Structure–activity relationships of benzylidene anabaseines in nicotinic acetylcholine receptors of cockroach nerve cords
作者:Israt Sultana、Izumi Ikeda、Yoshihisa Ozoe
DOI:10.1016/s0968-0896(02)00139-6
日期:2002.9
Ten analogues of 6'-chloro-3-benzylideneanabaseine (CBA) bearing substituents Lit the ortho- and the para-positions of the phenyl group were synthesized, together with two related compounds, The affinity of the synthesized compounds for nicotinic acetylcholine receptors (nAChRs) in the nerve cord of the American cockroach (Periplancta americana L.) was examined by the radioligand binding assay using [H-3]epibatidine (EPI), a nAChR agonist. All 12 tested compounds inhibited [3H]EPI binding, showing K-i values ranging from 14.6 to 6830 nM. The potency variation of para-substituted CBA analogues was explained by the steric (DeltaB(1)) and electronic (sigma(p)) parameters of the para-substituents, or by the steric parameter and the charge of the NI nitrogen atom (qN(1)). Among the CBA analogues. only two compounds containing a dimethylamino group and a methoxy group at the paraposition showed high insecticidal activity against the German cockroach (Blattella germanica) when injected after pretreatment with metabolic inhibitors. High-affinity analogues of CBA might be suitable probes for use in classifying and characterizing insect nAChR subtypes. (C) 2002 Elsevier Science Ltd. All rights reserved.