Stephan Bonnar and Josh Barnett , mixed martial arts (MMA) fighters from the UFC and PRIDE Fighting Championships , have also tested positive for the banned substance.  After the World Extreme Cagefighting show on January 20, 2006 Muay Thai turned MMA fighter Kit Cope also tested positive for boldenone.  Following the Strikeforce card on June 22, 2007 former PRIDE and UFC fighter Phil Baroni tested positive for boldenone, as well as stanozolol .  At a K-1 WGP event in Las Vegas on August 17, 2007 two fighters, Rickard Nordstrand and Zabit Samedov , both tested positive for boldenone.  Alexandre Franca Nogueira tested positive for boldenone in July 2008. 
ONC1-0013B inhibits AR activity in vitro. A. ONC1-0013B structure. B. LnCAP cells cultured (10% CSS) for 3 days, then treated with tested compounds in presence of 1nM DHT for 1 day. PSA expression plotted as percentage of vehicle control (DMSO; n=2, mean±SEM). Ki values: ± (ONC1-13B), ± (MDV3100), (ARN-509). Mean±SEM from 5 replicate experiments (except ARN-509). C. LnCAP cells cultured (10% CSS) for 3 days, then treated with tested compounds in presence of 1nM DHT for 5 days. Viable cells plotted as percentage of vehicle control (DMSO; n=2, mean±SEM). IC50 values: 30nM (ONC1-13B), 148nM (MDV3100), 240nM (ARN-509). D. Competitive-binding assay vs AR ligand Fluormone™ (PolarScreen™ Androgen Receptor Competitor Assay). IC50 values: 19nM (DHT), (ONC1-13B), (MDV3100).