Steroid Transformafions 



125 



tained by Hanson et al. (8), employing Cunninghamella, 

 and later by Shull et al. (33) using a Curvularia. Thus, 

 in contrast to the many steps required by the chemist to 

 introduce the important 11 -oxygen atom, certain fungi 

 produce 11 -oxygenated steroids in a one-step process from 

 readily available steroidal substrates having no special fea- 

 tures in the 11 or 12 positions. 



Compound XII (lla-hydroxyprogesterone) can be 

 readily and economically converted to cortisone (VIII) 

 (15, 26) or hydrocortisone (IX) (13). 



Extensive work by our laboratories (3, 21, 30) and by 

 Fried et al. (5) showed that many different substrates could 

 be oxygenated not only at carbon 11 but also in other 

 nuclear positions. 



IX 



Hydrocortisone 



Next to the 11 -oxygen function, the 17a-hydroxyl group 

 of the adrenal hormones is the most difficult to introduce 

 chemically, particularly in the presence of a 3-keto-A*- 

 system. We have recently found that the mold Cephalothe- 

 cium (20) can hydroxylate steroids in this position. This is 

 the first report of 17-hydroxylation of steroids by micro- 

 organisms. Other hydroxylating enzymes, 6(3- and 11a-, for 

 example, are also produced by this mold, so that from a 

 single fermentation various combinations of dihydroxyl- 



