title: Antichlamydial sterol from the Red Sea sponge Callyspongia aff. implexa.
abstract: Marine sponges are rich sources of natural products exhibiting diverse biological activities. Bioactivity-guided fractionation of the Red Sea sponge Callyspongia aff. implexa led to the isolation of two new compounds, 26,27-bisnorcholest-5,16-dien-23-yn-3β,7α-diol, gelliusterol E (1) and C27-polyacetylene, callimplexen A (2), in addition to the known compound β-sitosterol (3). The structures of the isolated compounds were determined by 1D- and 2D-NMR techniques as well as high-resolution tandem mass spectrometry and by comparison to the literature. The three compounds (1-3) were tested against Chlamydia trachomatis, an obligate intracellular gram-negative bacterium, which is the leading cause of ocular and genital infections worldwide. Only gelliusterol E (1) inhibited the formation and growth of chlamydial inclusions in a dose-dependent manner with an IC50 value of 2.3 µM.
authors.affiliation: Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg, Würzburg, Germany.
authors.forename: Usama Ramadan
authors.initials: UR
authors.lastname: Abdelmohsen
authors.affiliation: Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg, Würzburg, Germany.
authors.forename: Cheng
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Anastasija
authors.initials: A
authors.lastname: Reimer
authors.affiliation: Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Kozjak-Pavlovic
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt.
authors.forename: Amany K
authors.initials: AK
authors.lastname: Ibrahim
authors.affiliation: Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rudel
authors.affiliation: Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of Würzburg, Würzburg, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Hentschel
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK.
authors.forename: RuAngelie
authors.initials: R
authors.lastname: Edrada-Ebel
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt.
authors.forename: Safwat A
authors.initials: SA
authors.lastname: Ahmed
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001688:Biological Products / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D047128:Callyspongia / Q000737:chemistry*; D002692:Chlamydia trachomatis / Q000187:drug effects* / Q000254:growth & development; D015394:Molecular Structure; D053279:Polyynes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D011161:Porifera / Q000737:chemistry*; D012855:Sitosterols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001688:Biological Products; D012855:Sitosterols; D013261:Sterols; C000602683:callimplexen A; C000602682:gelliusterol E; D053279:Polyynes; C025473:gamma-sitosterol