It has been shown that the hypotensive properties of the roots and rhizomes of Veratrum viride, the American or Green Hellebore, are principally due to two hitherto undescribed crystalline alkaloids which have been named germidine and germitrine. Germidine has been identified as a mixed diester of the known alkamine germine, C27H43- OgN, with acetic add and l-α-methylbutyric acid. Germitrine is a triester of germine containing in addition to the above acids one mole of d-methylethylglycolic acid. Germitrine undergoes rapid methanolysis in 50% aqueous methanol at room temperature with the loss of the acetyl group and the formation of the diester alkaloid germerine (germine l-α- methylbutyrate d - methylethylglycolate), already known as a constituent of Veratrum album. The compound originally obtained from the triester fraction by crystallization from aqueous methanol and designated germitrine in our preliminary communication13 was actually slightly impure germerine. Germitrine is also degraded to germerine by chromatography on acetic acid-washed alumina. Germitrine is a powerful hypotensive agent. As little as half a microgram per kg. given intravenously elicits a marked fall in blood pressure in the anesthetized dog. The two diester alkaloids are somewhat less active. Protoveratrine (Veratrum album), the corresponding triester of the alkamine protoverine, is likewise unstable in aqueous methanolic solution; in this case the volatile methanolysis products yielded on hydrolysis acetic acid as well as inethylethylglycolic add. Germine pentaacetate on similar treatment is partially degraded to a monoacetate. © 1950, American Chemical Society. All rights reserved.