Dihydrophenanthrenes and phenanthrenes from .

Two previously undescribed dihydrophenanthrene derivatives ( and ) were isolated along with twelve known analogues from the whole plant of . The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. The NMR data of known phenanthrene derivatives ( and ) were revised by 2D NMR. The isolated compounds were evaluated for cytotoxicity against three kinds of tumor cell lines (sw1990, HCT-116, and HepG2). Especially compounds and showed stronger antitumor effects, and the structure-activity relationship of these compounds was discussed.