Synthesis and Investigation of 3,5-Bis-linear and Macrocyclic Tripeptidopyridine Candidates by Using L-Valine, N,N′-(3,5-pyridinediyldicarbonyl)bis-dimethyl Ester As Synthon

Abstract Interest in the synthesis of heterocyclic organic molecules with peptide moieties has gained attention due to their potential biological activities. The current work aimed at synthesizing new macrocyclic tripeptide imides and evaluating their possible antimicrobial activities. A series of 11 derivatives were prepared from dimethyl 3,5-pyridinevalinyl ester either by NaOH or NH2NH2 treatment, followed by cyclization and further reaction with NaOH or NH2NH2. The majority of synthesized derivatives showed promising antibacterial and antifungal activities in comparison to standard known antibiotics. Compounds 5a and 7b showed the most potential antibacterial against Staphylococcus aureus and antifungal activities against Candida albicans, respectively.