Direct NMR evidence for the equivalent participation of <scp>L</scp>-phenylalanine and <scp>L</scp>-tyrosine in the biosynthesis of the intermolecular Diels–Alder type adducts of prenylchalcone and prenylated 2-arylbenzofuran in <i>Morus</i> <i>alba</i> cell cultures

Hano, Yoshio; Nomura, Taro; Ueda, Shinichi

doi:10.1139/v94-003

Cited by 16 publications

(8 citation statements)

References 10 publications

(12 reference statements)

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“…[105] Addition of the O-methylated chalcone 229 to Morus alba cell cultures resulted in the formation of 230 as well as the Omethyl derivatives of kuwanon J (231) and chalcomoracin (232). [106] The structure of 230 indicates that prenylation occurs after aromatization of the cinnamoyl polyketide.…”

Section: Kuwanon J and Chalcomoracinmentioning

confidence: 99%

Chemistry and Biology of Biosynthetic Diels–Alder Reactions

2003

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Nature's repertoire of biosynthetic transformations has recently been recognized to include the Diels-Alder cycloaddition reaction. Evidence now exists that there are enzymes that mediate the Diels-Alder reaction in secondary metabolic biosynthetic pathways. 2002 marked the 100th anniversary of Alder's birth and 75 years since the discovery of the Diels-Alder reaction. It would appear that living systems discovered and made use of this ubiquitously useful ring-forming reaction eons ago for the construction of complex natural products. In this Review an overview is given of all of the known classes of natural products (polyketides, isoprenoids, phenylpropanoids, alkaloids) that have been speculated to arise by a biological Diels-Alder reaction.

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Section: Kuwanon J and Chalcomoracinmentioning

confidence: 99%

Chemistry and Biology of Biosynthetic Diels–Alder Reactions

2003

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“…Despite the assumption of enzyme-catalysed Diels-Alder type cycloaddition reactions occurring during the biosynthesis of natural products, e.g. polyketides, terpenoids and alkaloids, 32,33 relatively few examples of Diels-Alderase enzymes have been found. 34 From the results obtained in the current study, no evidence was provided for the involvement of a similar type of enzyme in the intermolecular [4ϩ2] cycloaddition reaction between two thiophene sulfoxide molecules to yield the racemic disulfoxides 7A-7G.…”

Section: (C) Trapping Of Transient 2-substituted Thiophene Oxides 6 F...mentioning

confidence: 99%

Dioxygenase-catalysed oxidation of monosubstituted thiophenes: sulfoxidation versus dihydrodiol formation

et al. 2003

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Toluene dioxygenase (TDO)-catalysed sulfoxidation, using Pseudomonas putida UV4, was observed for the thiophene substrates 1A-1N. The unstable thiophene oxide metabolites, 6A-6G, 6K-6N, spontaneously dimerised yielding the corresponding racemic disulfoxide cycloadducts 7A-7G, 7K-7N. Dimeric or crossed [4 + 2] cycloaddition products, derived from the thiophene oxide intermediates 6A and 6D or 6B and 6D, were found when mixtures of thiophene substrates 1A and 1D or 1B and 1D were biotransformed. The thiophene sulfoxide metabolite 6B was also trapped as cycloadducts 17 or 18 using stable dienophiles. Preferential dioxygenase-catalysed oxidation of the substituent on the thiophene ring, including exocyclic sulfoxidation (1H-1J) and cis-dihydroxylation of a phenyl substituent (1G and 1N), was also observed. An enzyme-catalysed deoxygenation of a sulfoxide in P. putida UV4 was noticed when racemic disulfoxide cyclo-adducts 7A, 7B and 7K were converted to the corresponding enantioenriched monosulfoxides 8A, 8B and 8K via a kinetic resolution process. The parent thiophene 1A and the 3-substituted thiophenes 1K-1N were also found to undergo ring dihydroxylation yielding the cis/trans-dihydrodiol metabolites 9A and 9K-9N. Evidence is provided for a dehydrogenase-catalysed desaturation of a heterocyclic dihydrodiol (9Kcis/9Ktrans) to yield the corresponding 2,3-dihydroxythiophene (24) as its preferred thiolactone tautomer (23). A simple model to allow prediction of the structure of metabolites, formed from TDO-catalysed bacterial oxidation of thiophene substrates 1, is presented.

