- The desA and desB genes from Clostridium scindens ATCC 35704 encode steroid-17,20-desmolase
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Clostridium scindens is a gut microbe capable of removing the side-chain of cortisol, forming 11?-hydroxyandrostenedione. A cortisol-inducible operon (desABCD) was previously identified in C. scindens ATCC 35704 by RNA-Seq. The desC gene was shown to encode a cortisol 20?-hydroxysteroid dehydrogenase (20?-HSDH). The desD encodes a protein annotated as a member of the major facilitator family, predicted to function as a cortisol transporter. The desA and desB genes are annotated as N-terminal and C-terminal transketolases, respectively. We hypothesized that the DesAB forms a complex and has steroid-17,20-desmolase activity. We cloned the desA and desB genes from C. scindens ATCC 35704 in pETDuet for overexpression in Escherichia coli. The purified recombinant DesAB was determined to be a 142 ± 5.4 kDa heterotetramer. We developed an enzyme-linked continuous spectrophotometric assay to quantify steroid- 17,20-desmolase. This was achieved by coupling DesABdependent formation of 11?-hydroxyandrostenedione with the NADPH-dependent reduction of the steroid 17-keto group by a recombinant 17?-HSDH from the filamentous fungus, Cochliobolus lunatus. The pH optimum for the coupled assay was 7.0 and kinetic constants using cortisol as substrate were Km of 4.96 ± 0.57 μM and kcat of 0.87 ± 0.076 min?1. Substrate- specificity studies revealed that rDesAB recognized substrates regardless of 11?-hydroxylation, but had an absolute requirement for 17,21-dihydroxy 20-ketosteroids.- Devendran, S., S. M. Mythen, and J. M. Ridlon. The desA and desB genes from Clostridium scindens ATCC 35704 encode steroid-17,20-desmolase.
- Devendran, Saravanan,Mythen, Sean M.,Ridlon, Jason M.
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p. 1005 - 1014
(2018/06/22)
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- C-20 ketone reduction of hydrocortisone by rice field microalga Chlorella vulgaris MCCS 013
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A unicellular microalga, Chlorella vulgaris, was isolated from rice field and applied in the biotransformation experiment of hydrocortisone (1). This strain has not been previously tested for hydrocortisone bioconversion. Fermentation was carried out in B
- Ghasemi, Younes,Rasoul-Amini, Sara,Morowvat, Mohammad Hossein,Ghoshoon, Mohammad Bagher,Raee, Mohammad Javad,Khoubani, Soraya,Negintaji, Narges,Nouri, Fatemeh,Parvizi, Rezvan
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experimental part
p. 824 - 828
(2010/08/19)
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- Biotransformation of hydrocortisone by a natural isolate of Nostoc muscorum
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Hydrocortisone was converted in the culture of an isolated strain of the cyanobacterium Nostoc muscorum PTCC 1636 into some androstane and pregnane derivatives. The microorganism was isolated during a screening program from soil samples collected from paddy fields of north of Iran. The bioproducts obtained were purified using chromatographic methods and identified as 11β-hydroxytestosterone, 11β-hydroxyandrost-4-en-3,17-dione and 11β,17α,20β,21-tetrahydroxypregn-4-en-3-one on the basis of their spectroscopic features.
- Yazdi, Mojtaba Tabatabaei,Arabi, Homeira,Faramarzi, Mohammad Ali,Ghasemi, Younes,Amini, Mohsen,Shokravi, Shadman,Mohseni, Farzaneh Aziz
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p. 2205 - 2209
(2007/10/03)
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- 5β-cyano-substituted steroid compounds
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Novel 5β-cyano steroid compounds including compounds of Formula VII: wherein A—A, B—B, R3, R8and R9are as defined in the specification.
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- Photochemical Studies, 64. - Photostability of Glucocorticoids in the Solid State
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Most of the pharmacopoeia require that the glucocorticoids hydrocortisone (1), cortisone (2), hydrocortisone 21-acetate (3) and cortisone 21-acetate (4) must be protected from light during storage.The present study shows that irradiation of these compounds in the solid state leads to the loss of the side chain at C-17.Two-17-ketosteroids, 11β-hydroxy-4-androstene-3,17-dione (6) and 4-androstene-3,11,17-trione (7), were obtained as photoproducts (yields 3percent and 4percent, respectively).Key Words: Hydrocortisone / Cortisone / Steroids / Photochemistry
- Reisch, Johannes,Iranshahi, Lotfollah,Ekiz-Guecer, Nurten
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p. 1199 - 1200
(2007/10/02)
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- Radiolytic degradation scheme for 60Co-irradiated corticosteroids
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The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.
- Kane,Tsuji
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- 17-KETOSTEROIDS VIA A BASE INDUCED CLEAVAGE OF C-17-DIHYDROXY ACETONE SIDE CHAINS
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A new, base-catalyzed cleavage of C21-steroids to give 17-ketosteroids is described.This reaction is specific for those steroids containing the C-17-dihydroxy acetone side chain.In the presence of oxygen, these same reaction conditions readily degrade corticosterone to the 17β-carboxylic acid.
- Simons, S. Stoney,Merchlinsky, Michael J.,Johnson, David F.
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p. 281 - 290
(2007/10/02)
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