title: Halenaquinone and xestoquinone derivatives, inhibitors of Cdc25B phosphatase from a Xestospongia sp.
abstract: Separation of an extract of a Xestospongia sp., guided by bioassay against Cdc25B, led to the isolation of nine compounds, halenaquinone (1), xestoquinone (2), adociaquinones A (3) and B (4), 3-ketoadociaquinones A (5) and B (6), tetrahydrohalenaquinones A (7) and B (8), and 13-O-methyl xestoquinol sulfate (9). The structures of the new natural products 6 and 9 were established on the basis of extensive one- and two-dimensional NMR studies. Compounds 1, 4, and 6 inhibited recombinant human Cdc25B in vitro with IC50 values of 0.7, 0.07, and 0.2 microM, respectively, and were 19- to 150-fold less active against two related protein phosphatases. Compound 4 blocked cell cycle progression through mitosis.
authors.affiliation: Department of Chemistry, M/C 0212, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors.forename: Shugeng
authors.initials: S
authors.lastname: Cao
authors.forename: Caleb
authors.initials: C
authors.lastname: Foster
authors.forename: Marni
authors.initials: M
authors.lastname: Brisson
authors.forename: John S
authors.initials: JS
authors.lastname: Lazo
authors.forename: David G I
authors.initials: DG
authors.lastname: Kingston
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors*; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011161:Porifera / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013057:Spectrum Analysis; D020687:cdc25 Phosphatases / Q000037:antagonists & inhibitors*
chemical_list: D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D011809:Quinones; C430084:halenaquinone; C068501:xestoquinone; C517008:CDC25B protein, human; D020687:cdc25 Phosphatases