Novel cyclotides from Hedyotis biflora has potent bactericidal activity against Gram-negative bacteria and E. coli drug resistance

作者：Wang, Dongguo^*; Chen, Jiayu; Zhu, Jianfeng; Mou, Yonghua

来源：International Journal of Clinical and Experimental Medicine, 2016, 9(6): 9521-+.

• Cyclotide
• H. biflora
• bacteria
• drug resistance

Background: Hedyotis biflora is a well-known herb in traditional Chinese medicine (TCM) which is used to treat various diseases, including cancer and inflammation. Recently, nine cytotoxic cyclotides were found in H. biflora, suggesting cyclotides may be bioactive ingredients in this herb. Materials and methods: In this present study, another two novel cyclotides: hedyotide B10 (HB10) and HB11 from the root of H. biflora were isolated, besides the known HB1 to HB9. By Edman degradation sequencing and gene cloning, we confirmed their amino acid sequences and obtained precursors of hedyotides. Radial diffusion assays (RDAs) and minimum inhibitory concentration (MIC) assays were used to screen their antimicrobial ability against four bacterial strains and its effect to bacterial drug resistance of Escherichia coli which generates extended-spectrum-lactamases (ESBLs). Results: Both cyclotides were bactericidal to E. coli and Streptococcus salivarius at low micromolar concentration, and both had the reverse effect to bacterial drug resistance. Conclusions: These results suggest that HB10 and HB11 might have potent activity against Gram-negative bacteria and bacterial drug resistance.

• 出版日期2016
• 单位台州学院