywords
• Monascus purpureus, citrinin, pigments, regulation of secondary metabolites biosynthesis, stress conditions,
• MeSH
• Pigments, Biological * chemical synthesis   MeSH
• Citrinin * biosynthesis   chemistry   MeSH
• Nitrogen metabolism   MeSH
• Culture Techniques MeSH
• Monascus * chemistry   growth & development   metabolism   MeSH
• Osmotic Pressure physiology   MeSH
• Carbon metabolism   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Pigments, Biological * MeSH
• Citrinin * MeSH
• Nitrogen MeSH
• Carbon MeSH

The fungus Monascus is a well-known source of secondary metabolites with interesting pharmaceutical and nutraceutical applications. In particular, Monascus pigments possess a wide range of biological activities (e.g. antimicrobial, antioxidant, anti-inflammatory or antitumoral). To broaden the scope of their possible application, this study focused on testing Monascus pigment extracts as potential photosensitizing agents efficient in antimicrobial photodynamic therapy (aPDT) against bacteria. For this purpose, eight different extracts of secondary metabolites from the liquid- and solid-state fermentation of Monascus purpureus DBM 4360 and Monascus sp. DBM 4361 were tested against Gram-positive and Gram-negative model bacteria, Bacillus subtilis and Escherichia coli and further screened for ESKAPE pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. To the bacterial culture, increasing concentration of extracts was added and it was found that all extracts showed varying antimicrobial activity against Gram-positive bacteria in dark, which was further increased after irradiation. Gram-negative bacteria were tolerant to the extracts' exposure in the dark but sensitivity to almost all extracts that occurred after irradiation. The Monascus sp. DBM 4361 extracts seemed to be the best potential candidate for aPDT against Gram-positive bacteria, being efficient at low doses, i.e. the lowest total concentration of Monascus pigments exhibiting aPDT effect was 3.92 ± 1.36 mg/L for E. coli. Our results indicate that Monascus spp., forming monascuspiloin as the major yellow pigment and not-forming mycotoxin citrinin, is a promising source of antimicrobials and photoantimicrobials.

• MeSH
• Anti-Bacterial Agents * pharmacology   chemistry   MeSH
• Pigments, Biological pharmacology   MeSH
• Biological Products pharmacology   chemistry   MeSH
• Photochemotherapy MeSH
• Photosensitizing Agents pharmacology   chemistry   MeSH
• Gram-Positive Bacteria drug effects   radiation effects   MeSH
• Complex Mixtures pharmacology   chemistry   MeSH
• Microbial Sensitivity Tests * MeSH
• Monascus * chemistry   metabolism   MeSH
• Mycelium * chemistry   radiation effects   drug effects   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• red yeast rice MeSH Browser

The pink-red color of traditional sausages (cured meat) is the result of nitrite addition and the formation of nitrosomyoglobin. However, the pleasant color of processed meat products is a side effect of nitrite addition while the main anticipated goal is to suppress the germination of clostridial spores. The fungus Monascus is known as a producer of oligoketide pigments, which are used in Asian countries, especially in China, for coloring foods, including meat products. Although, different biological activities of Monascus pigments have been tested and confirmed in many studies, their effect on germination of bacterial spores has never been investigated. This study is focused on testing the activity of red yeast rice (RYR) extract, containing monascin, rubropunctatin, rubropunctamine complexes and monascuspiloin as the main pigments, on germination of Clostridium and Bacillus spores. It was found that addition of nitrite alone, at the permitted concentration, had no effect on spore germination. However, the combined effects of nitrite with NaCl, tested after addition of pickling salt, was efficient in inhibiting the germination of C. beijerinckii spores but had no effect on B. subtilis spores. In contrast, total suppression of C. beijerinckii spore germination was reached after addition of RYR extract to the medium at a concentration of 2% v/v. For B. subtilis, total inhibition of spore germination was observed only after addition of 4% v/v RYR extract to the medium containing 1.3% w/w NaCl.

• Keywords
• Bacillus subtilis, Clostridium beijerinckii, Monascus, bacterial spores germination, nitrite, red yeast rice,
• Publication type
• Journal Article MeSH