THE VERATRINE ALKALOIDS

Abstract

A review of the literature on earlier investigations of the alkaloid content of American hellebore or T'eratrum viride Aiton has been given by Seiferle, Johns, and Richardson (1).In the earlier work the occurrence of only jervine, pseudojervine, and rubijervine had been described.In their study they were able to isolate, in addition to these alkaloids, germine and its ester, protoveratridine.Our own more recent studies of the alkaloids of this plant have now added to the list and have also necessitated reinterpretations of earlier data.In a previous paper (2) we have reported on one phase of this study concerned with the isolation of pseudojervine and the new alkaloid veratrosine, which were characterized as glucosides of jervine and veratramine respectively.1These substances were found in the alcoholic extract of the plant material which followed preliminary extraction of the latter with benzene.A study of alkaloids contained in the benzene extract is the subject of the present report.The yield of partly crystalline crude basic material obtained after preliminary purification varied with different commercial samples of American hellebore, and any data given as to yields can be regarded only as approximations.About 11 gm.were extracted from each kilo of mat'erial.A preliminary separation of the bases was effected essentially as employed by Saito (3) in his study of Veratrum grandiflorum Loes.fil.By conversion to the sulfates a large sparingly soluble sulfate fraction was first obtained which after reconversion to the free bases was then transformed in alcoholic solution to the hydrochlorides.The sparingly soluble salt which crystallized was the hydrochloride of jervine, the principal alkaloidal constituent.From the more soluble hydrochloride fraction a crystalline'base was isolated which agreed very closely in properties with those recorded by Saito for veratramine.However, the analytical results obtained with our alkaloid were in closer agreement with the formulation C&II,,OzN than with that of C&H8sOzN derived by him.As a check on the identity of our substance, it was hydrogenated to a dihydro derivative with properties essentially as given by Saito for dihydroveratramine.Our analytical data again were more consistent with a formulation, C27H4102N.Saito's so called "diacetyl" derivative was also prepared.His analytical results as well as our own, however, are more satisfactory for a triacetylveratramine, 555