Design, Synthesis and Anticancer Activity of Site Specific Short Chain Cationic Peptide

In spite of current progress in treatment methods, cancer is a major source of morbidity and death rate all over the world. Traditional chemotherapeutic agents aim to divide cancerous cells, are often associated with deleterious side effects to healthy cells and tissues. Host defense peptides Cecropin A and B obtained from insects are capable to lyses various types of human cancer cells at peptide concentrations which are not fatal to normal eukaryotic cells.

In the present work we have designed short chain α-helical linear and cyclic peptide from cecropin A having same cationic charge, hydrophobicity and helicity. Synthesis of designed novel short chain linear (10) and cyclic compound (12) was accomplished by using solution phase method. All the coupling reactions were carried out by using dicyclohexylcarbodiimide (DCC) as the coupling reagent at room temperature in the presence of N-methylmorpholine (NMM) as the base. The Structure of newly synthesized peptidse were elucidated by 1H-NMR, 13C-NMR, FT-IR, FABMS and elemental analysis data.Cytotoxicity of synthesized compound was tested against Dalton's Lymphoma Ascites (DLA), Ehrlich's Ascites Carcinoma (EAC) and MCF-7 cell lines by using MTT assay and 5-FU as reference compound.

From biological assessment,it was found that short chain cyclicpeptide12 showed high level of cytotoxic activity against DLA and EAC cell lines.

By utilizing a structure-based rational approach to anticancer peptide design from cecropin A, we were able to develop short chain linear and cyclic peptides having same charge, hydrophobicity and with improved activity. Systematically removing amino acids, we were able to retaining peptide charge and hydrophobicity/hydrophilicity in linear and cyclic peptide which results to optimize the anticancer activity against DLA and EAC cell lines.