Screening and profiling stilbene-type natural products with angiotensin-converting enzyme inhibitory activity from Ampelopsis brevipedunculata var. hancei (Planch.) Rehder.

In this study, we screened 10 resveratrol derivatives isolated from Ampelopsis brevipedunculata var. hancei (Planch.) Rehder (ABH) for angiotensin I converting enzyme (ACE) inhibitory (ACEI) activity. Among these compounds, (+)-hopeaphenol and (+)-vitisin A showed the lowest IC50 values (∼ 1.5 μM) toward ACE. In addition, the compounds' abundances and distributions in ABH were profiled using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Interestingly, trimers and tetramers of resveratrol were mainly obtained from the bark of ABH when 90% ethanol was used for extraction. This result implies that the antihypertension effect of ABH extract may be mainly contributed by (+)-hopeaphenol (F1) and (+)-vitisin A (F2) in the ABH bark due to their remarkable ACE inhibitions. Moreover, the sizes and structures of these compounds were further correlated to their affinities toward ACE using molecular docking calculations. The results showed that resveratrol tetramers interact with ACE more favorably than other smaller oligomers.