Chemical constituents of Ulmus pumila L. and their chemotaxonomic significance

A phytochemical study of the leaves of Ulmus pumila L. led to the isolation of 32 compounds, including fourteen flavonoids, which include flavonols (1–6), dihydroflavones (7–11), and dihydroflavonols (12–14), five terpenoids, which include megastigmane glycosides (15–17) and triterpenoids (18–19), four sugars (20–23), one phenylpropanoid (24), two phenolic glycosides (25–26), two aromatic glycosides (27–28), one phenolic (29), one lignan glycoside (30), one steroid glycoside (31), and one fatty acid (32). The structures of these isolated compounds were determined by analysis of their NMR spectroscopic (¹H and ¹³C) data and by comparison with previously reported data. Compounds 4 and 8–10 were first reported from U. pumila; compound 12 was obtained from the genus Ulmus for the first time, while compounds 2, 6, 7, 11, 13, 15–17, 19–28, 30, and 32 have never been isolated from the Ulmaceae family. Chemotaxonomic studies have shown that the genus Ulmus may be closely related to the genera Hemiptelea, Zelkova, and Holoptelea.