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A metabolic study has been conducted to investigate the conversion of pentachlorophenol(PCP) to water soluble metabolites in soybean and rice cell suspension cultures as well as in intact rice plants. PCP in plant cells was found to be exclusively transformed into water soluble metabolites rate of the metabolic conversion of PCP in decreasing order was soybean cultures$gt;rice cultures$gt;rice plants. Also observed was that the older the age of the cultures was, the lower the conversion rate was. Glucose conjugates isolated from both the 5 day old soybean and 8 day old rice cells were specifically hydrolyzed only by β-glucose is the glycon of the conjugates. This suggestion was further supported by the identification of glucose as a major polar product of the hydrolysis of the conjugates. In addition, the aglycons were identified as PCP, isomeric mixtures of tetrachlorophenol, and tetrachlorocatechol. The glucose conjugates and their acetylated derivatives were separated by HPLC into three fractions, that apparently contained three types of PCP-derived aglycons as mentioned above. FAB-MS analysis of each derivatives revealed that, at least in two fractions, the locations of the spectral peaks are practically coincident with those deducible from the structures of pentachlorophenyl and tetrachlorphenyl β-D-glucopyranosides. It is concluded that PCP is primarilly metabolized to glucose conjugates, which accounts for more than 50% recovery of the PCP-converged radioactivity from the water soluble metabolites: The conjugates were mainly made up of pentachlorophenyl β-D-glucopyranoside, tetrachlorophenyl β-D-glucopyranosides, and 2-hydroxy-3,4,5, 6-tetrachlorophenyt β-D-glucopyranoside.
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