An Optimized and Universal Protocol for the Synthesis of Morpholine-2,5-Diones from Natural Hydrophobic Amino Acids and Their Mixture.

Morpholine-2,5-diones (MDs) are increasingly attractive compounds that can be produced using amino acid (AA) as a starting material. These compounds can undergo polymerization to produce biodegradable materials, namely, polydepsipeptides, that hold the potential to be used in medicinal applications. In this study, a simplified yet high-yield MD synthesis procedure was developed and applied to produce a range of MDs derived from hydrophobic AAs including Leu, Ile, Val, Phe, Asp(OBzl), Lys(Z), and Ser(tBu). Moreover, using a blend of hydrophobic amino acids (Leu, Ile, Val, and Phe), mixtures of MDs could be synthesized simultaneously. Finally, the polymerization of these MD mixtures was probed and proven successful. The concept investigated herein constitutes a novel path toward the valorization of protein-rich waste by producing renewable and biodegradable materials.