Main content area

Animal bioavailability of a 3,4-dichloroaniline-lignin metabolite fraction from wheat

Sandermann, H. Jr.
Journal of agricultural and food chemistry 1992 v.40 no.10 pp. 2001-2007
Triticum aestivum, lignin, metabolites, pesticide residues, isotope labeling, carbon, radionuclides, bioavailability, solubility, ingestion, rats, lambs
Treatment of intact wheat plants and excised shoot tissues with [U-14C]-3,4-dichloroaniline led to 55-65% incorporation of the radioactivity into the 'insoluble' residue. A sequential solubilization procedure revealed that 85% of the 14C-label was associated with the operationally defined lignin fraction. When the 'insoluble' wheat metabolite residue was fed to rats and lambs, 11-20% of the bound radioactivity was released in soluble form. Refeeding the lamb fecal residue to rats released another approximately 7% of the bound radioactivity. A 3,4-dichloroaniline-lignin metabolite prepared enzymatically has previously been shown to be more extensively solubilized by rate (approximately 66%). Mild acid hydrolysis under simulated stomach conditions (0.1 N HCl, 37 degrees C) resulted in a "burst" release of free 3,4-dichloroaniline (approximately 30%) only from the previously used lignin metabolite. The presence of 4-hydroxybenzylamine linkages in only the lignin metabolites prepared enzymatically under mild conditions is proposed to explain the different degrees of solubilization in the digestive tract of animals. Animal bioavailability results can thus strongly depend on the methods used to prepare the bound" metabolite fraction.