Structure Elucidation and NMR Spectral Assignments of Two New Compounds From the Medicinal Plant Ampelopsis sinica

Chemical investigation of the aerial parts of the medicinal plant Ampelopsis sinica led to the isolation of two new compounds, ampesinones A ( 1 ) and B ( 2 ). The structures were determined based on detailed analysis of the 1 H NMR, 13 C NMR, 2D NMR, and HRESIMS data. Compound 1 is a chalcone derivative containing a rare 3,5‐dimethoxycyclohexa‐2,5‐dien‐1‐one moiety. Compound 2 features a chromone moiety containing a (5 E )‐7‐carboxyhept‐5‐en‐1‐yl side chain. The known compounds were determined to be 5‐hydroxy‐5‐(hydroxymethyl)furan‐2(5H)‐one ( 3 ), resveratrol ( 4 ), 1,1′‐oxybis(2,5‐di‐tert‐butylbenzene) ( 5 ), and isoferulic acid ( 6 ). Compound 3 was a new natural product. These compounds were evaluated for the cytotoxicity against MCF‐7 and SW480 cells. Compound 1 exhibited weak activity toward SW480 with an IC 50 value of 29.7 μM.