In the biological evaluation of these metabolites, acrepseudoterin (1) and [D-Leu]-ternatin (4) were identified as mild inhibitors of protein tyrosine phosphatase 1B (PTP1B), which is considered as the drug target for the treatment of type 2 diabetes mellitus and obesity. Here, PTPN1 is linked to obesity due to melanocortin 4 receptor deficiency.