COMPARISON OF THE PRESSOR ACTION OF SOME OPTICAL ISOMERS OF SYMPATHOMIMETIC AMINES

¹ From the Lilly Research Laboratories, Eli Lilly and Company, Indianapolis

1. The presser activity of d- and l-epinephrine bitartrates has been compared in pithed cats. The ratio of the d- to the l-isomer is approximately 1:18.5.

2. The pressor activity of optical isomers of desoxyephedrine HCl, benzedrine sulfate, isobenzedrine l-mandelate, propadrine l-mandelate, and -propadrine l-mandelate has been evaluated in pithed dogs. In every instance the l-isomer is more active than the d-isomer. The racemic mixtures of desoxyephedrine HCl and benzedrine sulfate are intermediate in action between their l- and d-isomers.

3. Of the diastereoisomeric salts, namely, the optically active mandelates of the optically active amines, the l-mandelate has a relatively higher pressor activity as compared with the d-mandelate. Thus, l-benzedrine l-mandelate is more powerful than l-benzedrine d-mandelate, and d-isobenzedrine l-mandelate, more powerful than d-isobenzedrine d-mandelate.