Extracts of the marine sponge Niphates digitalis collected in Dominica showed strong activity in a cell-based assay designed to detect antagonists of the androgen receptor (AR) that could act as lead compounds for the development of a new class of drugs to treat castration recurrent prostate cancer (CRPC).
Assay-guided fractionation showed that niphatenones A (3) and B (4), two new glycerol ether lipids, were the active components of the extracts. The structures of 3 and 4 were elucidated by analysis of NMR and MS data and confimed via total synthesis. Biological evaluation of synthetic analogues of the niphatenones has shown that the enantiomers 7 and 8 are more potent than the natural products in the screening assay and defined preliminary SAR for the new AR antagonist pharmacophore, including the finding that the Michael acceptor enone functionality is not required for activity. Niphatenone B (4) and its enantiomer 8 blocked androgen-induced proliferation of LNCaP prostate cancer cells but had no effect on the proliferation of PC3 prostate cancer cells that do not express functional AR, consistent with activity as AR antagonists. Use of the propargyl ether 44 and Click chemistry showed that niphatenone B binds covalently to the activation function-1 (AF1) region of the AR N-terminus domain (NTD).
Written by:
Meimetis LG, Williams DE, Mawji NR, Banuelos CA, Lal AA, Park JJ, Tien AH, Fernandez JG, de Voogd NJ, Sadar MD, Andersen RJ. Are you the author?
Departments of Chemistry and Earth, Ocean & Atmospheric Sciences, University of British Columbia , 2036 Main Mall, Vancouver, B.C., Canada V6T 1Z1.
Reference: J Med Chem. 2012 Jan 12;55(1):503-14. Epub 2011 Dec 28.
PubMed Abstract
PMID: 22148427
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