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“…Simultaneous incorporation of [1-13 C]-L-phenylalanine and [3-13 C]-L-tyrosine into the cinnamoyl moiety of the chalcone derivative revealed the contribution of the two amino acids in the shikimate pathway [2,3]. The dimer of the prenylchalcone derivative such as kuwanon J [4] in M. alba cell cultures has been found to be formed through an intermolecular Diels-Alder type reaction [5].…”

mentioning

confidence: 99%

Sequential glucosylation determined by NMR in the biosynthesis of mulberroside D, a cis-oxyresveratrol diglucoside, in Morus alba L. cell cultures

Hano

Goi

Nomura

et al. 1997

CMLS, Cell. mol. life sci.

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Three new diglucosides, mulberrosides D, E, and F, were isolated from Morus alba cell cultures and their structures were established by spectroscopy. In the biosynthesis of mulberroside D, a cinnamoylpolyketide-derived cis-oxyresveratrol diglucoside in the cell cultures, the different ratio of 13 C-enrichment between two glucose moieties of mulberroside D, revealed by administering [U-13 C 6 ]-D-glucose and [1,3-13 C 2 ]glycerol to the cell cultures, suggested that two glucosylation steps in the biosynthesis of the glucoside occur with different time courses. .Morus alba callus and cell suspension cultures biosynthesize cinnamoyl-polyketide-derived chalcones and 2-arylbenzofurans with a prenyl group in high yields [1]. Simultaneous incorporation of [1-13 C]-L-phenylalanine and [3-13 C]-L-tyrosine into the cinnamoyl moiety of the chalcone derivative revealed the contribution of the two amino acids in the shikimate pathway [2,3]. The dimer of the prenylchalcone derivative such as kuwanon J [4] in M. alba cell cultures has been found to be formed through an intermolecular Diels-Alder type reaction [5]. Furthermore, it was found that two glucose catabolic pathways, the Embden-Meyerhof-Parnas pathway and the pentose phosphate cycle, participate in the biosynthesis of the the prenyl moiety [6,7]. This paper describes the structural determination of three new diglucosides, mulberrosides D, E, and F isolated from Morus alba cell cultures, and the biosynthesis of mulberroside D in the cell cultures. Materials and methodsThe induction of Morus alba callus cultures from seedlings or mulberry leaves has been described previously [1]. Morus alba cells suspended in sterile water (1 l) were incubated for 7 days at 25°C in the dark. After harvest and lyophilization, the lyophilized cells (3.2 g) were extracted with methanol (100 ml). The methanol solution was concentrated in vacuo to give a residue (0.65 g), which was extracted with acetone (50 ml) and the acetone-soluble and insoluble portions were separated. The acetone-insoluble portion (0.32 g) was subjected to high-pressure liquid chromatography (HPLC) with 70% methanol in water as solvent at a flow rate of 2 ml/min (column, Senshu Pak ODS-4251-N, 10 mm ¥× 250 mm). The eluate was monitored at 286 nm using an ultraviolet (UV) detector (Senshu Scientific Co., SSC 3000-B), and three new components, mulberrosides D (1, retention time, 26 min, 8 mg), E (2, retention time, 22 min, 2 mg) and F (3, retention time, 33 min, 3 mg), along with known compound, mulberroside A (4, retention time, 18 min, 4 mg) [8], were obtained ( fig. 1). The structures of these components were examined by spectroscopic methods. The fastatom bombardment (FAB) mass spectra were measured with a JEOL JMS DX-303 double-focusing mass spectrometer with JMA-DA 5000 data system, and the nuclear magnetic resonance (NMR) data were recorded on a JEOL JNM EX-400 FTNMR spectrometer at ambient temperature using methanol-d 4 as a solvent and tetramethyl silane (TMS) as an internal standard. All the material isolated wa...

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Direct NMR evidence for the equivalent participation of L-phenylalanine and L-tyrosine in the biosynthesis of the intermolecular Diels–Alder type adducts of prenylchalcone and prenylated 2-arylbenzofuran in Morus alba cell cultures

Cited by 16 publications

References 10 publications

Chemistry and Biology of Biosynthetic Diels–Alder Reactions

Chemistry and Biology of Biosynthetic Diels–Alder Reactions

Dioxygenase-catalysed oxidation of monosubstituted thiophenes: sulfoxidation versus dihydrodiol formation

Sequential glucosylation determined by NMR in the biosynthesis of mulberroside D, a cis-oxyresveratrol diglucoside, in Morus alba L. cell cultures

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