Isopropylpyrone and Phenylpyrones from the Leaves of Hypericum monogynum

A new isopropylpyrone, hypemonone F ( 1 ), and a new phenylpyrone, hypemonone G ( 2 ), along with five known phenylpyrones, peplidiforone B ( 3 ), hypemonone C ( 4 ), hypemonone B ( 5 ), 3‐(1,1‐dimethyl‐2‐propen‐1‐yl)‐4‐methoxy‐6‐phenyl‐2H‐pyran‐2‐one ( 6 ), hyperenone A ( 7 ) were isolated from the leaves of Hypericum monogynum . Their structures were identified on the basis of the spectral data (IR, UV, HRESIMS, and NMR). The absolute configurations of 1 − 4 were determined by electronic circular dichroism and single crystal X‐ray analyses. All isolated compounds ( 1 − 7 ) were evaluated for their cytotoxic activities on tumor cells (HeLa and HepG2). Compounds 1 − 7 showed cytotoxic activities against HeLa cells with IC 50 values of 28.27 ± 2.65 to 89.02 ± 2.30 μM, and compounds 2 , 3 , 6 , 7 showed cytotoxic activities against HepG2 cells with IC 50 values of 68.44 ± 1.45 to 80.7 ± 1.66 μM.