Curcumin biosynthesis

Fig. 1 Biosynthesis of plant polyphenols by CHS-superfamily type III PKSs. CHS chalcone synthase STS stilbene synthase ACS acridone synthase VPS valerophenone synthase SPS styrylpyrone synthase BPS benzophenone synthase OAS olivetolic acid synthase 2PS 2-pyrone synthase BAS benzalacetone synthase CUS curcumin synthase...

Neema, A. (2005) Investigations on the biosynthesis of curcumin in turmeric (Curcuma longa L.). PhD thesis, Calicut University, Kerala, India, p. 171. 

Roughley, P.J. and Whiting, D.A. (1973) Experiments in the biosynthesis of curcumin. Journal of the Chemical Society - Perkin Transactions- 20, 2379-2388. 

The constitution of this relatively simple and broadly used compound was established surprisingly late by Lampe and Milobedzka (2), first in 1910 by degradation followed in 1913 by a synthesis (3,4). Curcumin remained the only representative of the group as long as until 1964. In the following 30 years, however, about 70 linear and 35 macrocylic diarylheptanoids were isolated. In the present review we are dicussing their chemistry, phytochemistry, biosynthesis, biological activity, and synthesis. 

Katsuyama Y, Hirose Y, Funa N, Ohnishi Y, Horinouchi S (2010) Precursor-directed biosynthesis of curcumin analogs in Escherichia coli. Biosci Biotechnol Biochem 74 641-645... 

Biosynthesis of curcuminoids is similar to the biosynthesis of phenylpropanoids, such as flavonoids. Intermediates, such as 4-coumaroyl-CoA, condense with malonyl-CoA (via diketide as an intermediate) to form bisdemethoxycurcumin. Curcumin arises by subsequent oxidation and methylation of bisdemethoxycurcumin. 

Curcuma extract, volatile oil, and its curcumin components have in vitro and in vivo antiinflammatory activity that may be due to inhibition of eicosanoid (leukotrienes/thrombox-anes) biosynthesis. A fraction of curcuma oil (b.p 80-110 °C) has been demonstrated to have anti-inflammatory and antiarthritic activities in rats. An essential oil-depleted extract is effective against experimental rheumatoid arthritis. Involved targets include NF-kB, che-mokine, COX-2, and others. Curcumin has also been reported to exhibit antiedemic effects in rats (martestdale). 

A study of the biosynthesis of curcumin (130) has produced unexpected results. Administration of labelled acetate, malonate, and phenylalanine to Curcuma longa plants revealed that all of these substrates were implicated in the biosynthetic route. Previous biosynthetic proposals suggested that the most plausible biosynthesis of curcumin (130) would involve condensation of two cinnamate or ferulate (128) units (derived from phenylalanine) and one acetate or malonate unit However, the recent studies have shown that the majority of radioactivity from acetate and malonate was not confined to the central methine carbon atom of curcumin (130). Since [l- C]phenylalanine was incorporated specifically, the high incorporation of activity from acetate/malonate into the aromatic regions of curcumin has been rationalized in terms of a biosynthetic route (Scheme 22) in which a P-pentaketo-acid derivative (132) is postulated as an intermediate. Further experimental evidence in support of these proposals is anticipated. 

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