Steroid hormones, eliminative reactions

Vitamin Be has a central role in the metabolism of amino acids in transaminase reactions (and hence the interconversion and catabolism of amino acids and the synthesis of nonessential amino acids), in decarboxylation to yield biologically active amines, and in a variety of elimination and replacement reactions. It is also the cofactor for glycogen phosphorylase and a variety of other enzymes. In addition, pyridoxal phosphate, the metabolically active vitamer, has a role in the modulation of steroid hormone action and the regulation of gene expression. 

Fiq. 4. Major eliminative reactions of steroid hormones and their metabolites. Hydroxylation reactions of biosynthetic tissues are not included, although they may be partly responsible for some of the observed metabolic transformations of ... 

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