Probing the Pharmacophore for Allosteric Ligands of Muscarinic M<sub>2</sub> Receptors: SAR and QSAR Studies in a Series of Bisquaternary Salts of Caracurine V and Related Ring Systems
作者:Darius P. Zlotos、Stefan Buller、Nikolaus Stiefl、Knut Baumann、Klaus Mohr
DOI:10.1021/jm0311341
日期:2004.7.1
Allosteric effects on muscarinic acetylcholine M(2) receptors were examined in a series of bisquaternary salts of the Strychnos alkaloid caracurineV (6) and related iso-caracurineV, tetrahydrocaracurineV, and bisnortoxiferineringsystems. The compounds inhibited dissociation of the orthosteric antagonist [(3)H]N-methylscopolamine (NMS) from porcine cardiac M(2) receptors with EC(0.5,diss) values
with (phenylthio)acetic acid activated by bis(2-oxo-3-oxazolidinyl)phosphinicacid to give amide 15. Treatment of 15 with sodium hydride in tetrahydrofuran at 25 o C resulted in rapid conversion into a single diastereomer, 16. This same conjugate addition has been conducted at the sulfoxide oxidation level and also with a chiral sulfoxide to provide optically active compounds (Scheme VI). Conversion