Synthesis, Characterization and Antibacterial Properties of Dihydroxy Quaternary Ammonium Salts with Long Chain Alkyl Bromides

Five N ‐methyl‐ N ‐R‐ N , N ‐bis(2‐hydroxyethyl) ammonium bromides ( R = ‐benzyl (chloride, BNQAS ), ‐dodecyl (C12 QAS ), ‐tetradecyl (C14 QAS ), ‐hexadecyl (C16 QAS ), ‐octadecyl (C18 QAS )) were prepared based on N ‐methyldiethanolamine ( MDEA ) and halohydrocarbon. Five QAS were characterized by FTIR , NMR , and MS . BNQAS , C12 QAS , C14 QAS , and C16 QAS were confirmed by X ‐ray single‐crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus , B. subtilis , especially C12 QAS with the best antibacterial ability (100% to E. coli , 95.65% to S. aureus , and 91.41% to B. subtilis ). In addition, C12 QAS also displayed the best antifungal activities than BNQAS and C18 QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple.