BIOTRANSFORMATION OF ORGANIC SULFIDES .8. A PREDICTIVE MODEL FOR SULFOXIDATION BY HELMINTHOSPORIUM SPECIES NRRL-4671

The fungus Helminthosporium species NRRL 4671 converts a wide range of prochiral sulfides to the corresponding chiral sulfoxides, the majori ty of which have (S) configuration at sulfur. The formation of a serie s of chiral cyclopentyl alkyl, cyclohexyl alkyl, benzyl alkyl, and met hyl alkyl sulfoxides by biotransformation of the corresponding sulfide s using Helminthosporium species is described. The analysis of over 90 such biotransformations has resulted in the development of a model ba sed on restrictive space descriptors that has been used to rationalize these reactions, and that is proposed as a predictor of the outcome o f Helminthosporium-catalyzed sulfoxidations. (C) 1997 Elsevier Science Ltd.