Carboxylesterase Ces3 and Ces1f inhibitor (IC50 values are ~100 nM). Also inhibits ABHD6. Promotes lipid storage in adipocytes. Reduces weight gain in diet-induced obese mice and enhances glucose tolerance in diabetic mice. Orally active. The ability of WWL113 to induce UCP1 expression in brown adipocytes does not appear to be mediated by Ces3/1f inhibition, for a structurally distinct Ces3 inhibitor (WWL229) failed to have the same effect on UCP1 expression, whereas the urea version of WWL113 (WWL113U), which does not inhibit Ces3, retained the ability to induce UCP1