THE ACTION OF CRYSTALLINE THEVETIN, A CARDIAC GLUCOSIDE OF THEVETIA NERIIFOLIA

¹ From the Lilly Research Laboratories, Indianapolis, Indiana

Thevetin, a glucoside of be-still nuts (Thevetia neriifolia), has a digitalis-like action on amphibian and mammalian hearts. Its minimal systolic dose in frogs lies between 0.004 and 0.005 mgm. per gram, and its cat unit is 0.85 mgm. per kilogram. Thevetin is thus one-eighth to one-seventh as toxic but also one-eighth to one-seventh as potent as ouabain (G-strophanthin), weight for weight. Like other digitalis bodies, it causes nausea and vomiting in sublethal doses, raises the blood pressure, and stimulates isolated smooth muscle organs. Its action is less persistent than that of digitalis.

The kernels of be-still nuts contain approximately 3.6 to 4 per cent of thevetin as shown by physiological assaying.