Facile and Scalable Synthesis of Tripeptides with a Pro‐Pro Scaffold at <i>C</i> ‐end: A TAG Approach

Abstract The Pro‐Pro ligated tripeptides Ile‐Pro‐Pro 4 (IPP) and Val‐Pro‐Pro 5 (VPP) isolated from the fermented milk exhibit marked anti‐hypertension activity. Additionally, the naturally occurring Pro‐Pro ligated tripeptide Gly‐Pro‐Pro 6 (GPP) exhibits antioxidant properties. These peptides have enormous potential to be used as dilatory supplements. In the present study, we achieved a scalable, convenient, and high‐yielding synthesis of IPP, VPP, and GPP along with two more hydrophobic Pro‐Pro ligated tripeptides (APP 7 , LPP 8 ) by employing the TAG technique. We used acid labile (2,4‐bis(octadecyloxy)phenyl)methanol as the TAG. We demonstrated synthesis of one of IPP at molar scale. We think that our method has the potential to be escalated to an industrial scale without much difficulty and they become available for general use as dietary supplements.