Bitter principles of the cucurbitaceae. VII.—the distribution of bitter principles in this plant family

The distribution of the twelve known cucurbitacins in 45 species, belonging to 18 genera, is reported. In certain species the cucurbitacins occur exclusively as glycosides. Variations of bitter principle content in different parts and with age and origin of a plant have been found. An association of cucurbitacin B with D, G and H, and of cucurbitacin E with I, J and K is indicated. The relation between bitter principle composition and taxonomic divisions is discussed.