Metabolites of 4-n-Nonylphenol in Wheat Cell Suspension Cultures

4-Nonylphenol, a metabolite of nonionic surfactants, was examined for its metabolism in cell cultures of wheat according to a standardized method. Four major radioactively labeled fractions were detected and isolated by chromatography on Sephadex LH-20 and semipreparative HPLC. Hydrolysis of the peaks resulted in two compounds which were purified by semipreparative HPLC. Using enzymatic hydrolysis, HPLC, GC−MS, and ESI-MS/MS, the chemical structures were elucidated. They were shown to be 4-(hydroxy)- and 4-(dihydroxy)nonylphenols which were glucosylated at the phenolic OH-group and further glucosylated, glucuronidated, and acylated with acetic acid or malonic acid. Except for C-1 and C-9, the hydroxylations occurred at all C atoms of the alkyl side chain. Keywords: Alkylphenol; nonionic surfactant; plant metabolism; Triticum aestivum; electrospray mass spectrometry; xenobiotics