cas: 5746-86-1 (±)-Nornicotine s-nornicotine

cas: 5746-86-1 (±)-Nornicotine s-nornicotine

CBNumber: CB4385206

Chemical Name: 3-(2-Pyrrolidinyl)pyridine

Molecular Formula: C9H12N2

Formula Weight: 148.21

CAS No.: 5746-86-1

Nornicotine is an alkaloid found in various plants including Nicotiana, the tobacco plant. It is chemically similar to nicotine, but does not contain a methyl group.

It is a precursor to the carcinogen N-nitrosonornicotine that is produced during the curing and processing of tobacco. Nornicotine can react in human saliva to form N-nitrosonornicotine, a known type 1 carcinogen

Nornicotine is a secondary tobacco alkaloid that is produced by the N-demethylation of nicotine. Nornicotine production and accumulation in tobacco are undesirable because nornicotine serves as the precursor in the synthesis of the well characterized carcinogen N′-nitrosonornicotine during the curing and processing of tobacco. Although nornicotine is typically a minor alkaloid in tobacco plants, in many tobacco populations a high percentage of individuals can be found that convert a substantial proportion of the nicotine to nornicotine during leaf senescence and curing. We used a microarray-based strategy to identify genes that are differentially regulated between closely related tobacco lines that accumulate either nicotine (nonconverters) or nornicotine (converters) as the predominant alkaloid in the cured leaf. These experiments led to the identification of a small number of closely related cytochrome P450 genes, designated the CYP82E2 family, whose collective transcript levels were consistently higher in converter versus nonconverter tobacco lines. RNA interference-induced silencing of the CYP82E2 gene family suppressed the synthesis of nornicotine in strong converter plants to levels similar to that observed in nonconverter individuals. Although each of the six identified members of the P450 family share >90% nucleotide sequence identity, sense expression of three selected isoforms revealed that only one (CYP82E4v1) was involved in the conversion of nicotine to nornicotine. Yeast expression analysis revealed that CYP82E4v1 functions as a nicotine demethylase.