Discovery of novel thiourea derivatives as potent and selective beta3-adrenergic receptor agonists.

In the search for potent and selective human beta3-adrenergic receptor (AR) agonists as potential drugs for the treatment of obesity and noninsulin-dependent (type II) diabetes, we prepared a novel series of phenoxypropanolamine derivatives containing the thiourea moiety and evaluated their biological activities at human beta3-, beta2-, and beta1-ARs. Among these compounds, 4-nitrophenylthiourea (18i) and 3-methoxyphenylthiourea (18k) derivatives were found to exhibit potent agonistic activity at the beta3-AR, with EC(50) values of 0.10 and 0.16 microM, respectively, and no agonistic activity for either the beta1- or beta2-AR. In addition, they showed significant hypoglycemic activity in a rodent diabetic model.