Isolation and identification of a novel aromatic amine mutagen produced by the Maillard reaction.

To clarify the formation of mutagens in the Maillard reaction of glucose and amino acids, 20 amino acids were separately incubated with glucose in the presence or absence of hydroxyl radicals produced by the Fenton reaction. After 1 week at 37 degrees C and pH 7.4, the reaction mixtures of glucose and tryptophan with and without the Fenton reagent showed mutagenicity toward Salmonella typhimurium YG1024 in the presence of a mammalian metabolic system (S9 mix). To identify mutagens in the reaction mixture, blue rayon-adsorbed material from a mixture of glucose, tryptophan, and the Fenton reagent was separated by column chromatography using various solid and mobile phases, and one mutagen, which accounted for 18% of the total mutagenicity of the reaction mixture, was isolated. The chemical structure of the mutagen was determined to be 5-amino-6-hydroxy-8H-benzo[6,7]azepino[5,4,3-de]quinolin-7-one (ABAQ) on the basis of ESI mass, high-resolution APCI mass, (1)H NMR, (13)C NMR, and IR spectral analyses and chemical synthesis of the mutagen. The novel aromatic amine showed high mutagenicity toward S. typhimurium TA98 and YG1024 with S9 mix, inducing 857 revertants of TA98 and 6007 revertants of YG1024/microg, respectively. The mutagenicity of ABAQ was comparable to that of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, which is a mutagenic and carcinogenic hetrocyclic amine in cooked meat and fish formed through the Maillard reaction at high temperature.

Determination of a pyrimido-benzazepine anxiolytic agent and its 5-hydroxy metabolite in whole blood, plasma and urine by gas--liquid chromatography with electron-capture detection and by high-performance liquid chromatography.

Electron-capture gas--liquid chromatographic and reversed-phase high-performance liquid chromatographic assays are described for the quantitation of the compound, 9-chloro-7-(2-chlorophenyl)-5H-pyrimido [5,4-d] [2]-benzazepine, [I], a member of the benzazepine class of compounds undergoing clinical evaluation as anxiolytic agents. Studies on the biotransformation of [I] in the rat and dog showed that the compound was metabolized mainly by hydroxylation to yield the 5-hydroxy compound, [II], 9-chloro-7-(2-chlorophenyl)-5H-pyrimido [5,4-d] [2]-benzazepin-5-ol (major metabolite), along with the formation of lesser amounts of the N-oxide, [III], 9-chloro-7-(2-chlorophenyl)-5H-pyrimido [5,4-d] [2]-benzazepine 3-oxide, and the phenolic analogue, [IV], 3-chloro-4-(9-chloro-5H pyrimido-[5,4-d] [2] benzazepin-7-yl)phenol. This report describes the quantitation of [I] and [II] (major metabolite) in plasma using the above analytical techniques, both in preclinical studies in the dog and in clinical pharmacokinetic studies in man.