Synthesis, Characterization, Catalytic & Biological Activities of β-Peptides

Abstract

β-Amino acids-based peptides have gained much attention in synthetic community forthe last few decades. These acids are more flexible, conformationally more free due to the presence of additional carbon atom in chain and the ability to form more stable secondary structure, which make them a more promising candidate for drug designing in pharmaceutical industry, asymmetric synthesis and organocatalysis. The work presented in this thesis, concerned the synthesis of β-amino acid based- dipeptides, catalytic potential in direct aldol reaction and their biological evaluation. Two different chiral pool approaches were adopted for β3-amino acids’ synthesis; (i) Arndt-Eistert homologation, (ii) Direct homologation. The substitution of synthesized β3-amino acid at C-2 by -NH 2 substituent, (direct α- amination reaction of β3-amino acids). The β-amino acids coupling in solution phase for the preparation of different types of dipeptides resulted, proline-β3-amino ester dipeptides, proline-2, 3-diamino ester dipeptides, β-dipeptides and then screening in asymmetric aldol reactions in environmentally friendly solvents; water, brine and organic solvent (dry THF). The bioassay (Anti-fungal, anti-bacterial, and cytotoxicity) of protected β-amino-esters and protected-β-dipeptides was also performed.