Brucin, an antibacterial peptide derived from fruit protein of Fructus Bruceae, B rucea javanica (L.) Merr

A novel antibacterial peptide specific to S treptococcus pyogenes was produced from dried fruit protein of B rucea javanica (L.) Merr. A mixture of active peptides from the fruit protein was produced in vitro by pepsin hydrolysis. The hydrolysate was purified by reverse‐phase HPLC , and antimicrobial peptides active against Gram‐negative and Gram‐positive bacteria were analysed using SDS ‐ PAGE and nano LC ‐ MS / MS . Here, four possible peptides were obtained and chemically synthesized for comparative study of the growth inhibition of Strep. pyogenes . One chemically synthesized peptide with a molecular mass of 1168·31 Da, His‐Thr‐Leu‐Cys‐Met‐Asp‐Gly‐Gly‐Ala‐Thr‐Tyr , showed the most potent antibacterial activity against Strep. pyogenes . This 11‐amino acid peptide was named Brucin. Its bacterial inhibitory activity was 16‐fold and 12·5‐fold higher than penicillin G and chloramphenicol, respectively, with a MIC value of 20 μmol l −1 . The results suggest that Brucin, a potent antibiotic peptide, may be developed as an alternative drug for the treatment of the disease caused by Strep. pyogenes . Significance and Impact of the Study An antibacterial peptide, named Brucin with specificity for Streptococcus pyogenes , was produced in vitro from dried fruit protein of Brucea javanica (L.) Merr. by pepsin‐catalysed hydrolysis. Its inhibitory activity towards the Gram‐positive bacteria was higher than penicillin G and chloramphenicol. The result suggested that Brucin may be applied for the treatment of the disease caused by Strep. pyogenes * .