Potent antagonists

Picrotoxin, a potent antagonist of 7-aminobutyric acid at neural synapses, has been synthesized from (R)-(-) carvone as SM-goal (Sections 3.1 and 6.5). 

Ligands of the histamine Hs-receptors, new potent antagonists of the 2-thioimi-dazole type 97F295. 

Curare is a generic term for various South American arrow poisons. Curare has been used for centuries by the Indians along the Amazon and Orinoco rivers for immobilizing and paralyzing wild animals used for food. Preparations of curare are derived from Strychnos species, which contain quaternary neuromuscular alkaloids like tubocurarine. Tubocurarine is a potent antagonist at the nicotinic acetylcholine receptor. 

Tricyclics Preferential inhibition of noradrenaline Imipramine Potent antagonists of M-receptors, i-adrenoceptors... 

Mogg, A. J., Whiteaker, P, McIntosh, J.M., Marks, M., Collins, A.C., Wonnacott, S. Methyllycaconitine is a potent antagonist of alpha-conotoxin-MII-sensitive presynaptic nicotinic acetylcholine receptors in rat striatum. J. Pharmacol. Exp. Then 302 197, 2002. 

Bergman described indole C-3 acylation with acid chlorides via 1-indolylzinc chloride in the absence of palladium [108]. Davidsen and co-workers synthesized 86, which is a potent antagonist of platelet activating factor-mediated effects, using this Bergman acylation sequence... 

Parallel with the developments in the benzamide area, progress was also made in several nonbenzamide series of compounds. MDL 72222 (26) [20], atropine ester of 3,5-dichlorobenzoic acid, was the first selective 5-HT3 receptor antagonist and a potent antagonist of cisplatin-induced emesis in the ferret [21]. ICS 205-930 (27) [22,23 ], the tropine ester of 3-indolecarboxylic acid, exhibited similar pharmacological and antiemetic profiles. 

Other local anaesthetics such as procaine (4) and procainamide (5) were also shown to be antagonists of the sympathetic neuronal 5-HT3 receptor at concentrations well below those causing anaesthesia and led to the testing of metoclopramide (6), a D2 receptor antagonist and stimulant of gastrointestinal motility. This compound too was found to be a potent antagonist (pA2 7.2) at 5-HT3 receptors [52]. 

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