Study On The Synthesis Of Feruloyl Esters Catalyzed By Cation Exchange Resin

Ferulic acid(FA)is a phenolic acid,which can be widely found in plants.It has strong anti-oxidation,anti-cancer,anti-bacterial,and anti-ultraviolet properties.However,the poor solubility of FA in oil system and water system limited its application in food,cosmetics and pharmaceutical industries.FA can be modified to broaden its range of application.However,the modification of FA has many problems such as complicated reaction and high catalyst cost.Therefore,this topic use economical and environmentally friendly cation exchange resin as catalyst to catalyze the modification of FA by glycerol,glyceride and fatty alcohol to prepare hydrophilic/lipophilic feruloyl esters,thereby expanding the application range of FA.The ultraviolet absorption characteristics and photo-stability of the products were also evaluated,which could contribute to the development of sunscreen skin care products.Firstly,the cation exchange resins were used to catalyze the esterification of FA with glycerol to prepare feruloyl glycerol(FG).The types of cation exchange resins were screened and and the effects of temperature,time,substrate ratio and resin load on the reaction were investigated.The optimal reaction conditions were obtained through response surface experiment.Results showed that A-35 was the best catalyst.The maximum FG yield was 98.5±0.58%with 1:15 substrate ratio(FA:glycerol,mol/mol),14%catalyst load,and the vacuum system at 90℃for 7 h.The activation energy(Ea)of the esterification was53.71 k J/mol,frequencu factor was 1.50×10~6.FG had a maximum absorption peak at 326nm.The photo-stability of FG was good,which still has more than 85%anti-ultraviolet effect after ultraviolet irradiation for 96 h.Secondly,the cation exchange resins were used to catalyze the reaction of FA and glycerides to prepare feruloylated acylglycerols(FAGs).The effects of different ferulyl receptors and different reaction conditions on the transesterification were compared.The optimal reaction conditions were obtained through response surface optimization,and kinetic analysis were also performed.Results showed A-35 was selected as the best catalyst and glycerol monostearate(GMS)was selected as the feruloyl acceptor,the higher temperature and the catalyst load were contribute to the selective formation of FAGs.The optimal conditions were as follows:catalyst load 20%(w/w),temperature 98°C,substrate ratio 1:7(FA:GMS,mol/mol),reaction time 17 h and vacuum system,FA conversion was95.70±1.32%and FAGs yield was 93.32±1.64%.The Ea of FA conversion was 58.95k J/mol,frequencu factor was 1.70×10~7.FAGs had strong ultraviolet absorption at 280～350nm.The photo-stability was good,FAGs still has more than 67%anti-ultraviolet effect after ultraviolet irradiation for 96 h.Finally,the cation exchange resins were used to catalyze the esterification of FA and fatty alcohol to prepare feruloyl fatty alcohol esters.The types of cation exchange resins and fatty alcohols were screened,the influence of temperature,time,substrate ratio and catalyst load on the reaction were also investigated.The optimal reaction conditions were obtained through response surface optimization,and kinetic analysis were also performed.Results showed the HND-580 was best catalyst and dodecanol was selected as the ferulyl acceptor.The maximum FA conversion was 98.42±0.39%with 12%catalyst load,1:8substrate ratio(FA:dodecanol,mol/mol)at 87℃for 5.5 h.The Ea of FA conversion was46.60 k J/mol,frequencu factor was 1.81×10~5.Dodecyl ferulate had strong ultraviolet absorption at 280～350 nm.The photo-stability of dodecyl ferulate was good,which still has more than 85%anti-ultraviolet effect after ultraviolet irradiation for 96 h.