ENANTIOMERIC COMPOSITION OF THE TRANS-DIHYDRODIOLS PRODUCED FROM PHENANTHRENE BY FUNGI

The trans-dihydrodiols produced during the metabolism of phenanthrene by Cunninghamella elegans, Syncephalastrum racemosum, and Phanerochaet e chrysosporium were purified by high-performance liquid chromatograph y (HPLC). The enantiomeric compositions and optical purities of the tr ans-dihydrodiols were determined to compare interspecific differences in the regio- and stereoselectivity of the fungal enzymes. Circular di chroism spectra of the trans-dihydrodiols were obtained, and the enant iomeric composition of each preparation was analyzed by HPLC with a ch iral stationary-phase column. The phenanthrene trans-1,2-dihydrodiol p roduced by C. elegans was a mixture of the IR,2R and IS,2S enantiomers in variable proportions. The phenanthrene trans-3,4-dihydrodiol produ ced by P. chrysosporium was the optically pure 3R,4R enantiomer, but t hat produced by S. racemosum was a 68:32 mixture of the 3R,4R and 3S,4 S enantiomers. The phenanthrene trans-9,10-dihydrodiol produced by P. chrysosporium was predominantly the 9S,10S enantiomer, but those produ ced by C. elegans and S. racemosum were predominantly the 9R,10R enant iomer. The results indicate that although different fungi may exhibit similar regioselectivity, there still may be differences in stereosele ctivity that depend on the species and the cultural conditions.