Biosynthesis of the aglycone of chartreusin in Streptomyces sp. X-465

Brown, Jeffrey R.; Spring, M. S.; Stoker, J.R.

doi:10.1016/s0031-9422(00)97197-8

Cited by 14 publications

(10 citation statements)

References 20 publications

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“…all of the non-glycosidic signals not intensified in the sample labeled from [l-13C]-acetate were enhanced in the sample from [2-13C]acetate. This result verifies the earlier deductions based on radiotracer studies that all of the aglycone carbon atoms are derived from acetate (1,2). In the spectrum of the sample labeled from [1,2-13C]acetate, signals for 16 of the 19 aglycone carbons were accompanied by satellites due to 13C-13c coupling between covalently bonded 13C carbon atoms.…”

Section: Biosynthetic Labelingsupporting

confidence: 89%

“…confirm that C-3 and C-9 originated with the Streptomyces chartreusis produces a glycosidic carbox~l and meth~lene carbons of malonate, antibiotic, chartreusin, the aromatic &lactone and that the relative specific activities of subcomponent of which has been reported to stituted phthalic acids containing the carbon originate from acetate (1,2). Schmid located the atoms of rings A and C were consistent with the carbon atoms derived from the and car-distribution of label reported by Schmid.…”

Section: Introductionsupporting

confidence: 78%

“…Supporting these assignments, the resonance attributed to C-3 was enhanced in the spectrum of the metabolite enriched with [I-13C]acetate, as predicted from the radiotracer study (2) which established that C-3 was derived from the carbonyl carbon of acetate. The longrange coupling (3JcH 3.1 HZ) at C-4 must involve H-5.…”

Section: Assignment Of 3~ Resonancesmentioning

confidence: 60%

“…Of the three other resonances, those at 6, 138.4 and 6, 158.3 pprn were enhanced in the spectrum of chartreusin biosynthesized from [1-13C]acetate whereas the carbon atom with a chemical shift of 6, 163.6 pprn was derived from the methyl group of acetate. Since the earlier radiotracer study (2) For personal use only.…”

Section: Assignment Of 3~ Resonancesmentioning

confidence: 99%

“…labeled molecule has been described. Even if the Brown et al (2) examined the distribution of proposed labeling Pattern is assumed to be 14C-labeled carbon atoms in chartreusin en-correct, the manner in which acetate and riched by growing cultures of S. chartreusis on malonate units are assembled to generate char&ethyl [I-14C] or [2-l4CImalonate. By chemical treusin aglycone is not obvious.…”

Section: Introductionmentioning

confidence: 99%

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Use of ¹³C in biosynthetic studies. Incorporation of ¹³C-labeled acetate into chartreusin by Streptomyceschartreusis

Canham¹,

Vining²,

McInnes³

et al. 1977

Can. J. Chem.

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Examination by 13C nuclear magnetic resonance spectroscopy of chartreusin produced in cultures of Streptomyces chartreusis supplemented with [I-13C] and [2-13C]acetate showed that the 19-carbon aglycone component was derived entirely from acetate. In the spectrum of chartreusin enriched from [1,2-13C]acetate the signals for 16 of the carbon atoms were accompanied by satellites due to spin-spin coupling of intact 13C-13C units. The coupled pairs were matched with the aid of homonuclear single 3C-frequency decoupling. Of the uncoupled carbon atoms, two were derived from methyl groups of acetate and the third came from an acetate carboxyl group. The arrangement of paired and unpaired 13C atoms in chartreusin suggests that the aglycone is derived from a single 22-carbon polyketide chain. Cyclization to a benzpyrene-like intermediate followed by ring cleavage and loss of three carbon atoms provides a plausible route from the polyketide to the substituted isocoumarin structure of the aglycone.

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Section: Biosynthetic Labelingsupporting

confidence: 89%

Section: Introductionsupporting

confidence: 78%

Section: Assignment Of 3~ Resonancesmentioning

confidence: 60%

Section: Assignment Of 3~ Resonancesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Use of ¹³C in biosynthetic studies. Incorporation of ¹³C-labeled acetate into chartreusin by Streptomyceschartreusis

Canham¹,

Vining²,

McInnes³

et al. 1977

Can. J. Chem.

