Oxidation of Nicotine and Ascorbic Acid

 

Oxidation of Nicotine

Nicotine is a natural alkaloid primarily found in tobacco plants, and it undergoes oxidation both in the body and in environmental conditions. The oxidation of nicotine can happen through enzymatic processes in the body or via non-enzymatic reactions.

1. Enzymatic Oxidation:

   • In the body, nicotine is metabolized mainly in the liver by the enzyme cytochrome P450 2A6. This enzyme oxidizes nicotine into nicotine-N-oxide, cotinine, and other metabolites.
   • The main pathway involves the oxidation of the pyrrolidine ring to form cotinine, the primary metabolite, which is further broken down into trans-3’-hydroxycotinine.
   • Cotinine is more stable than nicotine and has a longer half-life, making it useful for monitoring nicotine exposure in medical and research settings.

2. Non-enzymatic Oxidation:

   • Nicotine can undergo oxidation in the presence of air, light, and other oxidizing agents. The pyridine ring can also be oxidized, forming nicotine-N-oxide.
   • Additionally, nicotine can degrade when exposed to certain conditions, producing compounds like myosmine and nicotyrine.

Significance:

The oxidation of nicotine plays a role in the reduction of nicotine levels in tobacco products over time when exposed to air. In the human body, nicotine’s oxidation to cotinine is key in reducing its psychoactive effects.