Both mycalenitrile-15 (96) and mycalenitrile-16 (97) showed excellent and good inhibition effects against PTP1B (protein-tyrosine phosphatase 1B, a recognized target for diabetes and obesity) with IC50 values of 8.6 μmol/L and 3.1 μmol/L, respectively, resulting from the unsaturated side chain [110]. Here, PTPN1 is linked to obesity due to melanocortin 4 receptor deficiency.