title: Cytotoxic Phyllactone Analogs from the Marine Sponge Phyllospongia papyrecea.
abstract: BACKGROUND
  A growing evidence indicates that marine sponge Phyllospongia sp. is one of rich sources of 20, 24-bishomoscalarane sesterterpenes with potent biological activities. In order to search more bioactive 20, 24-bishomoscalarane sesterterpenes for new drug discovery, chemical investigation was carried out on an Indonesian marine sponge P. papyrecea.
  
  
  METHODS
  Bioassay-guided fractionation was carried out on its dichloromethane extract. And nine compounds were purified and isolated using HPLC. Their chemical structures were determined by a combination of spectroscopic and spectrometric data, including 1D-, 2D-NMR and HRESI-MS. Their cytotoxic activities were performed on three human tumor cell lines A549, MCF-7 and HeLa using the CCK-8 method.
  
  
  RESULTS
  One new 20, 24-bishomoscalarane sesterterpene, phyllactone H (9), was isolated and elucidated together with phyllactones A-B (1-2) and D-G (3-6), 12α, 24-dihydroxy-20, 24-dimethyl-15, 17- scalaradien-25, 24-olides (7-8). Compounds 1 and 2, 3 and 4, 5 and 6, 7 and 8 were C-24 anomers and inseparable mixtures, respectively. The 1H and 13C-NMR data for 7/8 were firstly reported in this paper.
  
  
  CONCLUSIONS
  Compounds 1-9 possessed in vitro moderate cytotoxicities against A549, MCF-7 and HeLa cells with IC50 values of less than 25 μM.
authors.affiliation: School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China.
authors.forename: Huawei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Chemistry & Biochemistry, University of California-Santa Cruz, CA 95064, United States.
authors.forename: Phillip
authors.initials: P
authors.lastname: Crews
authors.affiliation: Department of Chemistry & Biochemistry, University of California-Santa Cruz, CA 95064, United States.
authors.forename: Karen
authors.initials: K
authors.lastname: Tenney
authors.affiliation: Josephine Ford Cancer Institute, Henry Ford Health System, Detroit, Michigan 48202, United States.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Valeriote
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008968:Molecular Conformation; D011161:Porifera / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D007783:Lactones
keywords: Marine sponge; Phyllospongia papyrecea; cytotoxic activity; phyllactone; sesterterpene