Mechanism of action of local anesthetics. 6. Binding of local anesthetics to complementary membrane structures

Abstract

The function of various mol. groups in anesthetic agents such as N-(N-dimethylalanyl)-2,6-dimethylaniline (I) [19216-39-8], N-(N-dimethylphenylalanyl)-2,6-dimethylaniline [19216-40-1], and N-(N-dimethylphenylalanyl)ephedrine (II) [10385-91-8] and their interaction with structural proteins of innervated membrane (frog heart) was given. Under various pH conditions (6.2-8.3), the anesthetics were more active as the free base than as the acidic form. A comparison of the 50% inhibitory dose (LD50) of the acidic and basic forms of II isomers indicated that isomers having a D configuration in the amino acid portion of the mol. were more active than those with an L configuration; the basic II isomers were more active anesthetics than the acidic isomers; and the basic enantiomeric isomers differed in their order of decreasing activity from that of the acidic enantiomeric isomers.