- Stereospecific oxidation of 3β-hydroxysteroids by persolvent fermentation with Pseudomonas sp. ST-200
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Pseudomonas sp. strain ST-200 isolated from a humus soil effectively oxidizes cholesterol dissolved in organic solvents but not that suspended in the growth medium. The organism does not assimilate cholesterol. This organism oxidized a variety of 5α- or 5-ene-steroids dissolved in organic solvent. First, the 3β-OH group was oxidized to a ketone group. The 3α-OH group was scarcely oxidized. Successively, C-6 position of 5-ene-steroids was hydroxylated, and a double bond of 5-ene-steroids was transferred from Δ5 to Δ4. Then, the 6-OH group was oxidized to a ketone group. Persolvent fermentation with ST-200 would provide an effective, convenient, and stereospecific method to oxidize the C-3 and C-6 positions of steroids.
- Aono, Rikizo,Doukyu, Noriyuki
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p. 1146 - 1151
(2007/10/03)
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- THE OXIDATION OF PROGESTERONE UNDER GoAggIII CONDITIONS
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The oxidation of pregn-4-ene-3,20-dione (progesterone) by the GoAggIII system (aqueous hydrogen peroxide, ferric chloride, picolinic acid in pyridine-acetic acid solution) has been investigated.Two tri-keto derivatives were isolated and identified as pregn-4-ene-3,6,20-trione and pregn-4-ene-3,12,20-trione.The third major product isolated was identified as the unstable 5α-formyl-A-nor-pregnane-3,20-dione, which deformylated spontaneously to A-nor-5β-pregnane-3,20-dione.A mechanism for the A-ring contraction is proposed, based upon the participation of a carbon-Fe(V) intermediate.
- Barton, Derek H. R.,Doller, Dario
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p. 984 - 990
(2007/10/02)
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