Enantioselective synthesis of dictyoceratin-A (smenospondiol) and -C, hypoxia-selective growth inhibitors from marine sponge
摘要:
Total syntheses of (+)-dictyoceratin-C (1) and (+)-dictyoceratin-A (smenospondiol) (2), hypoxia-selective growth inhibitors isolated from marine sponge, were executed. The absolute stereochemistry of the each compound was determined through the enantioselective total syntheses of them. It revealed that the unnatural enantiomers of them also exhibited the hypoxia-selective growth inhibitory activity against human prostate cancer DU-145 cells. (C) 2015 Elsevier Ltd. All rights reserved.
We describe the total synthesis of (±)-smenospondiol (1). Stereoselective construction of the drimane skeleton was accomplished by titanium(III)-mediated tandem radical cyclization of epoxide 9. Non-polar solvent is essential for the success of the tandem cyclization.
New Sesquiterpene Hydroquinones from a Taiwanese Marine Sponge <i>Polyfibrospongia australis</i>
作者:Ya-Ching Shen、Pei-Wen Hsieh
DOI:10.1021/np9605302
日期:1997.2.1
Two newsesquiterpene hydroquinones, polyfibrospongols A (1) and B (2), were isolated from the Taiwanesemarinesponge Polyfibrospongia australis Lendenfeld (Spongiidae) in addition to the known metabolites, dictyoceratin A (3), ilimaquinone (4), and 5-epi-ilimaquinone (9). The structures of these compounds have been determined mainly on the basis of spectral and chemical methods. Biological testing
-B (4a) were isolated from the Okinawanmarinespongesp. along with known compounds, furospinulosin-1 (1) and ilimaquinone (2). The structures of dictyoceratin-A (3a) and -B (4a) were determined on the basis of spectral data and their absolute configurations were deduced to be antipodal to that of ilimaquinone (2) by comparing an ozonolysia product(5) with that (6) derived from ilimaquinone (2).