A hitherto unknown alkaloid, shown by hydrolysis to be a ditiglyl ester of 3:6:7-trihydroxytropane, has been isolated from the roots of three species of Datura. The formation of 6:7-dihydroxy-3-tiglyloxytropane (meteloidine) by partial hydrolysis establishes the constitution of the new base as 7-hydroxy-3:6-ditiglyloxytropane.