Monascus is a genusofmold. Among the known species of this genus, the red-pigmented Monascus purpureus is among the most important because of its use in the production of certain fermented foods in East Asia, particularly China and Japan.
Monascus purpureus derives its signature red color from mosascus pigment that is composed of azaphilones or secondary fungal metabolites.[2] There are six primary compounds all with similar biosynthetic pathways, two yellow pigments, ankaflavin and monascin, two orange pigments monascorubin and rubropunctain, and two red pigments monascorubinamine and rubropunctaimine.[3] All six are produced with a combination of polyketide synthase (PKS) and fatty acid synthase (FAS) In the first step a hexekatide is formed through Type 1 PKS encoded by the Mripig A gene.[4] PKS uses the domains acyl transferase, acetyl-CoA, ketoacyl synthase, acyl transferase, acyl carrier protein and the base units of acetyl-CoA and malonyl-CoA to produce a ketone chain that undergoes Knoevenagel aldol condensations.[4] The second step is the formation of a fatty acid through the FAS pathway.[3] The β-keto acid then undergoes a trans-esterification reaction to form one of the two orange pigments. At this point the compound can either undergo reduction to form one of the yellow pigments or amination to form one of the red pigments.[2]
