Antibacterial and Antifungal Activity of Three Monosaccharide Monomyristate Derivatives

Microbial infections remains a serious challenge in food industries due to their resistance to some of the well-known antibacterial and antifungal agents. In this work, a novel monomyristoyl ester (fructosyl monomyristate) and two other derivatives (i.e., glucosyl and galactosyl monomyristates) were successfully synthesized from myristic acid and monosaccharides in two-step reactions. First, the myristic acid was converted to myristoyl chloride, and then the myristoyl chloride was reacted with fructose, glucose and galactose separately to produce the corresponding monosaccharide monomyristate derivatives. The structures of the synthesized products were confirmed by Fourier transform infrared (FTIR), proton and carbon nuclear magnetic resonance (1H- and 13C-NMR), and mass spectral (MS) data. The monomyristates esters were obtained in reaction yields of 45.80%−79.49%. The esters were then evaluated for their antimicrobial activity using the disc diffusion test. It was found that the esters exhibited a medium antibacterial activity against gram-positive bacteria; however, they showed a weak antibacterial activity against gram-negative bacteria. Amongst the esters, galactosyl myristate yielded the highest antibacterial activity against Salmonella typhimurium, Staphylococcus aureus and Bacillus subtilis, while glucosyl monomyristate exhibited the highest antibacterial activity only against Escherichia coli. Additionally, all products showed remarkable antifungal activity against Candida albicans. These findings demonstrate that monosaccharide monomyristate derivatives are promising for use as biocompatible antimicrobial agents in the future.