Phenylethanoid glycosides from the roots of Phlomis umbrosa.

The phytochemical study of the roots of Phlomis umbrosa Turcz. afforded three new phenylethanoid glycosides, 3'''-acetyl-O-betonyoside D (1), 2''', 3'''-di-acetyl-O- betonyoside D (2), and 3''', 4'''-di-acetyl-O-betonyoside D (3), along with five known phenylethanoid glycosides. Their structures were elucidated on the basis of spectroscopic data. The antitumor activity of the isolated compounds was investigated.