Preparation and properties of a new type of carbohydrate‐based cationic surfactant

Abstract

AbstractA new type of cationic surfactant, 6‐O‐monoesters of 3‐(trimethylammonio)propyl d‐glucopyranoside, was prepared in high yield by a simple chemoenzymatic synthesis. Surface‐active properties of the compounds were found to be highly dependent on the fatty acyl chain length in the 6‐O‐position with the dodecanoyl and tetradecanoyl esters exhibiting the highest ability to lower surface tension as well as having the lowest critical micelle concentration values. Furthermore, the dodecanoyl ester had excellent foaming properties. The new surfactants also showed antimicrobial activity. Thus, the most potent compound, the dodecanoyl ester, was able to inhibit growth of both bacterial (Gram‐positive as well as Gram‐negative) and fungal test strains. The antimicrobial effect was somewhat weaker compared to benzalkonium chloride, one of the most frequently used cationics for topical disinfection. However, compared to benzalkonium chloride, the new cationics exhibit a highly improved compatibility with anionic surfactants, as no precipitation took place even in highly concentrated solutions thereby providing a much more robust antimicrobial system. Finally, the new surfactants are expected to be readily biodegradable because they are carbohydrate ester‐based.