Antibacterial activity and cytotoxicity of l‑phenylalanine-oxidized starch-coordinated zinc (II)

Int J Biol Macromol. 2019 Feb 15:123:133-139. doi: 10.1016/j.ijbiomac.2018.11.057. Epub 2018 Nov 12.

Abstract

Zn (II) coordination compounds have aroused growing attentions as antibacterial entities. In the present work, we fabricated a new antibacterial complex of l‑phenylalanine‑oxidized starch-coordinated zinc (II) (l‑Phe-OSt→Zn (II)) by successive reactions of oxidization, Maillard and coordination. Maillard reaction occurred between l‑Phe and OSt to form l‑Phe-OSt, which was then coordinated with Zn (II) by carboxyl groups for l‑Phe-OSt→Zn (II). The complex showed good antibacterial activity and the antibacterial activity against E. coli was slightly poorer than B. subtilis. The presence of complex favored the generation of reactive oxygen species (ROS) in bacteria and the ROS level in B. subtilis was higher than that in E. coli. Furthermore, the toxicity of l‑Phe-OSt→Zn (II) towards HT-29 cells was very low. The characteristics of better antibacterial activity and less cytotoxicity endow l‑Phe-OSt→Zn (II) a great potential of application as a food additive.

Keywords: Starch; Zinc (II); l‑phenylalanine.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacillus subtilis / drug effects
  • Cell Line, Tumor
  • Cytotoxins / pharmacology*
  • Escherichia coli / drug effects
  • HT29 Cells
  • Humans
  • Microbial Sensitivity Tests / methods
  • Phenylalanine / pharmacology*
  • Reactive Oxygen Species / metabolism
  • Starch / pharmacology*
  • Zinc / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Cytotoxins
  • Reactive Oxygen Species
  • Phenylalanine
  • Starch
  • Zinc