Difference of the liver and kidney in glycine conjugation of ortho-substituted benzoic acids

The relative importance of the liver and kidney for glycine conjugation of ortho-substituted benzoic acids was investigated. Glycine conjugation of ortho-substituted benzoic acids was investigated in mouse liver and kidney mitochondria. The extent of glycine conjugation of benzoic acids with the halogen group decreased in the order F > Cl > Br > I. The conjugation of salicylic acid with glycine took place in only the kidney. 2-Methoxybenzoic acid exhibited no activity in the liver and kidney. The difference in glycine conjugation of ortho-substituted benzoic acids was observed between liver and kidney. The kidney was more active in glycine conjugation of ortho-substituted acids than the liver. In addition, the relationship between glycine conjugation and the chemical structure of ortho-substituted acids was examined in the liver and kidney. The size of the substituent had a far greater influence over glycine conjugation in the liver and kidney. Glycine conjugation was also dependent on the substituent electronegativity. It may be important that the substrates undergoing glycine conjugation contain a flat region coplanar to the carboxylate group.