Degradation of a nonylphenol single isomer by Sphingomonas sp. strain TTNP3 leads to a hydroxylation-induced migration product

Abstract

Sphingomonas sp. strain TTNP3 degrades 4(3',5'-dimethyl-3'-heptyl)-phenol and unidentified metabolites that were described previously. The chromatographic analyses of the synthesized reference compound and the metabolites led to their identification as 2(3',5'-dimethyl-3'-heptyl)-1,4-benzenediol. This finding indicates that the nonylphenol metabolism of this bacterium involves unconventional degradation pathways where an NIH shift mechanism occurs.

FIG. 1.

Chemical structure of 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) (a), 4(3′,5′-dimethyl-3′-heptyl)-catechol (b), 4(3′,5′-dimethyl-3′-heptyl)-resorcinol (c), and 2(3′,5′-dimethyl-3′-heptyl)-1,4-benzenediol (o353NHQ) (d). Also shown is the schematic presentation of the reaction pathway proposed for the formation of NIH-shifted metabolites of p353NP (a through d).

FIG. 2.

GC-MS/MS-SRM spectra of trimethylsilylated derivates of the reference compound 2(3′,5′-dimethyl-3′-heptyl)-1,4-benzenediol (o353NHQ) (A and B) and of metabolites of 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) (C and D). (A and C) transition 380⁺→309⁺, MS²; (B and D) transition 309⁺→267⁺, MS³.