phytosterols and ethyl-acetate

In this work, synthesis of phytosteryl ornithine ester hydrochloride was studied for the first time using an intermediate phytosteryl N,N'-bis[tert-butoloxycarbonyl(BOC)]-ornithine ester. This method also involved esterification of phytosterols with N,N'-bis(BOC)-ornithine and deprotection. The maximum yield was 90% and deprotection of BOC group was more than 99% using the HCl/ethyl acetate method. As a result, thermal stability and water solubility as well as emulsifying activity and stability of phytosterols were improved through coupling with ornithine, which is favorable for their application in water-based food systems. We also observed increased bioaccessibility of phytosteryl ornithine hydrochloride (4.5%) and 65% of phytosteryl ornithine hydrochloride was hydrolyzed in vitro. These results indicated that ornithine phytosteryl ester hydrochloride can reduce dissolution capacity of cholesterol in vitro, representing improved cholesterol-reducing activity, which will further expand the applications of phytosteryl ornithine ester hydrochloride.

Topics: Acetates; Anticholesteremic Agents; Biological Availability; Cholesterol; Digestion; Emulsifying Agents; Esterification; Humans; Hydrolysis; Magnetic Resonance Spectroscopy; Ornithine; Phytosterols; Solubility; Soybean Oil; Spectroscopy, Fourier Transform Infrared; Water

The aim of this work was to produce a series of phytosteryl amino acid ester hydrochlorides by a two-step method, which involved esterification of phytosterols with N- tert-butoxycarbonyl (BOC) amino acid and deprotection of the BOC group. The highest yield of over 95.0% was obtained when the catalysts were the mixtures of 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochlide, 4-dimethylaminopyridine, and triethylamine. It was found that batch charging of the reactants and catalysts was conducive to improving the yield. In addition, over 99.0% of the BOC group deprotection degree was achieved using the HCl/ethyl acetate deprotection method. All of the compounds were characterized by fourier transform infrared spectroscopy, mass spectroscopy, and nuclear magnetic resonance spectroscopy. The emulsifying properties of phytosterols and phytosteryl amino acid ester hydrochlorides were also investigated. The results showed higher emulsifying properties of phytosteryl amino acid ester hydrochlorides, which could favor its wide application in food systems.

Topics: Acetates; Amino Acids; Catalysis; Emulsifying Agents; Esters; Hydrochloric Acid; Magnetic Resonance Spectroscopy; Phytosterols; Spectroscopy, Fourier Transform Infrared