Hydroxylations and Methylations of Quercetin, Fisetin, and Catechin byStreptomycesgriseus

Hosny, Mohammed; Dhar, Kajari; Rosazza, John P. N.

doi:10.1021/np000457m

Cited by 52 publications

(40 citation statements)

References 44 publications

(92 reference statements)

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“…Of them, the 13 C NMR data of three derivatives were already published. 5,6,7 Because only the partial NMR data of others have been known, however, the complete assignments of their 1 H and 13 C NMR data are reported here. One of the 13 C NMR data published previously showed the incorrect 13 C NMR data, thus their corrected values were determined in this study.…”

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confidence: 99%

Effects of Hydroxy and Methoxy Substituents on NMR Data in Flavonols

2008

Bulletin of the Korean Chemical Society

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Kaempferide, kaempferol, and galangin belong to flavonol, one of flavonoid classes. Even they have the same moiety as flavonol, their binding affinities for a hexahistidine-tagged C-terminal nucleotide-binding domain are different with each other.1 The dissociation constants of flavonol, kaempferide, kaempferol, and galangin are 10.1, 4.5, 6.7, and 5.3 mM, respectively. Galangin contains two more hydroxyl groups than flavonol, and kaempferol has three more hydroxyl groups. Kaempferide differs with kaempferol in only one substituent: 4'-hydroxyl group of kaempferol is switched to 4'-methoxyl group in kaempferide. Likewise, galangin and kaempferide show different enzymatic kinetic parameters, V max /K m , for cytochrome P450 isomers CYP2C9 and CYP1A1 which take an important role in oxidative metabolism of galangin and kaempferide. The values of V max /K m of galangin for CYP2C9 and CYP1A1 were 59.0 and 10.2 μL/min/mg, respectively, and those of kaempferide were 5.1 and 1.9, respectively.2 While kaempferide has 4'-methoxyl group, galangin does not have it. As a result, it can be considered that the substitution of hydroxyl or/and methoxyl groups on flavonols results in significant changes of the biological activities. Flavonol derivatives are being found still from natural sources. One of the best methods to identify them is NMR spectroscopy. 3,4 Since the substitution of hydroxyl or/and methoxyl groups causes the chemical shift changes in the 1 H and 13 C NMR spectra, the elucidation of the effects of substituents on the chemical shifts in flavonol derivatives may help us predict the structures of the unknown compounds based on the simple one dimensional NMR experiments.In order to elucidate the substituent effects of chemical shifts on flavonol derivatives, the NMR experiments of flavonol (1) and nine flavonol derivatives (2-10) were carried out in this study. Of them, the 13

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confidence: 99%

Effects of Hydroxy and Methoxy Substituents on NMR Data in Flavonols

2008

Bulletin of the Korean Chemical Society

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“…Flavones have also been implicated in various physiological activities, such as antioxidants, phytoestrogens in controlling breast cancer incidence, and osteogenesis, for example, and in chemotaxis of nitrogen-fixing bacteria (23,24,34). Considering this, there has been an increasing interest in the production of novel compounds from flavones using microbial reactions (25,26,37). Previously, biphenyl dioxygenase from P. pseudoalcaligenes KF707 was shown to produce cis-2Ј,3Ј-dihydrodiol on the B ring of flavone (33).…”

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confidence: 99%

Epoxide Formation on the Aromatic B Ring of Flavanone by Biphenyl Dioxygenase of Pseudomonas pseudoalcaligenes KF707

Han

Kim

Jung

et al. 2005

Appl Environ Microbiol

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Prokaryotic dioxygenase is known to catalyze aromatic compounds into their corresponding cis-dihydrodiols, however, we found that the same enzyme showed dioxygenase activity toward flavone, resulting in the production of flavone cis-2,3-dihydrodiol. Extensive structural identification of the metabolites of flavanone by using high-pressure liquid chromatography, liquid chromatography/mass spectrometry, and nuclear magnetic resonance confirmed the presence of an epoxide functional group on the metabolites. Epoxide formation as the initial activation step of aromatic compounds by oxygenases has been reported to occur only by eukaryotic monooxygenases. To the best of our knowledge, biphenyl dioxygenase from P. pseudoalcaligenes KF707 is the first prokaryotic enzyme detected that can produce an epoxide derivative on the aromatic ring structure of flavanone.

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“…Methylation reactions employing mesophilic microbes viz. Cunninghamella elegans, Streptomyces griseus, and Bruveria was reported by Park et al [19], Hosny et al [20], and Costa et al [21]. Biological activity studies of this metabolite are to be performed.…”

Section: Resultsmentioning

confidence: 94%

Potential of Thermophilic Fungus Rhizomucor pusillus NRRL 28626 in Biotransformation of Antihelmintic Drug Albendazole

Prasad

Girisham

Reddy

2011

Appl Biochem Biotechnol

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In the present investigation, thermophilic fungus Rhizomucor pusillus was used to study biotransformation of antihelmintic drug albendazole to produce its active metabolite, albendazole sulfoxide and novel metabolites of commercial interest. A two-stage fermentation procedure was followed for biotransformation of albendazole. The transformation was identified and structures were confirmed by high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry analysis. Four metabolites albendazole sulfoxide, the active metabolite, albendazole sulfone, N-methyl metabolite of albendazole sulfoxide, and a novel metabolite were produced. The study demonstrates the biotransformation ability of thermophilic fungus R. pusillus NRRL28626 in the production of, the active metabolite of albendazole which has industrial and economic importance, other metabolites and a novel metabolite in an ecofriendly way.

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Hydroxylations and Methylations of Quercetin, Fisetin, and Catechin byStreptomycesgriseus

Cited by 52 publications

References 44 publications

Effects of Hydroxy and Methoxy Substituents on NMR Data in Flavonols

Effects of Hydroxy and Methoxy Substituents on NMR Data in Flavonols

Epoxide Formation on the Aromatic B Ring of Flavanone by Biphenyl Dioxygenase of Pseudomonas pseudoalcaligenes KF707

Potential of Thermophilic Fungus Rhizomucor pusillus NRRL 28626 in Biotransformation of Antihelmintic Drug Albendazole

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