1‑Benzyl-3-aryl-2-thiohydantoin Derivatives as New Anti-Trypanosoma brucei Agents: SAR and in Vivo Efficacy
journal contributionposted on 10.07.2017, 00:00 by Andriy Buchynskyy, J. Robert Gillespie, Zackary M. Herbst, Ranae M. Ranade, Frederick S. Buckner, Michael H. Gelb
A high throughput screening and subsequent hit validation identified compound 1 as an inhibitor of Trypanosoma brucei parasite growth. Extensive structure–activity relationship optimization based on antiparasitic activity led to the highly potent compounds, 1-(4-fluorobenzyl)-3-(4-dimethylamino-3-chlorophenyl)-2-thiohydantoin (68) and 1-(2-chloro-4-fluorobenzyl)-3-(4-dimethylamino-3-methoxyphenyl)-2-thiohydantoin (76), with a T. brucei EC50 of 3 and 2 nM, respectively. This represents >100-fold improvement in potency compared to compound 1. In vivo efficacy experiments of 68 and 76 in an acute mouse model of Human African Trypanosomiasis showed a 100% cure rate after 4 days of oral treatment at 50 mg/kg twice per day.