Hydroxylation of reichstein's compound s with cell-free preparations from Curvularia lunata

Zuidweg, M.H.J.

doi:10.1016/0005-2760(68)90016-7

Cited by 42 publications

(7 citation statements)

References 46 publications

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“…The increased amounts of cortisol may be due to either increased 1 lp-hydroxylase activity or lower 1 -dehydrogenase activity. Our findings are consistent with the report that 1 lp-hydroxylase activity on Reichstein's compound S is unaffected by ATP and is NADPH dependent (Zuidweg 1968;Hansich and Dunnill 1980). It was also suggested that microbial hydroxylases are mixed-function oxidases using molecular oxygen and requiring an electron transport system linked to NADPHdependent dehydrogenases (Berg et al 1975(Berg et al , 1976(Berg et al , 1979Hundnik-Plevnik 1977a, 1977b …”

Section: Effect Of Some Enzyme Activatorssupporting

confidence: 91%

Some nutritional requirements of a mixed culture transforming Reichstein's compound S into prednisolone

Ghanem

Yusef²

1992

Can. J. Microbiol.

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Reichstein's compound S was successfully converted to prednisolone in a single-step fermentation using a mixed culture of Curvularia lunata and Mycobacterium smegmatis. Introducing additional medium at the time of bacterial inoculation and increasing the M. smegmatis inoculum to 8% were necessary for maximal dehydrogenation of cortisol to prednisolone (86%). However, beef extract, corn-steep solids, and malt extract were inhibitory to the dehydrogenase activity and stimulatory to hydroxylase. Of the vitamins tested, nicotinic acid and riboflavin at 0.2 and 1.13 mg/L, respectively, resulted in maximum transformation of Reichstein's compound S (100%) and optimized prednisolone yields (92%) in the mixed culture. The trace elements present in the medium were sufficient for maximal transformation, and there was no need for an exogenous supply. Addition of ATP, sodium acetate, and NAD inhibited the dehydrogenation reaction.

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Section: Effect Of Some Enzyme Activatorssupporting

confidence: 91%

Some nutritional requirements of a mixed culture transforming Reichstein's compound S into prednisolone

Ghanem

Yusef²

1992

Can. J. Microbiol.

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“…EDTA has been used in most studies of the hydroxylation of steroids by extracts of micro-organisms (Zuidweg et al, 1962;Chang & Sih, 1964;Zuidweg, 1968;Sallam et al, 1971 ;El-Kady & Allam, 1973). The effect of different concentrations of this compound on the 6P-hydroxylating activity was tested.…”

Section: Results a N D Discussionmentioning

confidence: 99%

6 -Hydroxylation of Steroids by Extracts of Aspergillus niger

El-Kady¹

1982

Microbiology

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2511Growing cultures of Aspergillus niger hydroxylate progesterone at the 6P and 1 l a positions. The properties of the 6p-hydroxylase activity were studied in extracts of this organism using llahydroxyprogesterone as substrate. Maximum 6P-hydroxylase activity was obtained at pH 6.5. EDTA and thiophenol inhibited hydroxylation, while NADPH, 2-oxoglutarate and pyruvate stimulated it. Cobalt and cadmium ions inhibited the 6P-hydroxylase activity. The feasibility of introducing a hydroxyl group into the 6P-position of various steroid compounds was tested : the 3-0X0-A4 configuration appeared to exert a directional effect for 6p-hydroxylation, while an 118-hydroxyl group exerted some kind of steric hindrance against 6p-hydroxylation.

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“…4-hydroxy phenylbutazone, previously described by E. PAWELCZYK and R. WACHOWIAK (8) reporting on conservation studies of injectable solutions of phenylbutazone, and others (15,16,17) has been demonstrated in many papers to be a degradation product (air oxidation). The interpretation of the transformation observed with R. arrhizus, was therefore not clear.…”

Section: Discussionmentioning

confidence: 99%

“…The mycelium was filtered through cheesecloth, extensively washed with NaCl 0.5% solution, then dried on a Buchner funnel and resuspended in the minimum of buffer pH 7.1 according to ZWIDWEG (8). It was then ground with a motor-driven Potter-EIvehjem homogenator at 4°C.…”

Section: Crude Homogenate Preparationmentioning

confidence: 99%

Microbiological transformation of 1,2-diphenyl-3,5 dioxo-4-n-butyl pyrazolidine (phenylbutazone)

Favero

Winternitz

1980

European Journal of Drug Metabolism and Pharmacokinetics

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Microbiological conversion of phenylbutazone with Rhizopus arrhizus Fischer gave 4-hydroxy phenylbutazone in excellent yield. Spectral studies, mass spectrometry, in particular, were made of the obtained metabolite; other experiments performed with the intact microorganism or with the cell-free system, as well as studies with the well-known metabolic inhibitor, SKF 525 A, indicated that the obtained 4-hydroxy phenylbutazone was not an artefact. Similar experiments were performed on oxyphenbutazone.

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Hydroxylation of reichstein's compound s with cell-free preparations from Curvularia lunata

Cited by 42 publications

References 46 publications

Some nutritional requirements of a mixed culture transforming Reichstein's compound S into prednisolone

Some nutritional requirements of a mixed culture transforming Reichstein's compound S into prednisolone

6 -Hydroxylation of Steroids by Extracts of Aspergillus niger

Microbiological transformation of 1,2-diphenyl-3,5 dioxo-4-n-butyl pyrazolidine (phenylbutazone)

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