Isolation and structure elucidation of a novel androgen antagonist, arabilin, produced by Streptomyces sp MK756-CF1

In the course of screening for a new type of androgen receptor (AR) antagonist, we isolated a novel compound, arabilin, with two structural isomers, spectinabilin and SNF4435C, produced by Streptomyces sp MK756-CF1 Structure elucidation on the basis of the spectroscopic properties showed that arabilin is a novel polypropionate-derived metabolite with a p-nitrophenyl group and a substituted gamma pyrone ring Arabilin competitively blocked the binding of androgen to the ligand-binding domain of AR in vitro In addition, arabilin inhibited androgen induced prostate specific antigen mRNA expression in prostate cancer LNCaP cells The Journal of Antibiotics (2010) 63, 601-605, doi 10 1038/ja 2010 98, published online 25 August 2010