title: Three new asterosaponins from the starfish Culcita novaeguineae and their bioactivity.
abstract: Bioassay-guided fractionation of the active n-BuOH extract of the starfish Culcita novaeguineae resulted in the isolation of three new sulfated steroidal glycosides (asterosaponins) 1, 2 and 3, as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Compounds 1-3 possess the same pentasaccharide moiety, beta-D-fucopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->4)-[beta-D-quinovopyranosyl-(1-->2)]-beta-D-xylopyranosyl-(1-->3)-beta-D-quinovopyranosyl, linked to C-6 of 3beta-sulfated steroidal aglycones and differ from each other in the side chains. Their structures were elucidated by extensive spectral studies and chemical evidences. Saponins 1 and 3 showed significant cytotoxicity against two cancer cell lines (IC50 values for 1:3.57 microg/mL [K-562], 2.55 microg/mL [BEL-7402]; for 3:3.75 microg/mL [K-562], 1.89 microg/mL [BEL-7402]), as well as hemolytic activity to rabbit erythrocytes (ED50 values: 16 and 31 microg/mL, respectively), while 2 was inactive in these bioassays.
authors.affiliation: Research Center for Marine Drugs, College of Pharmacy, Second Military Medical University, Shanghai, PR China. tanghaifeng71@126.com
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Tang
authors.forename: Yang-Hua
authors.initials: YH
authors.lastname: Yi
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Sun
authors.forename: San-Qi
authors.initials: SQ
authors.lastname: Zhang
authors.forename: Yue-Ping
authors.initials: YP
authors.lastname: Zhao
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D020128:Inhibitory Concentration 50; D008517:Phytotherapy; D011817:Rabbits; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology; D013215:Starfish
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D012503:Saponins