Yohei Katsuyama

Curcuminoids found in the rhizome of turmeric, Curcuma longa, possess various biological activities. Despite much attention regarding the biosynthesis of curcuminoids because of their pharmaceutically important properties and biosynthetically intriguing structures, no enzyme systems have been elucidated. Here we propose a pathway for curcuminoid biosynthesis in the herb C. longa, which includes two novel type III polyketide synthases. One of the type III polyketide synthases, named diketide-CoA

Curcuminoids are pharmaceutically important compounds isolated from the herb Curcuma longa. Two additional type III polyketide synthases, named CURS2 and CURS3, that are capable of curcuminoid synthesis were identified and characterized. In vitro analysis revealed that CURS2 preferred feruloyl-CoA as a starter substrate and CURS3 preferred both feruloyl-CoA and p-coumaroyl-CoA. These results suggested that CURS2 synthesizes curcumin or demethoxycurcumin and CURS3 synthesizes curcumin, bisdemetho

Curcuminoids, which are produced specifically by plants of the order Zingiberales, have long been used as food additives because of their aromatic, stimulant and colouring properties and as traditional Asian medicines because of their anti-tumour, antioxidant and hepatoprotective activities. Curcuminoids are therefore attractive targets for metabolic engineering. An artificial curcuminoid biosynthetic pathway, including reactions of phenylalanine ammonia-lyase (PAL) from the yeast Rhodotorula ru

Curcuminoids, major components of the spice turmeric, are used as a traditional Asian medicine and a food additive. Curcumin, a representative curcuminoid, has received a great deal of attention because of its anti-inflammatory, anticarcinogenic, and antitumor activities. Here we report a novel type III polyketide synthase named curcuminoid synthase from Oryza sativa, which synthesizes bisdemethoxycurcumin via a unique mechanism from two 4-coumaroyl-CoAs and one malonyl-CoA. The reaction begins

Stilbenes are bioactive compounds that show beneficial effects for humans, such as anti-tumor activity and survival improvement. Resveratrol, a representative of stilbenes and showing various health-improving activities, is rapidly metabolized in humans, and modified resveratrols are therefore desired as anti-cancer drugs and dietary polyphenols. An Escherichia coli system, in which an artificial stilbene biosynthetic pathway, including steps of phenylalanine ammonia-lyase, 4-coumarate:CoA ligas

We have established a sequencing based typing (SBT) method for detection of genetic polymorphism in the exon 2 to 4 domains of the major histocompatibility complex (MHC) class I chain-related gene A (MICA) and applied it to allele typing of 130 healthy Japanese individuals. A 2.2-kb segment including exons 2, 3 and 4 of the MICA gene was amplified by a pair of generic primers followed by cycle sequencing using exon-specific nested primers. In total, 8 alleles were observed in a Japanese populati

DON (6-diazo-5-oxo-l-norleucine), a diazo-containing amino acid, has been studied for more than 60 years as a potent antitumor agent, but its biosynthesis has not been elucidated. Here we reveal the complete biosynthetic pathway of alazopeptin, the tripeptide Ala-DON-DON, which has antitumor activity, by gene inactivation and in vitro analysis of recombinant enzymes. We also established heterologous production of N-acetyl-DON in Streptomyces albus. DON is synthesized from lysine by three enzymes

While type II polyketide synthases (PKSs) are known for producing aromatic compounds, a phylogenetically new subfamily of type II PKSs have been recently proposed to synthesize polyene structures. Here we report in vitro analysis of such a type II PKS, IgaPKS for ishigamide biosynthesis. The ketoreductase (Iga13) and dehydratase (Iga16) were shown to catalyze the reduction of a β-keto group and dehydration of a β-hydroxy group, respectively, to form a trans double bond. Incubation of the acyl ca

Curcuminoids, natural products in the rhizome of turmeric, show various biological activities, including antioxidant and antitumor activities. For this reason, curcuminoids have been focused on as potential pharmaceuticals. Exogenous supplementation with various carboxylate precursors in genetically engineered Escherichia coli cells carrying an artificially assembled pathway for curcuminoid biosynthesis led to the production of 17 unnatural curcuminoids.