Spasmolytic constituent of Ammi visnaga Lam., Umbelliferae. One of the active principles in the Egyptian traditional medicine known as “khella” that is used as a diuretic and vasodilator. See also: visnadine, khellin. Isoln and structure: Spth, Gruber, Ber. 74, 1492 (1941). Synthesis: Aneja et al., Tetrahedron 3, 230 (1958); Badawi, Fayez, Tetrahedron Lett. 1967, 1029. HPLC determn in A. visnaga fruit: M. M. El-Domiaty, J. Pharm. Sci. 81, 475 (1992).