Analysis for nonextractable (bound) residues of pentachlorophenol in plant cells using a cell wall fractionation procedure.

When plant cell cultures or aseptically grown wheat plants were treated with [14C]-pentachlorophenol (PCP) a major part of the label was found in a nonextractable or "bound" residue fraction. Soluble polar conjugates participated in the formation of these residues which were mainly located in the plant cell walls. By a sequential fractionation procedure using enzymatic and chemical methods, 90 to 95% of the bound radioactivity could be attributed to individual cell wall components. The 14C label from PCP was found mainly in hemicellulose, lignin, and protein fractions. Associations of hemicellulose with PCP derivatives with molecular weights up to 500,000 were purified to constant specific radioactivity. Hydrolysis of this fraction released 32% PCP and other unidentified products.