Stilbenoids biosynthesis

Stilbenoids are derived from cinnamic acid and three acetate units from mal-onyl coenzym A. The first part of the biosynthesis is in common to flavonoids. The two biosynthetic routes are diverging at the point of cyclization of a styryl-3,5,7-triketoheptanoic acid. A C-acylation produces a chalcone and subsequent modifications lead to the flavonoids. An aldol condensation of the same intermediate polyketide produces a stilbene-2-carboxylic acid that is unstable and constitutes a range of structures known as stilbenoids. Figure 9C.5 shows an overview of the biosynthetic pathway (Gorham 1995). 

The work on stilbenoids was reviewed by Gorham in 1995 [4]. Herein, we review the recent progress in the studies of stilbenoids with respect to their structure, distribution, extraction and isolation, technologies used in structure identification, synthesis and biosynthesis, and the last but not the least, bioactivities. The coverage of the new structures is from 1994 (especially those that have not been covered by Gorham [4]) to June 2006 (the references in 2006 may not be collected thoroughly as some of them might have not been included in the databases yet). 

In recent years great endeavor has been devoted to the biosynthesis of stilbene. Biosynthesis of simple stilbenes has been well characterized [4], and it only specifically requires the presence of stilbene synthase (STS) [366, 367]. There exists a balance between the stilbenoid and flavonoid biosyntheses [368]. The related research such as function of related gene sequences, molecular regulation of the biosynthesis process etc. could be referred to the literatures [369-371]. 

The biosynthesis of the stilbenoids, including 1, has been previously reviewed. Briefly, the synthesis of 1 is dependent upon a single key enzyme known as stilbene synthase or resveratrol synthase as part of a mixed phenylpropanoid-polyketide pathway [2,3,4,5,6] (Fig. (1)). Stilbene synthase catalyzes the formation of 1 through the condensation of one p-coumaroyl CoA and three malonyl CoA molecules, both of which are ubiquitous intermediary plant metabolites. 

Trantas E, Panopoulos N, Ververidis F (2009) Metabolic engineering of the complete pathway leading to heterologous biosynthesis of various flavonoids and stilbenoids in Saccharomyces-cerevisiae. MetabEng 11 355-366. doi 10.1016/j.ymben.2009.07.004... 

Horinouchi S (2008) Combinatorial biosynthesis of nmi-bacteiial and unnatural flavonoids, stilbenoids and curcuminoids by microorganisms. J Antibiot 61 709-728... 

Bibenzyls bioactivities biosynthesis bisbibenzyls occurrence oUgostilbenes phenanthrenes phytochemistry stilbenes stilbenoids... 

Adams M, Pacher T, Greger H, Bauer R (2005) Inhibition of leukotriene biosynthesis by stilbenoids from Stemona species. J Nat Prod 68 83-85... 

ACCase catalyzes the ATP-dependent carboxylation of acetyl-CoA, to form malonyl-CoA. Malonyl-CoA is the activated two-carbon unit which is used as the substrate in tlie biosynthesis of a variety of polyketide derivatives, including fatty acids, flavonoids, and stilbenoids. In addition, malonyl-CoA is used as the substrate for the malonation of a variety of plant phytochemicals. These metabolic fates of malonyl-CoA are separated into spatially and temporaly distinct compartments of the plant. Since malonyl-CoA cannot readily cross membranes, isozymes of ACCase that accumulate in different compartments of the plant provide an independent means of generating malonyl-CoA in each compartment. Depending upon the plant species that is examined, these isozymes of ACCase have homomeric or heteromeric quaternary sUnctures. 

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