Three N-aralkylated derivatives of 1-aminobenzotriazole as potent and isozyme-selective, mechanism-based inhibitors of guinea pig pulmonary cytochrome P-450 in vitro

From National Research Council Canada

Link	http://dmd.aspetjournals.org/content/18/6/1031
Author	Search for: Woodcroft, K. J.; Search for: Szczepan, E. W.; Search for: Knickle, L. C.; Search for: Bend, J. R.
Format	Text, Article
Abstract	The potency and cytochrome P-450 (P-450) isozyme selectivity of 1-aminobenzotriazole (ABT) and three of its N-aralkylated analogues, N-benzyl-1-aminobenzotriazole (BBT), N-alpha-methylbenzyl-1-aminobenzotriazole (alpha MB), and the newly synthesized N-alpha-ethylbenzyl-1-aminobenzotriazole (alpha EB), as mechanism-based inhibitors were compared in pulmonary microsomes of untreated and beta-naphthoflavone (beta-NF)-induced guinea pigs. All four compounds were suicide substrates for pulmonary P-450, resulting in the loss of spectrally assayed hemoprotein (up to 50%). Monooxygenase activities were measured with isozyme-selective/specific substrates; the O-dealkylation of 7-pentoxyresorufin (PRF) for the guinea pig ortholog of rabbit P-450IIB4, the O-deethylation of 7-ethoxyresorufin for P-450IA1, and the N-hydroxylation of the aromatic amine 4-aminobiphenyl for P-450IVB1, BBT, alpha MB, and alpha EB were selective for the suicidal inhibition of P-450IIB4; for example, 1 microM alpha MB inactivated 95% of P-450IIB4-, and approximately 10% of P-450IA1- and IVB1-catalyzed, activity in microsomes from beta-NF-induced lungs. Isozyme selectivity was approximately the same for alpha EB and slightly lower for BBT, which inactivated relatively more P-450IA1. At low concentrations, 1 and 10 microM, respectively, ABT preferentially inactivated P-450IVB1, consistent with the efficient N-hydroxylation of aromatic amines by this form of P-450. alpha EB also was shown to efficiently inactivate P-450IIB4-catalyzed PRF activity in microsomes prepared from liver of phenobarbital-induced guinea pigs.
Publication date	1990-11
Publisher	American Society for Pharmacology and Experimental Therapeutics
In	Drug Metabolism and Disposition 18, no. 6: 1031–1037.
Language	English
Peer reviewed	Yes
NRC publication	This is a non-NRC publication "Non-NRC publications" are publications authored by NRC employees prior to their employment by NRC.
NPARC number	23000941
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Record identifier	674bdb2c-5b59-4fb8-bd62-29673550629f
Record created	2016-11-18
Record modified	2020-03-17

Date modified:: 2024-09-20