Synthetic Selenium Analogues of Sulfur-Containing Natural Products

1 Synthetic Selenium Analogues of Sulfur-Containing Natural Products 

As discussed in a previous section, organoselenium chemistry has recently evolved into an area which is rich and varied. Synthetic organic chemists have been instrumental in stimulating the interest in research concerning selenium analogues of natural products which contain sulfur. The biological activity of many of these molecules has also been an area of growing interest. 

A second well-known sulfur-containing coenzyme is biotin Biotin, a member of the B vitamin complex, plays an essential nutritional role in carboxylation reactions. It is the coenzyme of carboxylases and catalyzes fundamental metabolic processes. Its relative unavailability from natural sources spurred great interest in synthetic approaches, the most recent of which appeared in xhe synthesis of 

In certain ferredoxins (2 Fe-2 S) substitution of selenium for all or part of the sulfur has been accomplished and the proteins were found to be biologically active . Another notable example involved the preparation of selenated tRNA by transformation of the 4-thiouridine moiety into 4-selenouridine This was accomplished by treatment of the tRNA(-SH) with cyanogen bromide followed by conversion of the resulting tRNA-(-SCN) to tRNA(-SeH) v th NaHSe. This allows the production of significant amounts of seleno-tRNA but biological effects have not yet been reported. 

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