title: Interactions of heterocyclic Maillard products with the hepatic microsomal monooxygenase system.
abstract: 1. Interactions of methyl-substituted pyrazines, and other constituents of Maillard products generated during heat treatment of food, with hepatic microsomal mixed-function oxygenases were studied in vitro. 2. Spectral interactions of N-containing heteroaromatic compounds with the cytochrome P-450 system are type I or type II depending on the state of induction, and are relatively weak. Inhibition of 7-ethoxycoumarin O-deethylation by these compounds is ten times lower than that of metyrapone, agreeing with the weak spectral interaction. Inhibition is competitive for 2,3-dimethylquinoxaline, and complex for 2,5-dimethylpyrazine and 2,3,5,6-tetramethylpyrazine. 3. Spectral and inhibitory interactions indicate biotransformation. This was studied with 2,3,5,6-tetramethylpyrazine; the metabolite formed was identified as 2-hydroxymethyl-3,5,6-trimethylpyrazine. Metabolism to the N-oxide did not occur.
authors.affiliation: Department of Pharmacology and Toxicology, Philipps-University Marburg, FRG.
authors.forename: B
authors.initials: B
authors.lastname: Hahnemann
authors.forename: W
authors.initials: W
authors.lastname: Legrum
authors.forename: G
authors.initials: G
authors.lastname: Koss
authors.forename: K J
authors.initials: KJ
authors.lastname: Netter
mesh_terms: D015660:7-Alkoxycoumarin O-Dealkylase / Q000037:antagonists & inhibitors; D000818:Animals; D001711:Biotransformation; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005421:Flavoring Agents / Q000378:metabolism / Q000494:pharmacology; D015416:Maillard Reaction; D008297:Male; D051379:Mice; D008862:Microsomes, Liver / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D013057:Spectrum Analysis
chemical_list: D005421:Flavoring Agents; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D015660:7-Alkoxycoumarin O-Dealkylase