ISOLATION OF AN ANTIHISTAMINIC PRINCIPLE RESEMBLING TOMATINE FROM CROWN GALL TUMORS.

Antihistaminic activity was demonstrated previously in extracts of crown gall tumors by assaying in vivo. A crystalline substance isolated from the crude extracts has now been found to possess a high degree of potency against histamine, acetylcholine, bradykinin, and serotonin when assayed in vitro. The chemical characteristics of the substance resemble closely those of tomatine. When tomatine was investigated, it was found to have biological properties similar to those of the crystalline substances isolated from crown gall tumors. It seems likely that the antihistaminic properties of crown-gall tumor extracts are due to tomatine or a substance which closely resembles it.