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-sterols 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 Δ 4. 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.
从腐殖土中分离得到的Pseudomonas sp. 菌株ST-200能有效氧化溶解于有机溶剂中的
胆固醇,但不能氧化悬浮于生长介质中的
胆固醇。该菌株不吸收
胆固醇,但能氧化多种溶解于有机溶剂的5α-或5-烯
甾醇。首先,将3β-OH基团氧化为酮基,而3α-OH基团几乎不被氧化。接着,5-烯甾体的C-6位进行羟基化,5-烯甾体的双键从Δ5转移到Δ4。随后,6-OH基团被氧化为酮基。利用ST-200进行溶剂发酵可提供一种有效、便捷且具有立体选择性的方法,用于
甾体化合物C-3和C-6位的氧化。