Synthesis, characterization, and antibacterial property of novel starch derivatives with 1,2,3-triazole

• Four novel 1,2,3-triazole-linked starch derivatives were obtained via ‘click chemistry’.
• The derivatives had enhanced antibacterial activity compared with starch.
• The inhibitory index of CBTST attained 97% above at 1.0 mg/mL.
• The order of their antibacterial activity was consistent with the electron-withdrawing property of the 1,2,3-triazole groups.

Four novel starch-linked-1,2,3-triazole derivatives were synthesized including 6-hydroxymethyltriazole-6-deoxy starch (HMTST), 6-bromomethyltriazole-6-deoxy starch (BMTST), 6-chloromethyltriazole-6-deoxy starch (CMTST), and 6-carboxyltriazole-6-deoxy starch (CBTST). Their antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated in vitro, respectively. The inhibitory property of the obtained amphiprotic starch derivatives exhibited a remarkable improvement over starch. And the antibacterial indices of most of the products were higher than 60% and 40% at 1.0 mg/mL when the culture time was 8 h and 16 h, respectively. Moreover, the inhibitory index of CBTST attained 97% above at 1.0 mg/mL. Generally, the inhibitory activity decreased in the order: CBTST > CMTST > BMTST > HMTST > starch. Furthermore, the order of their antibacterial activity was consistent with the electron-withdrawing property of different substituted groups of the 1,2,3-triazole groups. The substituted groups with stronger electron withdrawing ability relatively possessed greater antibacterial activity.