Antioxidant and antibacterial activities of dodecyl tannin derivative linked with 1,2,3-triazole.

Dodecyl tannin derivative linked with 1,2,3-triazole was prepared by the click reaction of dodecyl azide and alkynylated tannin. The structure of tannin derivative was identified by FT-IR spectrometer and elemental analyzer, and the surface activity, antioxidant activity and antimicrobial activity of tannin derivative were studied. The surface tension of tannin derivative was significantly reduced because of the introduction of long chain alkyl groups, and the lowest surface tension was 38.87 mN/m at 1.0 mg/mL. The tannin derivative had strong ability to scavenge 1,1-diphenyl-2-picrylhydrazyl radical, the scavenging rate could reach 89.08% at 0.25 mg/mL. The tannin derivative exhibited strong antibacterial activity against E. coli and S. aureus due to the increased fat-solubility of tannin derivative and the introduction of antibacterial triazol groups in molecular structure of tannin derivative, and the bacteriostatic ratio of tannin derivative against E. coli and S. aureus were 92.16% and 89.21% at 2.0 mg/mL, respectively. The tannin derivative can be used as good candidates for antibacterial packaging or antioxidant supplements.