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An NADPH‐Dependent Ketoreductase Catalyses the Tetracyclic to Pentacyclic Skeletal Rearrangement in Chartreusin Biosynthesis

Jiao

Wang

et al. 2021

Angewandte Chemie

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Redox tailoring enzymes play key roles in generating structural complexity and diversity in type II polyketides. In chartreusin biosynthesis, the early 13 C-labeling experiments and bioinformatic analysis suggest the unusual aglycone is originated from a tetracyclic anthracyclic polyketide. Here, we demonstrated that the carbon skeleton rearrangement from a linear anthracyclic polyketide to an angular pentacyclic biosynthetic intermediate requires two redox enzymes. The flavin-dependent monooxygenase ChaZ catalyses a Baeyer-Villiger oxidation on resomycin C to form a seven-membered lactone. Subsequently, a ketoreductase ChaE rearranges the carbon skeleton and affords the a-pyrone containing pentacyclic intermediate in an NADPH-dependent manner via tandem reactions including the reduction of the lactone carbonyl group, Aldol-type reaction, followed by a spontaneous glactone ring formation, oxidation and aromatization. Our work reveals an unprecedented function of a ketoreductase that contributes to generate structural complexity of aromatic polyketide.

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An NADPH‐Dependent Ketoreductase Catalyses the Tetracyclic to Pentacyclic Skeletal Rearrangement in Chartreusin Biosynthesis

et al. 2021

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Redox tailoring enzymes play key roles in generating structural complexity and diversity in type II polyketides. In chartreusin biosynthesis, the early 13C‐labeling experiments and bioinformatic analysis suggest the unusual aglycone is originated from a tetracyclic anthracyclic polyketide. Here, we demonstrated that the carbon skeleton rearrangement from a linear anthracyclic polyketide to an angular pentacyclic biosynthetic intermediate requires two redox enzymes. The flavin‐dependent monooxygenase ChaZ catalyses a Baeyer–Villiger oxidation on resomycin C to form a seven‐membered lactone. Subsequently, a ketoreductase ChaE rearranges the carbon skeleton and affords the α‐pyrone containing pentacyclic intermediate in an NADPH‐dependent manner via tandem reactions including the reduction of the lactone carbonyl group, Aldol‐type reaction, followed by a spontaneous γ‐lactone ring formation, oxidation and aromatization. Our work reveals an unprecedented function of a ketoreductase that contributes to generate structural complexity of aromatic polyketide.

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Biosynthesis of the aglycone of chartreusin in Streptomyces sp. X-465

Cited by 14 publications

References 20 publications

Use of ¹³C in biosynthetic studies. Incorporation of ¹³C-labeled acetate into chartreusin by Streptomyceschartreusis

Use of ¹³C in biosynthetic studies. Incorporation of ¹³C-labeled acetate into chartreusin by Streptomyceschartreusis

An NADPH‐Dependent Ketoreductase Catalyses the Tetracyclic to Pentacyclic Skeletal Rearrangement in Chartreusin Biosynthesis

An NADPH‐Dependent Ketoreductase Catalyses the Tetracyclic to Pentacyclic Skeletal Rearrangement in Chartreusin Biosynthesis

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Biosynthesis of the aglycone of chartreusin in Streptomyces sp. X-465

Cited by 14 publications

References 20 publications

Use of 13C in biosynthetic studies. Incorporation of 13C-labeled acetate into chartreusin by Streptomyceschartreusis

Use of 13C in biosynthetic studies. Incorporation of 13C-labeled acetate into chartreusin by Streptomyceschartreusis

An NADPH‐Dependent Ketoreductase Catalyses the Tetracyclic to Pentacyclic Skeletal Rearrangement in Chartreusin Biosynthesis

An NADPH‐Dependent Ketoreductase Catalyses the Tetracyclic to Pentacyclic Skeletal Rearrangement in Chartreusin Biosynthesis

Contact Info

Product

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Use of ¹³C in biosynthetic studies. Incorporation of ¹³C-labeled acetate into chartreusin by Streptomyceschartreusis

Use of ¹³C in biosynthetic studies. Incorporation of ¹³C-labeled acetate into chartreusin by Streptomyceschartreusis