New amides from the roots of Anisodus tanguticus

Two new amides (1 and 2) and four known analogues (3-6) were isolated from the roots of Anisodus tanguticus (Maxim.) Pascher. Their structures were determined by extensive spectroscopic analyses. The absolute configuration of compound 1 was determined by comparison of the calculated optical rotation (OR) value with the experimental OR value. All known amides were isolated from the genus Anisodus for the first time, of which compounds 3, 5, and 6 were first reported from the family Solanaceae. Furthermore, the chemotaxonomic significance of these secondary metabolites is discussed.