11α-hydroxylation of progesterone by cell free preparation of Aspergillus ochraceus TS

Ghosh, Dipak; Samanta, Timir B.

doi:10.1016/0022-4731(81)90217-x

Cited by 35 publications

(11 citation statements)

References 19 publications

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“…Neither laccase nor cytochrome P450 activities could be demonstrated in cell-free extracts. All efforts to detect cytochrome P450 in cell extracts of A. alliaceus using metyrapone difference-dithionite reduced cytochrome P450 spectra , were also unsuccessful. Peroxidase (4 U/mg protein) and tyrosinase (0.026 U/mg protein) activities were detected in cell-free extracts.…”

Section: Resultsmentioning

confidence: 99%

Microbial Transformations of Chalcones: Hydroxylation, O-Demethylation, and Cyclization to Flavanones

Sánchez-González

Rosazza

2004

J. Nat. Prod.

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Microorganisms were examined for their potential to catalyze biotransformation reactions that mimic plant biosynthetic processes. Specifically, microorganisms were screened for their abilities to transform selected chalcones to flavonoid and other products. Aspergillus alliaceus UI 315 efficiently transformed 3-(2' ',3' '-dimethoxyphenyl)-1-(2'-hydroxyphenyl)propenone (2'-hydroxy-2,3-dimethoxychalcone) (1) to several products, all of which were characterized by UV, NMR, and mass spectral analyses. A. alliaceus cyclized 1 to three flavanones and to O-demethylated and hydroxylated chalcones, some of which functioned as intermediates in the cyclization process. Inhibition studies using SKF525A, metyrapone, and phenylthiocarbamide with whole cell reactions showed that as many as three cytochrome P450 enzymes may be involved in these reactions. One enzyme catalyzed chalcone cyclization; another, O-demethylation; and a third, hydroxylation of chalcones. Flavonoid products are racemic, unlike the same products that are stereoselectively cyclized in plants. This work shows that microorganisms are capable of cyclizing chalcones to form flavonoid products, thus affording a mimic of plant biosynthetic processes.

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Section: Resultsmentioning

confidence: 99%

Microbial Transformations of Chalcones: Hydroxylation, O-Demethylation, and Cyclization to Flavanones

Sánchez-González

Rosazza

2004

J. Nat. Prod.

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“…A cytochrome P-450 linked monooxygenase catalyzed 11α-hydroxylation of progesterone in Aspergillus ochraceus TS. The different classical inducers of cytochrome P-450 induce the benzo(a)pyrene hydroxylase activity to varying degree and suggests the existence of multiple forms of cytochrome P-450 in this fungus [9][10] . The present paper reports the presence of standard cytochrome P-450 mediated biotransformation enzymes cytochrome c reductase and hexane oxidase in Aspergillus ochraceus (NCIM 1146), and their inducible nature by using various inducers.…”

Section: Introductionmentioning

confidence: 85%

Study of mixed function oxidase system in Aspergillus ochraceus (NCIM 1146)

2007

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Aspergillus ochraceus (NCIM-1146) has shown the ability to degrade cholesterol, camphor and naphthalene, when 96 h grown mycelium incubated in medium containing these organic compounds. Presence of higher level of electron transport components and biotransformation enzyme activity were observed in Aspergillus ochraceus, when grown in potato dextrose medium for 96 h. The enzyme activity preferred NADPH as a cofactor and shows inhibition in the presence of CO, indicating cytochrome P-450 mediated reactions. A signifi cant increase in the levels of electron transport components and biotransformation enzyme activity were observed in presence of different inducers (viz. cholesterol, camphor, naphthalene, veratrole, phenobarbital, n-hexane, kerosene and saffola oil) when compared with mycelium incubated in same way with similar conditions for 2 min incubation. Analyses of the products of cholesterol and camphor using HPLC and GCMS confi rm the degradation of these compounds.

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“…2, Table 1) of progesterone is an important step in corticosteroid synthesis [38], and the biotransformation has been studied since 1950s [39]. Many microbial strains, such as Rhizopus nigricans and Aspergillus ochraceus [40,41], have been reported to be able to catalyze this conversion. However, the enzyme responsible for 11α-hydroxylation in Rhizopus was not discovered until 2010 [42].…”

Section: Steroid Bioproduction In Yeast Through Biotransformationmentioning

confidence: 99%

Yeast as a promising heterologous host for steroid bioproduction

2020

Journal of Industrial Microbiology and Biotechnology

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With the rapid development of synthetic biology and metabolic engineering technologies, yeast has been generally considered as promising hosts for the bioproduction of secondary metabolites. Sterols are essential components of cell membrane, and are the precursors for the biosynthesis of steroid hormones, signaling molecules, and defense molecules in the higher eukaryotes, which are of pharmaceutical and agricultural significance. In this mini-review, we summarize the recent engineering efforts of using yeast to synthesize various steroids, and discuss the structural diversity that the current steroidproducing yeast can achieve, the challenge and the potential of using yeast as the bioproduction platform of various steroids from higher eukaryotes.

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11α-hydroxylation of progesterone by cell free preparation of Aspergillus ochraceus TS

Cited by 35 publications

References 19 publications

Microbial Transformations of Chalcones: Hydroxylation, O-Demethylation, and Cyclization to Flavanones

Microbial Transformations of Chalcones: Hydroxylation, O-Demethylation, and Cyclization to Flavanones

Study of mixed function oxidase system in Aspergillus ochraceus (NCIM 1146)

Yeast as a promising heterologous host for steroid bioproduction

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