A new phenolic amide, tribulusimide D (4-hydroxy-N-[3-(4-hydroxy-3-methoxyphenyl)-1-oxo-2-propen-1-yl]-3-methoxybenzamide) (1), together with a known phenolic amide, terrestriamide ((E)-3-(4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxyphenyl)-2-oxoethyl]-prop-2-enamide) (2) and a flavonol glycoside, quercetin-3-O-${eta}$-D-glucopyranosyl-($1{ ightarrow}6$)-${eta}$-D-glucopyranoside (3) were isolated from the $H_2O$ extract of Tribuli Fructus. Compounds 1 and 3 showed significant hepatoprotective activities, with $EC_{50}$ values of $13.46{pm}0.2$ and $7.06{pm}0.7{mu}M$, respectively, against tacrine-induced cytotoxicity in HepG2 cells.