Polyketide aromatic

LeeperFJ, Staunton J (1984) Biomimetic Syntheses of Polyketide Aromatics from Reaction of an Orsellinate Anion with Pyrones and a Pyrylium Salt. J Chem Soc Perkin Trans 1 1053... 

The ansa-chain of the ansamycins streptovaricins (4), rifamycins (263), geldanamycin (4), and herbimycin (32) has been shown to be polyketide in origin, being made up of propionate and acetate units with the 0-methyl groups coming from methionine. The remaining aromatic C N portion of the ansamacroHdes is derived from 3-amino-5-hydroxybenzoic acid (264—266) which is formed via shikimate precursors. Based on the precursors of the rifamycins and streptovaricins isolated from mutant bacteria strains, a detailed scheme for the biosynthesis of most of the ansamacroHdes has been proposed (95,263). 

Sheiko SS, Moller M (2001) Hyperbranched Macromolecules Soft Particles with Adjustable Shape and Capability to Persistent Motion. 212 137-175 Shen B (2000) The Biosynthesis of Aromatic Polyketides. 209 1-51 Shinkai S, see James TD (2002) 218 159-200 Shirakawa E, see Hiyama T (2002) 219 61-85 Shogren-Knaak M, see Imperial B (1999) 202 1-38 Sinou D (1999) Metal Catalysis in Water. 206 41-59... 

Quinones represent a very large and heterogeneous class of biomolecules. Three major biosynthetic pathways contribute to the formations of various quinones. The aromatic skeletons of quinones can be synthesized by the polyketide pathway and by the shikimate pathway. The isoprenoid pathways are involved in the biosynthesis of the prenyl chain and in the formation of some benzoquinones and naphthoquinones. ... 

From the cultures of streptomycetes were isolated anthacyclinones like aklavi-none. Various aromatic polyketide antibiotics produced by fungi and bacteria have quinoid structures, for example, doxorubicin, rhodomycin, and actinorhodin. ... 

Schneider, G., Enzymes in the biosynthesis of aromatic polyketide antibiotics, Curr. Opin. Struct. Biol., 15, 629, 2005. 

Figure 11.1 Representative secondary metabolites produced by Streptomyces ceolicolor and other microorganisms, including aromatic polyketides actinorhodin and tetrohydroxynaphthalene (a), side-rophore desferrioxamines (b), polyunsaturated fatty acid eicosapentaenoic acid (c) and terpenoids beta-...

There are at least three types of PKS. Type I PKSs catalyze the biosynthesis of macrolides such as erythromycin and rapamycin. As modular enzymes, they contain separate catalytic modules for each reaction catalyzed sequentially in the polyketide biosynthetic pathway. Type II PKSs have only a few active sites on separate polypeptides, and the active sites are used iteratively, catalyzing the biosynthesis of bacterial aromatic polyketides. Type III are fungal PKSs they are hybrids of type I and type II PKSs [49,50]. 

Recently, a new polyketide biosynthetic pathway in bacteria that parallels the well studied plant PKSs has been discovered that can assemble small aromatic metabolites.8,9 These type III PKSs10 are members of the chalcone synthase (CHS) and stilbene synthase (STS) family of PKSs previously thought to be restricted to plants.11 The best studied type III PKS is CHS. Physiologically, CHS catalyzes the biosynthesis of 4,2, 4, 6 -tetrahydroxychalcone (chalcone). Moreover, in some organisms CHS works in concert with chalcone reductase (CHR) to produce 4,2 ,4 -trihydroxychalcone (deoxychalcone) (Fig. 12.1). Both natural products constitute plant secondary metabolites that are used as precursors for the biosynthesis of anthocyanin pigments, anti-microbial phytoalexins, and chemical inducers of Rhizobium nodulation genes.12... 

MORITA, H., TAKAHASHI, Y., NOGUCHI, H., ABE, I., Enzymatic formation of unnatural aromatic polyketides by chalcone synthase, Biochem. Biophys. Res. Comm., 2000,279,190-195. 

Davis EM, Croteau R, Leeper FJ, Vederas JC (2000) Cyclization enzymes in the biosynthesis of monoterpenes, sesquiterpenes, and diterpenes. In Topics in current chemistry biosynthesis-aromatic polyketides, isoprenoids, alkaloids. Springer, Heidelberg, pp 53-95... 

Capon RJ, Steward M, Ratnayake R, Lacey E, Gill JH (2007) Citromycetins and Bilains A-C new Aromatic Polyketides and Diketopiperazines from Australian Marine-derived and Terrestrial Penicillium spp. J Nat Prod 70 1746... 

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