Semi-Synthesis of Corticosteroids

Some steroid drugs are produced by total synthesis, but, in general, the ability of microorganisms to biotransform steroid substrates has proved invaluable in exploiting inexpensive natural steroids as sources of drug materials. It is now possible via microbial fermentation to hydroxylate the steroid nucleus at virtually any position and with defined stereochemistry. These 

Mineralocorticoids are primarily of value in maintaining electrolyte balance where there is adrenal insufficiency. 

The aromatic ring makes the oestrogen molecule almost planar (see page 233) and is essential for activity. Changes which remove the aromaticity, e.g. partial reduction, or alter stereochemistry, give analogues with reduced or no activity. 

It is particularly worthy of note that the routes to corticosteroids, progestogens, oestro-gens, and androgens involve common precursors or partial pathways. This means that these processes need to be under very tight control if 

The ratio of androgenic to anabolic activity can vary in different molecules. There have been attempts to produce steroids with low androgenic but high anabolic activity to use for various 

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