Deep Eutectic Solvent Catalyzed Synthesis Of Fatty Acid Stigmasterol Ester

The structure of phytosterols is similar to the steroidal structure of cholesterol,which can reduce the total cholesterol in human blood through competition and inhibition,thus reducing the effect of cardiovascular disease.Plant sterols are widely used in the fields of pharmacy,health care products and cosmetics.The deep eutectic solvent has outstanding performance in organic catalysis and high yield.It forms a two-phase system with organic matter and is easy to separate subsequent products.It is a current research hotspot.In this paper,a deep eutectic solvent was first introduced into the transesterification reaction of fatty acid stigmasterol ester,and a more systematic and comprehensive synthesis method of fatty acid stigmasterol ester was explored by combining the two methods of esterification and transesterification.Therefore,in order to further study the laws of plant sterol esterification and transesterification,oleic acid and stigmasterol were selected as the model substrates to optimize the esterification reaction conditions;at the same time,vinyl laurate and stigmasterol were selected as the model substrates for the transesterification reaction.Research,with a view to exploring the efficient synthesis of fatty acid phytosterol esters.The specific research contents and results of this dissertation are as follows:?1?Through studying the catalytic efficiency of 11 deep eutectic solvents for the esterification and transesterification of plant sterols,a deep eutectic solvent ChCl·2SnCl₂ was screened for high efficiency in the chemical synthesis?esterification,transesterification?of plant sterols catalyst.?2?In the experiment of chloric acid and stigmasterol catalyzed by deep eutectic solvent ChCl·2SnCl₂,the conversion of stigmasterol oleate to deep eutectic solvent increases first and then decreases;appropriately increase the amount of oleic acid,The reaction proceeds in the direction of synthesis;when the reaction temperature is lower than 130°C,its deformation increases significantly,and it continues to heat,and gradually no longer increases;within 5 hours of the reaction,the reaction can reach the thermodynamic reaction equilibrium.Optimized by responding to the synthesis process of stigmasterol oleate:under the conditions of 9.4%of deep eutectic solvent,1:3 molar ratio of alkyd,reaction temperature of 132°C and reaction time of 5.4 h,the maximum It can reach 81.5%.?3?By examining the reaction gradient,the synthesis of transesterification of vinyl laurate and stigmasterol was studied.The amount of solvent added in the deep eutectic solvent was 7.5%,the molar ratio of alkyd was 1:2 when the temperature was140°C and the time was 5 h.Under the conditions,it gradually reached 78.3%.?4?Decomposition of optimized reaction conditions into different fatty acids?lauric acid,myristic acid,palmitic acid,stearic acid,oleic acid,linoleic acid,conjugated linoleic acid,?-linolenic acid?Process and transesterification with vinyl carbonate?vinyl laurate,vinyl myristate,vinyl palmitate,vinyl stearate?.It was found that under the same conditions,taking the decrease as an indicator,the longer the fatty acid carbon chain,the higher the degree of unsaturation,and the lower the catalytic effect of the esterification reaction and transesterification reaction.?5?The product phytosterol esters were analyzed and identified by silica gel column chromatography,TLC,FT-IR,and NMR.By comparing the physicochemical properties of sterol and sterol ester,after the sterol is formed into an ester,the oil solubility of the sterol ester is better than that of sterol,which is increased by about 20 to 30 times.The acid value and peroxide value of the synthetic phytosterol esters comply with China's addition standards.