Two new cucurbitane-type triterpenoid saponins, 2,20β,22β-trihydroxy-16α,23(R)-epoxycucurbita-1,5,24-triene-3,11-dione 2-O-β-D-glucopyranoside (1), 2,20β,22α-trihydroxy-16α,23(S)-epoxycucurbita-1,5,11,24-tetraene-3-one 2-O-β-D-glucopyranoside (2) were isolated from the fruit of Citrullus colocynthis (L.) Schrad. Their structures were elucidated by mass spectrometry, IR, 1D, and 2D NMR spectroscopy, etc. Besides, both of the compounds showed significant hepatoprotective activities at 10 μM against paracetamol-induced HepG2 cell damage.
Keywords: Citrullus colocynthis; Cucurbitaceae; cucurbitacin; saponin; triterpenoid.