Abstract:To clarify the chemical constituents in Casuarina equisetifolia, fourteen compounds were isolated by organic solvent extraction, fractionation, and a variety of chromatographic separation techniques. Based on spectroscopic data, their structures were identified as 5-hydroxy-3-methoxyphenyl-6-O-syringoyl-β-d-glucopy-ranoside (1), alpinoside A (2), heterophylloside C (3), 6''-O-vanilloylisotachioside (4), 3,4,5-trimethoxyphenyl-6-O-syringoyl-β-d-glucopyranoside (5), vanillin (6), syringaldehyde (7), 3,4-dihydroxybenzaldehyde (8), oleanolic acid (9), betulinic acid (10), β-sitosterol glucoside (11), daucosterol-6'-linoleate (12), (±)-lyoniresinol 2-O-a-rham-noside (13), and (-)-9-acetyl-isolariciresinol 9'-O-a-l-rhamnopyranoside (14). Among them, compound 14 is a new lignan derivative.