New triterpenoids and other constituents from the fruits of Benincasa hispida (Thunb.) Cogn.

Benincasa hispida (Thunb.) Cogn. fruits are widely consumed in China and tropical countries. This study identifies three new triterpenoids, 3α,29-O-di-trans-cinnamoyl-D:C-friedooleana-7,9(11)-diene (1), oleanolic acid 28-O-β-d-xylopyranosyl-[β-d-xylopyranosyl-(1→4)]-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside (2), and oleanolic acid 28-O-β-d-glucopyranosyl-(1→3)-β-d-xylopyranosyl-[β-d-xylopyranosyl-(1→4)]-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside (3), together with 12 known compounds, multiflorenol (4), isomultiflorenyl acetate (5), stigmasterol (6), stigmasterol 3-O-β-d-glucopyranoside (7), α-spinasterol (8), α-spinasterol 3-O-β-d-glucopyranoside (9), β-sitosterol (10), daucosterol (11), arbutin (12), nicotinic acid (13), (+)-pinonesinol (14), and ethyl β-d-glucopyranoside (15). The structures of compounds 1-15 were determined by spectroscopic and chemical methods. All the compounds with the exception of 4, 5, and 9-11 were isolated from B. hispida for the first time. The anticomplement activities of compounds 1-15 were assessed by Mayer's modified method. Compounds 1-15 showed no significant cytotoxic activity against HeLa human cervical, HL-60 human hepatoma, and SMMC-7721 human hepatoma cell lines.