Synthesis and serotonergic activity of 2-oxadiazolyl-5-substituted-N,N-dimethyltryptamines: novel antagonists for the vascular 5-HT1B-like receptor
作者:Gerard P. Moloney、Graeme R. Martin、Neil Mathews、Steve MacLennan、Susan Dodsworth、Pang Yih Sang、Cameron Knight、Miles Maxwell、Robert C. Glen
DOI:10.1039/a903325d
日期:——
The synthesis and vascular 5-HT1B-like receptor activity of a novel series of 2-oxadiazolyl-5-substituted tryptamine derivatives 2 is described. Modifications to the 2-oxadiazolyl group R1, the heterocycle R2 and the length of the linking chain (n) have been explored. Several compounds were identified which exhibited moderate 5-HT1B-like receptor affinity. In particular, 2-(3-ethyl-1,2,4-oxadiazol-5-yl)-3-[2-(dimethylamino)ethyl]-5-[(4,4-dimethyl-2,5-dioxoimidazolidin-1-yl)methyl]-1H-indole (20) in which n = 1 had a pKB = 7.23 at the 5-HT1B-like receptor and >60 fold selectivity over α1-adrenoceptor affinity. This contrasts with the higher homologue derivatives such as 10 and 11 where n = 2 which exhibited decreased potency and selectivity for the 5-HT1B-like receptor. The 2-oxadiazolyl-5-substituted-N,N-dimethyltryptamine derivatives were found to be silent (as judged by the inability of angiotensin II to unmask 5-HT1B-like receptor mediated agonist activity in the rabbit femoral artery) and competitive 5-HT1B-like receptor antagonists with half lives of up to 1.5 hours in dog plasma and with good oral bioavailability.
本文描述了一系列新型2-噁二唑基-5-取代色胺衍生物2的合成及其血管5-HT1B样受体活性。对2-噁二唑基团的R1、杂环的R2以及连接链的长度(n)进行了探索性修改。发现了几种具有中等5-HT1B样受体亲和力的化合物。特别是,2-(3-乙基-1,2,4-噁二唑-5-基)-3-[2-(二甲基氨基)乙基]-5-[(4,4-二甲基-2,5-二氧咪唑啉-1-基)甲基]-1H-吲哚(20),其中n = 1,在5-HT1B样受体上的pKB = 7.23,相对于α1-肾上腺素受体亲和力有超过60倍的特异性。这与n = 2的高同系物衍生物(如10和11)形成对比,后者显示出对5-HT1B样受体的效能和选择性降低。发现2-噁二唑基-5-取代-N,N-二甲基色胺衍生物是无活性的(根据血管紧张素II无法在兔股动脉中揭示5-HT1B样受体介导的激动剂活性来判断),并且是竞争性的5-HT1B样受体拮抗剂,犬血浆中的半衰期可达1.5小时,并具有良好的口服生物利用度。