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Smoking and Tobacco

Nicotine degradation products



I have been searching the internet for the past week and can not find any information on the chemical pathways that Nicotine follows as it degrads to cotinine, myosmine, ect. I wondering if anyone knows what these pathways are, both in the body and environmental degradation (exposure to Oxygen, Water, ect).


The biotransformation of nicotine is extremely complex and involves metabolic oxidation (phase 1) and conjugation (phase 2) reactions.  The most important metabolic reaction of nicotine in humans quantitatively is the formation of cotinine.  More than 70% of nicotine metabolism in humans proceeds via the formation of cotinine.  These reactions are catalyzed by certain isoforms of cytochrome P450 enzymes. 

Other products of biological oxidation include nornicotine and norcotinine.  There are also glucuronic acid conjugates of nicotine and its metabolites (by-products).  For detailed information on biotransformation of nicotine you may wish to refer to Analytical Determination of Nicotine and Related Compounds and Their Metabolites,  edited by John Gorrod and Peyton Jacob III.  Elsevier is the publisher. 

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Response by:

Karen L Ahijevych, PhD, RN, FAAN Karen L Ahijevych, PhD, RN, FAAN
Professor Emeritus
College of Public Health
College of Nursing
The Ohio State University