New Hydrogenated Phenanthrene Glycosides from the Edible Vegetable Elatostema tenuicaudatum W.T.Wang with DPP-IV Inhibitory and Hepatoprotective Activity

Based on molecular networking-guided isolation, 15 previously undescribed hydrogenated phenanthrene glycosides, including eight hexahydro-phenanthrenone glycosides, four tetrahydro-phenanthrenone glycosides, one dihydro-phenanthrenol glycoside, two dimers, and two known dihydrophenanthrene glycosides, were isolated from Elatostema tenuicaudatum W.T.Wang, a popular regional edible vegetable at the northwest region of Vietnam. Their chemical structures were determined using extensive spectroscopic data: NMR and ECD calculations. Notably, the crude extract, along with compounds 5, 6, 8, and 14, demonstrated dipeptidyl peptidase IV inhibitory activity with IC₅₀ values of 220.5 ± 39.6 μg/mL, 141.7 ± 15.6, 151.2 ± 11.8, 107.9 ± 19.6, and 71.9 ± 8.9 μM, respectively. Molecular docking indicates compound 14 possesses the highest binding affinity with DPP-IV. Besides, compounds 1, 9, 11, and 14 exhibited significant hepatoprotective effects in acetaminophen-induced hepatotoxicity in HepG2. These findings suggested that E. tenuicaudatum can serve as a beneficial vegetable for individuals at risk of diabetes and chronic liver disease.