Fig. 1
From: Optimizing yeast for high-level production of kaempferol and quercetin
Production of flavonoids kaempferol and quercetin in S. cerevisiae directly from glucose. L-Phenlalanine (L-Phe) derived from the shikimate and aromatic amino acid biosynthesis pathway is a precursor for p-coumaric acid formation. p-Coumaric acid is further catalyzed by a p-coumaric acid: CoA ligase (4CL), a chalcone synthase (CHS), a chalcone isomerase (CHI) to produce naringenin, which is an important junction to divaricate to different flavonoids. Naringenin can be further converted by a flavanone 3-hydroxylase (F3H) and flavonol synthase (FLS) to generate kaempferol, followed by a flavonoid monooxygenase (FMO) together with a cytochrome P450 reductase (CPR) to finaly give quercetin. Glc, glucose; alpha-KG, alpha-ketoglutarate