Guar gum cinnamate ouzo nanoparticles for bacterial contact killing in water environment

Herein we report the synthesis of newer guar gum cinnamate esters (GGC) following a Hofmeister cation guided homogeneous phase reaction. High degree of substitution (DS) guar gum cinnamate was obtained using, cinnamic acid halide reactant at a 1:3 M ratio. The biopolymer was fully characterized in FT-IR,13C NMR, XRD and thermal analysis. Nanoparticles were further developed in a facile ouzo solvent diffusion technique. SEM studies confirmed quasi spherical shape of the nanoparticles (GGCN) with an average size of 200 nm. Nanoparticles GGCN, expressed antibacterial activity against water borne gram negative and gram positive bacteria. The MIC was recorded at 300 μg mL−1against Escherichia coli and 500 μg mL−1against Staphylococcus aureus. Bacterial contact killing was confirmed from the bacterial morphology studies in SEM. Thus, nanoparticles from GGC may be employed for bacterial killing and water decontamination. [Display omitted] •Guar gum cinnamate (GGC) esterswere synthesized from guar gum using a generalized homogeneous phase reaction.•Guar gum cinnamate nanoparticles (GGCN) were further prepared using surfactant free ‘Biopolymer Ouzo’ technology.•GGCN produced stable dispersion in water PDI 0.43; SEM studies confirmed quasi-spherical nanoparticles, size 200 nm.•GGCN proved a promising antimicrobial agent due to bacterial contact killing.•GGCN were active against both the Gram negative (E.coli) and Gram positive (S.aureus) bacteria.