Steroid Transformafions 127 



OXYGENATION OF STEROIDS BY INTRODUCTION OF A 

 HYDROXYL OR KETONE GROUP ON THE NUCLEUS 



On the basis of some of the more extensively studied 

 microorganisms, it has been found that hydroxyl groups 

 can be introduced as follows. 



Carbon No. Orientation Microorganism 



In addition to the foregoing types of compounds, dihy- 

 droxylation has been obtained in the following combina- 

 tions, 6p,lla-; 713,11a-; 6p,17a-; and 11 a, 17a-. Cunning- 

 hamella (8, 21) and Curvularia (33) have been shown to 

 introduce an 11-keto as well as an lip-hydroxy group on 

 the steroid nucleus as in cortisone (VIII) when Reichstein's 

 compound S (XIII) is used as the substrate. 



RUPTURE OF CARBON TO CARBON LINKAGES 



Cleavage of the Side Chain. Compounds such as pro- 

 gesterone (XI), desoxycorticosterone (XIV), and Reich- 

 stein's compound S (XIII) can be converted by cleavage of 

 the side chain to 4-androstene-3,17-dione (XIX) by certain 

 species of Gliocladium (28), Penicillium (28), Aspergillus 

 (28), and Fusarium (35). 



The side chain of cholestenone as shown by Turfitt (34) 

 can be cleaved by a Proactinomyces to produce etiocholenic 

 acid. 



