Principal Investigator: Irving Wainer
Funding Mechanism: National Institutes of Health-Intramural
ID number: 252346
Award Date: 10/1/2012
Institution: National Institute on Aging (NIA)
The majority of the thousands of compounds present in tobacco smoke have not been structurally identified, nor have their pharmacological activities been determined. In previously published research, investigators described an improved technique – called missing peak chromatography – for determining the pharmacologically active components of tobacco smoke based on online liquid chromatography affinity screens; the investigators demonstrated that a column containing immobilized nicotinic acetylcholine receptors (nAChRs) can be used to screen tobacco smoke condensates, to identify known and unknown compounds that bind to individual nAChR subtypes, and to produce a chromatographic fingerprint that can be used to establish active component patterns (ACPs). The goals of this project are to use missing peak chromatography to optimize and validate the determination of ACPs, to establish the role of this technique in the regulation of tobacco products, and to determine the effect of additives on the products produced by tobacco leaf combustion. Study aims include: (1) to screen tobacco smoke condensates obtained from standard, light and flavored cigarette brands for compounds that bind to the nAChRs and to establish ACPs; (2) to determine the binding affinity and functional activity of individual compounds contained in the ACP at several nAChR subtypes, and to determine if the compounds are agonists, competitive or non-competitive antagonists, and positive or negative allosteric modifiers; (3) to repeat the study using extracts from the same cigarettes used to obtain the tobacco smoke condensates in order to compare the ACPs, to identify the source of active components in the tobacco smoke condensates, and to establish ACPs that can be used to control tobacco products; and (4) to determine whether menthol affects the pyrolysis of tobacco leaf constituents that interact with nAChRs and whether vaporized menthol affects the binding of tobacco smoke condensate constituents with nAChRs. The study methodology will use missing peak chromatography to analyze tobacco smoke extracts and condensates and to characterize the pharmacological activity of compounds at the nAChR; the analysis will be repeated using non-combusted cigarettes and again after adding menthol to the tobacco leaves before combustion.