Dehydrogenation microbiological

A vast amount of research resulted in the improvement of this bioconversion, as well as the development of many other microbiological reactions. Some of these include Ci-dehydrogenation, C 6-a-hydroxylation, and Cj i-P-hydroxylation of steroids [45-52]. Other... 

Many more active compounds such as prednisone, prednisolone and several fluorosteroids have been introduced involving microbiological dehydrogenation at the 1-position in the first two and in the majority of compounds, the use of semi-synthetic routes. 

Triamcinolone (I, Figure 6) is most commonly synthesized by microbiological dehydrogenation at C-1,2 of 16a-hydroxy-9a-fluorohydrocortisone (II) directly or with intermediate formation of the 16,17-borate ester or 16,21-diacetate (V). A variety of microbiological organisms, capable of 1-dehydrogenation have been reported- - or patented... 

Triamcinolone (I) diacetate has been prepared by microbiological or selenium dioxide dehydrogenation at C-1,2 of 16a-hydroxy-9a-fluoro-... 

This microbiologically selective dehydrogenation of 10/ -chiral A -3-ketones appears to be quite general, and has been applied to 10a-testosterone and a number of di-, tri-, and tetra-cyclic compounds containing both five- and six-membered rings. 

A third advancement in microbial biotechnology of steroid production was the ability to introduce a 16(X-hydroxyl group microbiologically (163). Modifications of the liP-hydroxylation, 16ct-hydroxylation 1,2-dehydrogenation microbial processes are used for the synthesis of hydrocortisone, prednisolone, triamcinolone, and other steroid pharmaceuticals. A few microbial transformations that have been used to manufacture steroids are listed in Table 1 (164). 

Prednisone may be prepared from cortisone by a highly specific microbiological process using Corynebacterium simplex, that selectively dehydrogenates cortisone at the C-1 and C-2 positions. 

Microbiological Method Prednisolone is prepared by the microbiological method starting with hydrocortisone using Corynebacterium simplex, which strategically and selectively causes dehydrogenation of the initial product at C-1 and C-2 positions. 

These proposals are very satisfying in many ways. An obstacle, however, to the extension of the proposed mechanism to aU microbiological dehydrogenation of 3-ketosteroids at the 1-position is the work of Fonken and Murray (F-253). They showed that the 20-ketal of 5/3-pregnane-3,ll,20-trione is dehydrogenated at the 1-position by Septomyxa affinis. Either the illustrated 3-keto-5 -pregnane (I) enolizes abnormally... 

Prednisolone 1,2-dehydrocortisol, 11, 17a,21-trihydroxy pregna-l,4-diene-3,20-dione, a synthetic steroid prepared by chemical or microbiological dehydrogenation of cortisol. It has powerful antiinflanunatoiy and antiallergic activity, very similar to that of prednisone (1,2-dehydrocortisone, the corresponding dehydro derivative of cortisone) both compounds are used in the treatment of disorders such as asthma, arthritis and eczema. 

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