Gentisic acid and its 3- and 4-methyl-substituted homologoues as intermediates in the bacterial degradation of m-cresol, 3,5-xylenol and 2,5-xylenol

Biochem J. 1971 Mar;122(1):19-28. doi: 10.1042/bj1220019.


1. Intact cells of a non-fluorescent Pseudomonas grown with m-cresol, 2,5-xylenol, 3,5-xylenol, 3-ethyl-5-methylphenol or 2,3,5-trimethylphenol rapidly oxidized all these phenols to completion. 3-Hydroxybenzoate and 2,5-dihydroxybenzoate (gentisate) were also readily oxidized. 2. 3-Hydroxybenzoic acid and 2,5-dihydroxybenzoic acid were isolated as products of m-cresol oxidation by cells inhibited by alphaalpha'-bipyridyl. Alkyl-substituted 3-hydroxybenzoic acids and alkyl-substituted gentisic acids were formed similarly from 2,5-xylenol, 3,5-xylenol, 3-ethyl-5-methylphenol and 2,3,5-trimethylphenol. 3. When supplemented with NADH, not NADPH, extracts of cells grown with 2,5-xylenol catalysed the oxidation of all five phenols and accumulated the corresponding gentisic acids in the presence of alphaalpha'-bipyridyl. 4. Cells of a fluorescent Pseudomonas grown with m-cresol oxidized m-cresol, 3,5-xylenol and 3-ethyl-5-methylphenol to completion and oxidized 2,5-xylenol and 2,3,5-trimethylphenol partially. The oxidation product of 2,5-xylenol was identified as 3-hydroxy-4-methylbenzoic acid. In the presence of alphaalpha'-bipyridyl, 3-hydroxy-5-methylbenzoic acid and 3-methylgentisic acid were formed from 3,5-xylenol.

MeSH terms

  • Benzoates / metabolism
  • Cell-Free System
  • Chromatography, Thin Layer
  • Cresols / metabolism*
  • Gentisates / metabolism*
  • NAD / metabolism
  • Oxidation-Reduction
  • Phenols / metabolism
  • Pseudomonas / metabolism*
  • Spectrophotometry
  • Xylenes / metabolism*


  • Benzoates
  • Cresols
  • Gentisates
  • Phenols
  • Xylenes
  • NAD