Muscle-Relaxing Ethers of Glycerol

Abstract

THE discovery of the useful applications of curare in medicine and surgery has directed attention to other substances which are capable of producing muscular relaxation in man. In 1910, Gilbert and Descomps¹ administered the α-phenyl ether of glycerol to guinea pigs and observed : “Au bout d'un laps de temps variant, suivant la dose injectée, de trois minutes à dix minutes, on voit apparaître un certain degré de parésie des membres, parfois précédée de quelques rares et courtes eontractures passagères. Cette paralysie incomplète est toujours transitoire, et sa durée oscille en général entre quinze et trente minutes ; une seule fois, elle persista une heure.” Launoy² studied the action of the same compound and observed a “résolution musculaire” and the antagonism of the drug to strychnine. Muscle-relaxing properties were later and independently observed in several glycerol ethers³, and one of these, the α-o-tolyl ether ('Myanesin'), was found to be effective in man⁴. The present note indicates some of the relationships which have been observed between the molecular structure of glycerol ethers and their muscle-relaxing power. For the purpose of discussion it is useful to consider the molecular median paralysing dose (P.D.₅₀/mol. wt.) in mgm. per kgm., that is, the mole-fraction of the glycerol ether which is required to paralyse 50 per cent of white mice to which it has been administered subcutaneously.