Cao Shugeng, Foster Caleb, Brisson Marni, Lazo John S, Kingston David G I
Department of Chemistry, M/C 0212, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Bioorg Med Chem. 2005 Feb 15;13(4):999-1003. doi: 10.1016/j.bmc.2004.11.039.
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.
