The Gas Phase Protonation Sites of Six Naturally Occurring Nicotinoids
- Tokyo Institute of Technology (Japan)
- Univ. of Washington, Seattle, WA (United States)
- Univ. of Washington, Seattle, WA (United States); Tokyo Institute of Technology (Japan); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Tokyo Institute of Technology (Japan); Chuo University, Kasuga (Japan)
We have determined the gas phase protonation sites of six naturally occurring nicotinoids, namely nicotine (NIC), nornicotine (NOR), anabasine (ANB), anatabine (ANT), cotinine (COT) and myosmine (MYO) from experimental cryogenic ion trap infrared spectroscopy and first principles electronic structure calculations. The structural motif of these compounds consists of a common Pyridine and a differing non-Pyridine rings. The protonation site on either of these two rings correlates with the nicotinoid’s biological activity (addiction). At room temperature NIC is a mixture of Pyridine and Pyrrolidine (non-Pyridene) protomers, NOR, ANB, ANT and COT are pure Pyridine protomers and finally MYO is mostly a Pyroline (non-Pyridine) protomer. Their biological activity (addiction) correlates with the protonation preference in the nonPyridine protomer, with the exception of MYO, which, although is protonated in the Pyroline (non-Pyridine) protomer, it is not addictive because of a conjugated p system that induces a flat structure that is not optimally interacting with the environment in the in the binding pocket of the human brain.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB)
- Grant/Contract Number:
- AC05-76RL01830; AC02-05CH11231
- OSTI ID:
- 2477172
- Report Number(s):
- PNNL-SA--197953
- Journal Information:
- Journal of Physical Chemistry Letters, Journal Name: Journal of Physical Chemistry Letters Journal Issue: 27 Vol. 15; ISSN 1948-7185
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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