ABSTRACT
Ten compounds were isolated from the leaves of Rhizophora stylosa, one kind of mangrove plants distributed in the tropical and subtropical areas of the world. Their structures were identified as taraxerone (1), taraxerol (2), beta-sitosterol (3), careaborin (4), cis-careaborin (5), beta-daucosterol (6), isovanillic acid (7), protocatechuic acid (8), astilbin (9) and rutin (10), among which compound 9 and 10 were reported in this plant for the first time. Of these compounds, Compound 2 has been confirmed to have the abilities to inhibit the growth of Hela and BGC-823 with IC50 of 73.4 micromol x L(-1) and 73.3 micromol x L(-1), respectively. Compound 5 could inhibit the growth of BGC-823 and MCF-7 with IC50 of 45.9 micromol x L(-1) and 116.0 micromol x L(-1), respectively. Compound 9 and 10 were firstly reported to stimulate the proliferation of mice splenic lymphocytes markedly in a dose-dependent manner.