Stereochemistry of isoflavone reduction during pterocarpan biosynthesis: an investigation using deuterium nuclear magnetic resonance spectroscopy

Dewick, Paul M.; Ward, David

doi:10.1039/c39770000338

Cited by 30 publications

(6 citation statements)

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“…10,32 The docking study showed that the nicotinamide ring of NADPH would be present as an anti rotamer, and may attack the C2 atom of the substrate and transfer its 4-pro-R-hydride (i.e. H A hydrogen) to the pro-S position.…”

Section: Implications For Catalytic Mechanismmentioning

confidence: 99%

Crystal Structure of Isoflavone Reductase from Alfalfa (Medicago sativa L.)

Wang

Lin

et al. 2006

Journal of Molecular Biology

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Section: Implications For Catalytic Mechanismmentioning

confidence: 99%

Crystal Structure of Isoflavone Reductase from Alfalfa (Medicago sativa L.)

Wang

Lin

et al. 2006

Journal of Molecular Biology

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“…Both abstract the 4R-hydride from the NADPH cofactor during catalysis (1, 2, 5-8, [45][46][47], and each is regio-and enantiospecific toward its substrate (1, 2, 12, 45-47); i.e. for all of the IFRs identified to date, only the (Ϫ)-enantiomers of their products are formed, e.g.…”

Section: Resultsmentioning

confidence: 99%

“…To address the issue of whether PCBER-Pt1 displayed any enantiospecific effect toward its substrates, comparable with both PLR (1,12) and IFR (45)(46)(47), the products of enzymatic conversions of DDC 5 and DDDC 8 were evaluated by chiral HPLC analysis (see "Experimental Procedures"). Unlike the other members of this large family of reductases, however, PCBER-Pt1 showed no apparent enantiospecificity toward either substrate, with racemic products being formed (data not shown).…”

Section: Resultsmentioning

confidence: 99%

Evolution of Plant Defense Mechanisms

Gang¹,

Kasahara²,

Xia³

et al. 1999

Journal of Biological Chemistry

174

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Pinoresinol-lariciresinol and isoflavone reductase classes are phylogenetically related, as is a third, the so-called "isoflavone reductase homologs." This study establishes the first known catalytic function for the latter, as being able to engender the NADPH-dependent reduction of phenylcoumaran benzylic ethers. Accordingly, all three reductase classes are involved in the biosynthesis of important and related phenylpropanoidderived plant defense compounds. In this investigation, the phenylcoumaran benzylic ether reductase from the gymnosperm, Pinus taeda, was cloned, with the recombinant protein heterologously expressed in Escherichia coli. The purified enzyme reduces the benzylic ether functionalities of both dehydrodiconiferyl alcohol and dihydrodehydrodiconiferyl alcohol, with a higher affinity for the former, as measured by apparent K m and V max values and observed kinetic 3 H-isotope effects. It abstracts the 4R-hydride of the required NADPH cofactor in a manner analogous to that of the pinoresinol-lariciresinol reductases and isoflavone reductases. A similar catalytic function was observed for the corresponding recombinant reductase whose gene was cloned from the angiosperm, Populus trichocarpa. Interestingly, both pinoresinol-lariciresinol reductases and isoflavone reductases catalyze enantiospecific conversions, whereas the phenylcoumaran benzylic ether reductase only shows regiospecific discrimination. A possible evolutionary relationship among the three reductase classes is proposed, based on the supposition that phenylcoumaran benzylic ether reductases represent the progenitors of pinoresinol-lariciresinol and isoflavone reductases.

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“…hydride of the NADPH cofactor is abstracted and added to the si-face of the isoflavone substrate. That is, direct hydride transfer occurs at C 2 of the α,β-unsaturated ketone [a conjugated enone] in a strictly stereospecific manner (20), thereby taking up the pro-S position in the product, while the corresponding proton is added trans across the double bond to C 3 [see Figure 8C] (20)(21)(22).…”

Section: Proposed Enzymatic Mechanismsmentioning

confidence: 99%

Phylogenetic Links in Plant Defense Systems: Lignans, Isoflavonoids, and Their Reductases

Gang

Dinkova‐Kostova

Davin

et al. 1997

Phytochemicals for Pest Control

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Many lignans and isoflavonoids derived from (+)-pinoresinol/ (+)-lariciresinol and isoflavone reductases, respectively, have important roles in plant defense against pests and pathogens.In addition to their somewhat comparable physiological functions, other similarities are noted between these apparently unrelated branches of phenylpropanoid metabolism which suggest a phylogenetic link. These include similar enzymatic mechanisms, gene sequence homology, and putatively conserved protein phosphorylation sites for the pivotal branch point reductases, as well as comparable roles in [inducible] defense systems. Taken together with a detailed chemotaxonomic analysis of metabolite occurrence, it is proposed that during plant evolution, (+)-pinoresinol/(+)-lariciresinol reductase served as progenitor of the isoflavone reductases.Considerable emphasis continues to be placed upon deciphering, and ultimately biotechnologically exploiting, the natural defense mechanisms that plants employ in response to encroachment by herbivores, fungi, bacteria and viruses, e.g., as an attractive alternative to the application of pesticides, insecticides and other biocides. In this chapter, the intriguing parallels that have emerged between various lignans and isoflavonoids in plant chemical defenses are addressed. Both natural product classes appear to be derived from seemingly unrelated branches of phenylpropanoid and phenylpropanoid-acetate metabolism, which have originated in the early development of the modem seed plants [see (7) for a brief review of the phenylpropanoid pathway; and note that all references to angiosperm classification in this article are based on Dahlgren (2, 3)]. A number of similarities between the pathways has emerged, including striking homology of genes involved in presumed regulatory reductive steps, which leads to our reasoning that they are phylogenetically linked. Prior to elaboration of this hypothesis, a brief background on lignan and isoflavonoid nomenclature is necessary.

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Stereochemistry of isoflavone reduction during pterocarpan biosynthesis: an investigation using deuterium nuclear magnetic resonance spectroscopy

Cited by 30 publications

References 0 publications

Crystal Structure of Isoflavone Reductase from Alfalfa (Medicago sativa L.)

Crystal Structure of Isoflavone Reductase from Alfalfa (Medicago sativa L.)

Evolution of Plant Defense Mechanisms

Phylogenetic Links in Plant Defense Systems: Lignans, Isoflavonoids, and Their Reductases

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