摘要:
A novel pyridine derivative, 3,5-bis-(1-methyl-pyrrolidin-2-yl)-pyridine, and a pair of diastereomers of 1,1'-dimethyl-[2,3]bipyrrolidinyl were isolated from the root of Nicotiana tabacum plants and identified as novel alkaloids by GC-MS analysis. The structures of these new alkaloids were confirmed by total synthesis. The affinities of these novel alkaloids, and other structurally related compounds for alpha L beta 2*, alpha 7* neuronal nicotinic acetylcholine receptors (nAChRs), and for nAChRs mediating nicotine-evoked dopamine release from rat striatum were also assessed. The results indicate that these compounds do not interact with alpha 7* nAChRs, but inhibit [H-3]nicotine binding to the alpha 4 beta 2* nAChR subtype. The results also demonstrate that these compounds act as antagonists at nAChRs mediating nicotine-evoked dopamine release from rat striatum. (c) 2005 Elsevier Inc. All rights reserved.