ABSTRACT
A novel antimicrobial cyclic peptide, Brucyclin, was rationally designed from the original antibacterial plant peptide,Brucin. The chemically synthesized Brucyclin consists of amino acid sequence; (NH2- Gln-His-Thr-Leu-Cys-MetCys-Gly-Gly-Ala-Thr-Trp-COOH), with a molecular mass of m/z 1290. In the antimicrobial assay with 31 strainsof pathogenic microorganisms, the peptide exhibited the most antimicrobial activity with a minimum inhibitoryconcentration (MIC) values ranging from 50 to 100 μg/ml against two strains of Gram-negative bacteria (Vibriocholera non O1, non O139 and Klebsiella oxytoca), one strain of Gram-positive bacterium (Bacillus subtilis), andone strain of yeast (Candida albicans), respectively. Structural analysis of Brucyclin indicated that it has a neutralcharge with a hydrophobicity ratio of 50% and pI value of 6.72, respectively. The results from this study suggested thatthe Brucyclin is a new antibiotic peptide that might be an alternative potent drug for treatment of various infectiousdiseases caused by pathogenic microorganisms.