Selective oxidation of primary alcohol group in 1-monostearoyl glycerol mediated by 2,2,6,6-tetramethyl-1-piperidine oxoammonium ion

Abstract

Primary alcohol group of 1-monostearoyl glycerol (I-MS) was oxidized using 2,2,6,6-tetramethyl-1-piped dine oxoammonium ion (TEMPO)/sodium hypochlorite/sodium bromide at 25degreesC and pH 10.8. Regio-selective oxidation of primary alcohol without oxidation 13 of secondary alcohol group was confirmed by chemical shift at 175 ppm and no chemical shifts between 198-205 ppm in C-13-NMR spectra, and a sharp peak at 1,600 cm(-1) an IR spectra. Water solubility and dispersibility of the oxidized 1-MS increased from 0.5 to 7.3 mg/mL and from 42 to 90%, respectively. Emulsion formed by oxidized 1-MS had higher emulsion stability. Results revealed that oxidized 1-MS is more suitable for preparation of emulsion containing high concentration of water than for that containing oil.