Aim To investigate the antitumor agents produced by marine-derived Penicillium flavidorsum SHK1-27.Methods The producing strain SHK1-27was fermented in a rotary shaker and bioactive metabolites in the fermentation broth were isolated through a bioassay-guided sepa-ration procedure.Structures of the bioactive compounds were investigated by spectroscopic meth-ods and their in vitro antitumor activities were assayed by the SRBmethod using K562 cells.Re-sults Eight anthraquinone derivatives were isolated from the fermentation broth of P.flavidor-sum SHK1-27 and were identified as nidurufin(1),averufin(2),8-O-methylaverufin(3),6,8-O-dimethylaverufin(4),versicolorin B(5),versicolorin A(6),versiconol(7)and averantin(8),re-spectively.Compounds 1-8 inhibited the proliferation of K562 cells and could be classified as strong(1 and 8 with the IC5o values of 12.6 and 27.7μmol·L"'respectively),moderate(2,5,6 and 7 with the ICso values of 72.4,91.0,98.7 and 93.4μmol·L-'respectively)and weak(3and 4 both with the same ICso value of>100μmol·L-')activity groups,respectively.The results showed some structure-activity relationships.Conclusion This is the first report of compounds 1-8 as the secondary metabolites of P.flavidorsum species,1,5 and 6 were isolated from fungal metabolites of the genus Penicillium for the first time,and 7 was found to occur in nature for the first time.The antitumor activities of compounds 1-8 on K562 cells were also reported for the first time in the present study.
