Enzymatic method for selective determination of 4-aminobenzoic acid in urine.
We developed a method for the selective determination of 4-aminobenzoic acid by use of 4-aminobenzoate hydroxylase (EC 1.14.13.27) to convert 4-aminobenzoic acid to 4-hydroxyaniline. The subsequent conversion of 4-hydroxyaniline to indophenol dye was quantified colorimetrically. The method is reproducible, and the assay response is linear up to 40 mumol/L. Selectivity exceeding that of the current colorimetric assays was demonstrated for these enzymatic determinations of 4-aminobenzoic acid concentrations in urine samples from patients undergoing tests of pancreatic function with bentiromide. This method effectively minimizes interferences from drugs and diet, a problem in current colorimetric methods.
Bando
N
N
Department of Nutrition, School of Medicine, University of Tokushima, Japan.
Ogawa
T
T
Tsuji
H
H
Sasaoka
K
K
D010129:4-Aminobenzoic Acid / Q000378:metabolism / Q000652:urine*; D003124:Colorimetry / Q000379:methods; D006801:Humans; D006899:Mixed Function Oxygenases
D006899:Mixed Function Oxygenases; C050092:4-aminobenzoate hydroxylase; D010129:4-Aminobenzoic Acid