Synthesis Of Hydroxyproline Lauryl Alcohol Ester And Study Of Antioxidation

Hydroxyproline lauryl alcohol ester comprises hydrophilic and hydrophobic groups both, the surfactivity of which is excellence. The disadvantage that hydroxyproline is indiscerptible in fat and can not get through the cell membrane is changed by esterification to enter the cells favoringly. At the same time, Hydroxyproline lauryl alcohol ester could be used for intermediate of medicament, because of the dissociative hydroxyl.In this article, L-hydroxyproline and lauryl alcohol were used as materials of esterification, paratoluene sulfonic acid was used as catalyzer, and toluene was used as the water schlepped. Dosage of catalyzer, time and temperature of reaction, scale of materials affecte the reactive rate of hydroxyproline. It is showed by the results of L9 (43) orthogonal tests that the optimum conditions are that the time of reaction was 10 hours; the temperature of esterification is 130℃;the molar scale of hydroxyproline and lauryl alcohol is 1:5; the molar scale of hydroxyproline and paratoluene sulfonic acid is 1:1.08. With the optimum conditions, the reactive rate of hydroxyproline is 85.57%. The effect of these factors is different that the molar scale of hydroxyproline and lauryl alcohol > temperature > time > molar scale of hydroxyproline and paratoluene sulfonic acid.Crystal and silica gel column chromatography were used for purification of hydroxyproline lauryl alcohol ester. The advangtage of crystal are simply operation and fast separation, because of which crystal is used for getting low purity. Because the purity and the yield by silica gel column chromatography were both higher than crystal, silica gel column chromatography was chose to purify hydroxyproline lauryl alcohol ester in this article. The purity and yield of hydroxyproline lauryl alcohol ester were 89.46% and 78.62% by crystal, and 90.17% and 87.34% by silica gel column chromatography respectively. After silica gel column chromatography twice, hydroxyproline lauryl alcohol ester was prepared to freeze-dried powder, and was characterized the structure by IR and NMR.There are three hydrophilic group: carboxyl, -OH and–NH2 on the hydroxyproline, which form hydrogen bond with water and dissolve in water. Because of that the carboxyl is replaced with long-chain alkyl, hydrophilic capability of hydroxyproline is reduced; and the steric effect of long-chain alkyl blocks the effect of -OH and–NH- with water, that the solubility reduces significantly in water, but increases in fat. The oil-water partition coefficient increase from -1 to 0.5.The -OH and -NH- of hydroxyproline lauryl alcohol ester can be used for hydrogen donor, and deoxidize O2-·; hydroxyproline lauryl alcohol ester can form chelate compound with metallic ion, and stops the Fenton reaction, then stops the appearance of·OH. When the concentration of hydroxyproline lauryl alcohol ester is 10 mg/mL, the rate of O2-·elimination is 69.3%, and·OH elimination was 67.62%.