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）,β-sitosterol（3）,careaborin（4）,cis-careaborin（5）,β-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 μmol·L-1 and 73.3 μmol·L-1,respectively.Compound 5 could inhibit the growth of BGC-823 and MCF-7 with IC50 of 45.9 μmol·L-1 and 116.0 μmol·L-1,respectively.Compound 9 and 10 were firstly reported to stimulate the proliferation of mice splenic lymphocytes markedly in a dose-dependent manner.
