PTPN1 and obesity due to melanocortin 4 receptor deficiency: Interestingly, in PTP1B (a recognized target for diabetes and obesity) inhibitory activity assay [18], compounds 7, 8, and 9 exhibited inhibitory activity with IC50 values of 75.5 μM, 63.9 μM, and 51.8 μM, respectively, as compared to the positive control of oleanolic acid (IC50 = 2.56 μM).