Related Experiment Video
Updated: Aug 17, 2026

A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s
Published on: September 25, 2017
In vitro O-demethylation from a heterocyclic nitrogen: a novel metabolic reaction?
1Department of Biochemistry, College of Medicine, University of Ibadan, Nigeria.
Abstract:
1. O-Demethylation of 1-methoxyindole-3-carboxylic acid, in vitro, by determination of liberated formaldehyde, has been demonstrated using fortified 15,000 g rat liver supernatant fraction. 2. Results have been compared to those similarly obtained with a standard O-demethylation substrate, 4-nitroanisole, to substantiate and quantify the extent of the reaction. 3. Km values for 4-nitroanisole and methoxyindole-3-carboxylic acid were 8.9 and 6.5 mM, while Vmax values were 4.9, and 5.2 nmol HCHO produced/mg protein per min. 4. The significance of the metabolic O-demethylation reaction for N-methoxyindoles as a novel metabolic pathway is discussed in terms of pharmacological activity and biological reactivity.
Related Concept Videos
Preparation of Amines: Reductive Amination of Aldehydes and Ketones
2° Amines to N-Nitrosamines: Reaction with NaNO2
Nitrosation of Enols
Drug Metabolism: Phase I Reactions
Phase I Reactions: Oxidation of Carbon-Heteroatom and Miscellaneous Systems
In carbon-nitrogen systems, aliphatic and aromatic amines can undergo oxidative reactions. Secondary and tertiary amines, like those found in tricyclic antidepressants, can undergo N-dealkylation, a process that involves the oxidation of the alkyl group. In addition, oxidative...
Phase II Reactions: Methylation Reactions
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
