From the stems and twigs of the mangrove plant, Aegiceras corniculatum, seven new compounds, namely, 2-methoxy-3-nonylresorcinol (1), 5-O-ethylembelin (2), 2-O-acetyl-5-O-methylembelin (3), 3,7-dihydroxy-2,5-diundecylnaphthoquinone (4), 2,7-dihydroxy-8-methoxy-3,6-diundecyldibenzofuran-1,4-dione (5), 2,8-dihydroxy-7-methoxy-3,9-diundecyldibenzofuran-1,4-dione (6), and 10-hydroxy-4-O-methyl-2,11-diundecylgomphilactone (7), were isolated together with three known compounds, 5-O-methylembelin (8), 3-undecylresorcinol, and 2-dehydroxy-5-O-methylembelin. The structures of 1-7 were determined by spectroscopic methods. Compound 2 and 5-O-methylembelin showed in vitro cytotoxicity against the HL-60, Bel(7402), U937, and Hela cell lines.