Side chain hydroxylation of aromatic compounds by fungi: 3. Direct observation of fungal biotransformation by NMR

Abstract

The enzymatic hydroxylations by intact fungal cells at the benzylic positions of toluene- d 8 , meta-fluorotoluene-α,α,α- d 3 , para-fluorotoluene-α,α,α- d 3 , ethylbenzene-α,α- d 2 , meta-fluoroethylbenzene-α,α- d 2 , and para-fluoroethylbenzene-α,α- d 2 can be observed directly in an NMR tube by using 2H NMR as a probe. This technique provides a new method for the rapid screening of microorganisms for biotransformative capability. In all cases, the rate of product accumulation was uniform over a period of at least 4 days. The fluoro-substituted products were formed at a rate independent of the position of substitution, but slower than the corresponding unsubstituted substrates.