1224-07-3Relevant academic research and scientific papers
Hydroxylation of steroids by Fusarium oxysporum, Exophiala jeanselmei and Ceratocystis paradoxa
Peart, Patrice C.,McCook, Kayanne P.,Russell, Floyd A.,Reynolds, William F.,Reese, Paul B.
, p. 1317 - 1330 (2011)
The potential of Fusarium oxysporum var. cubense UAMH 9013 to perform steroid biotransformations was reinvestigated using single phase and pulse feed conditions. The following natural steroids served as substrates: dehydroepiandrosterone (1), pregnenolone (2), testosterone (3), progesterone (4), cortisone (5), prednisone (6), estrone (7) and sarsasapogenin (8). The results showed the possible presence of C-7 and C-15 hydroxylase enzymes. This hypothesis was explored using three synthetic androstanes: androstane-3,17-dione (9), androsta-4,6-diene-3,17-dione (10) and 3α,5α-cycloandrost-6- en-17-one (11). These fermentations of non-natural steroids showed that C-7 hydroxylation was as a result of that position being allylic. The evidence also pointed towards the presence of a C-15 hydroxylase enzyme. The eleven steroids were also fed to Exophiala jeanselmei var. lecanii-corni UAMH 8783. The results showed that the fungus appears to have very active 5α and 14α-hydroxylase enzymes, and is also capable of carrying out allylic oxidations. Ceratocystis paradoxa UAMH 8784 was grown in the presence of the above-mentioned steroids. The results showed that monooxygenases which effect allylic hydroxylation and Baeyer-Villiger rearrangement were active. However, redox reactions predominated.
The scope and limitations of the reaction of Δ5-steroids with mercury(II) trifluoroacetate
Ruddock, Peter L.D.,Williams, David J.,Reese, Paul B.
, p. 650 - 664 (2007/10/03)
The effect of the C-3 substituent on the reaction of androst-5-enes with mercury(II) trifluoroacetate in dichloromethane (modified Treibs oxidation) was investigated. 3β-Acyloxyandrost-5-en-17-ones gave 3β-acyloxy-6β- hydroxyandrost-4-en-17-ones accompanied by 3β-acyloxy-6- chloromercuriandrost-5-en-17-ones. 3β-Acetoxy-6β-trifluoroacetoxyandrost- 4-en-17-one and 3β-acetoxy-4β-trifluoroacetoxyandrost-5-en-17-one were revealed to be intermediates in the reaction. The formation of the chloromercury steroids indicated participation in the reaction by the solvent. With 3α-acetoxyandrost-5-en-17-one as substrate, a complete reversal in the product distribution was observed. 3β-Haloandrost-5-en-17- ones gave mainly products that reflected S(N)1 substitution of the halide. 3β-Hydroxy- and 3β-trifluoroacetoxyandrost-5-en-17-ones were formed. 3β- Methoxyandrost-5-en-17-one afforded in nearly identical yields androst-4- ene-3,17-dione, 3β-methoxy-6β-hydroxyandrost-4-en-17-one, 3β-methoxy-6- chloromercuriandrost-5-en-17-one and 6β-hydroxyandrost-4-ene-3,17-dione while androst-5-en-17-one yielded 3β,6β-dihydroxyandrost-4-en-17-one, androst-5-ene-7,17-dione and androst-4-ene-3,17-dione. The effects of solvent and other mercury salts on the reaction were also studied. Treibs oxidation was successful in chloroform, carbon tetrachloride, and dibromomethane, but not in other solvents tested. 3β-Acetoxy-6-bromomercuriandrost-5-en-17-one was obtained in dibromomethane. Replacement of the reagent by mercury(II) trichloroacetate altered the intermediates formed but not the products. Mercury(II) tribromoacetate was unreactive, however.
Steroidal Allylic and Homoallylic Rearrangements during Halogenation with Triphenylphosphine and Carbon Tetrachloride
Hanson, James R.,Hitchcock, Peter B.,Reese, Paul B.,Truneh, Almaz
, p. 1469 - 1472 (2007/10/02)
Treatment of 3β-hydroxyandrost-5-en-17-one with triphenylphosphine and carbon tetrachloride under various conditions affords 3α- and 3β-chloroandrost-5-en-17-one, 3α,5-cycloandrost-6-en-17-one, and minor amounts of 17-dichloromethylene derivatives.In contrast, 4β-acetoxy-3β-hydroxyandrost-5-en-17-one affords 4β-acetoxy-3α-chloro- and 3β-acetoxy-4α-chloro-androst-5-en-17-ones. 3β-Acetoxy-4β-hydroxyandrost-5-en-17-one affords 3β-acetoxyandrost-4,6-dien-17-one and minor amounts of the 3β-acetoxy-4α-chloro-5-ene and 3β-acetoxy-6α-chloro-4-ene.
