title: Bioactive steroids from the brown alga Sargassum carpophyllum.
abstract: By activity-guided fractionation, two new sterols, 3beta,28xi-dihydroxy-24-ethylcholesta-5,23Z-dien (1) and 2a-oxa-2-oxo-5alpha-hydroxy-3,4-dinor-24-ethylcholesta-24(28)-ene (2), together with five known steroids, fucosterol (3), 24-ethylcholesta-4,24(28)-dien-3,6-dione (4), 24xi-hydroperoxy-24-vinylcholesterol (5), 24-ketocholesterol (6), 24R,28R- and 24S, 28S-epoxy-24-ethylcholesterol (7), were isolated from the brown alga Sargassum carpophyllum as active compounds causing morphological abnormality of Pyricularia oryzae mycelia. Compounds 1, 3, 4, 5 and 7 also exhibited cytotoxic activity against various cancer cell lines. The IC50 values for 1 and 5 against HL-60 were 7.8 and 8.5 microg/ml, 3 and 4 against P-388 were 0.7 and 0.8 microg/ml, whereas 7 against MCF-7, HCT-8, 1A9, HOS and PC-3 were 4.0, 8.8, 10.0, 10.0 and 7.2 microg/ml, respectively.
authors.affiliation: Research Center for Marine Drugs, School of Pharmacy, Second Military Medical University, Shanghai, China. haifeng_tang@21cn.com
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Tang
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang-Hua
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Yao
authors.forename: Qiang-Zhi
authors.initials: QZ
authors.lastname: Xu
authors.forename: Shu-Yu
authors.initials: SY
authors.lastname: Zhang
authors.forename: Hou-Wen
authors.initials: HW
authors.lastname: Lin
mesh_terms: D001681:Biological Assay; D004354:Drug Screening Assays, Antitumor; D005658:Fungi / Q000187:drug effects; D006801:Humans; D007928:Lethal Dose 50; D000459:Phaeophyceae / Q000737:chemistry*; D013256:Steroids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D013256:Steroids