Curare Subject

It has long been known that quaternary ammonium salts can exert a curare-like action, and in recent years much attention has been given to the synthesis and pharmacological testing of such products work on this subject up to 1936 has been reviewed by Ing, and more recently a theoretical discussion of the relationship between structure and action in drugs of this type has been provided by Holmes, Jenden and Taylor.Chase, Lehmann and Yonkmann have compared the action of quaternary salts of quinine with that of -erythroidine hydrochloride and of dihydro- -erythroidine hydrobromide. Quinine ethochloride shows marked curariform action of short duration. ... 

The beanlike seeds of the trees and shrubs of the genus Erythrina, a member of the legume family, contain substances that possess curare-like activity. The plants are widely distributed in the tropical and subtropical areas of the American continent, Asia, Africa, and Australia, but apparently they are not used by the natives in the preparation of arrow poisons. Of 105 known species, the seeds from more than 50 have been tested, and all were found to contain alkaloids with curariform properties. Erythroidine, from E. americana, was the first crystalline alkaloid of the group to be isolated. It consists of at least two isomeric alkaloids, a and P-erythroidine both are dextrorotatory. Most experimental and clinical study has centered on the b form because it is more readily obtainable in pure state. P-Erythroidine is a tertiary nitrogenous base. Several hydrogenated derivatives of p-erythroidine have been prepared of these, dihydro-P-erythroidine has been studied most carefully and subjected to clinical trial. Conversion of P-erythroidine into the quaternary metho salt (p-erythroidine methiodide) does not enhance, but rather almost entirely, abolishes its curariform activity this constitutes a notable exception to the rule that conversion of many alkaloids into quaternary metho salts results in the appearance of curare-like action. 

The bisbenzylisoquinolines have been the subject of many pharmacological studies, motivated originally by the knowledge that quaternary alkaloids of this type are the active constituents of tube curare. Certain nonquaternary bisbenzylisoquinolines, notably belonging to the curine group, are also smooth muscle re-laxants many bisbenzylisoquinolines are hypotensive, and a few possess anti-... 

The South American Indian arrow and dart poisons known as curares are all concentrated aqueous extracts of plant materials, usually prepared according to well-established ritual. All are powerful poisons which cause rapid paralysis of voluntary muscle. The fascination of this subject is well presented in a monograph by McIntyre (1) on the history, preparation,... 

This same Brazilian calabash curare also yielded (28) a quaternary alkaloid, C2iH27N20 , mp of iodide 235°-238°, [a]D +41° (96% ethanol). This was named lochneram, since it was proved (28) to be identical with A lj-metho lochnerine (XLIX). Moreover, lochneram gave only acetaldehyde when subjected to ozonolysis and is therefore regarded as the pure ethylidene isomer (XLIX). 

Subcutaneous (5.0 mg) (Prostigmlne+Curare+PAMCl) 1 subject Subcutaneous (5.0 ng) (Tubocurare+Prostlgmlne+Atroplne)... 

Yes, I know that if we strictly immobilize a subject s eyeballs by injecting the eye musculature with curare, the subject will soon lose articulate visual experience. So in principle, someone might protest, there is no spatial phenomenological difference between vision and smell. But (i) we have to use an invasive and toxic drug, thus disrupting the normal phenomenology of vision, and (ii) it is unclear that what "experience" remains is properly called vision at all. 

M.A. Subramanian and A.W. Sleight, Rare earth pyrochlores 225 R. MiyawaM and I. Nakai, Crystal structures curare earth minerals 249 D.R. Chopra, Appearance potential spectroscopy of lanthanides and their intermetallics 519 Author index 547 Subject index 579... 

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