Synthesis And Properties Of Alkyl β-D-Maltotriosides And Cholesterol Glycosides

Sugar-based surfactants are a class of environmentally friendly non-ionic surfactants.The raw materials are derived from natural renewable resources and have good environmental compatibility.It has very broad application prospects in industries such as daily necessities,cosmetics,medicine,biology,oil exploration and environmental protection.APGs play a very important role in sugar-based surfactants and have always been a hot spot for chemists to study.Through previous studies,it is found that,in a certain range,long chain APG has better performance than short chain APG.However,with the growth of the alkyl chain,the water solubility of glycosides also continues to decline,which hinders the development of APGs.In addition,SG and ASG are a class of substances with both biofilm and surfactant properties,and have been extensively studied in the pharmaceutical and food industries.However,the varieties of SG and ASG on the market are relatively single,which limits people’s further research on SG and ASG.In order to solve the above problems,this thesis has mainly done the following three aspects:1.In this paper,a series of alkylβ-D-maltotriosides（n=6-22）were synthesized by Helferich glycosylation method.Their structures were characterized by means of¹H NMR,H-H COSY and HRMS,which proved that the target compound was inβ-configuration.And its surface activity,foaming and foam stabilization,emulsification,hygroscopicity,thermal stability and thermotropic liquid crystal properties have been studied.The study found that C8-C20 can significantly reduce the surface tension of water,of which C16 has the strongest capacity,28.01 mN·m^-1.In addition,their micellization and adsorption processes are spontaneous,and they are more likely to be adsorbed on the liquid surface below the critical micelle concentration.We also found that C10 has good foaming property and foam stability.In addition,in toluene/water,rapeseed oil/water and n-octane/water,C9 and C10 have excellent emulsifying properties.Within 72 h,C18 has the most excellent hygroscopicity regardless of whether it is in a high humidity or low humidity environment.By studying the TGA of C10 and C18,it is found that they both have good thermal stability.It can be observed（n=8,9,10）that the liquid crystal exhibits a focal conic texture.2.In this paper,Helferich glycosylation method was used to synthesize SG and ASG.It includes six substances:acylcholesterol glucoside,acylcholesterol maltoside,acylcholesterol maltotrioside,cholesterol glucoside,cholesterol maltoside and cholesterol maltotrioside.Their structures were characterized by ¹H NMR and H-H COSY,and all glycolipids were inβ-configuration.3.In this paper,the synthetic route of alkylβ-D-maltoside（n=8,10,12,14）were optimized,which shorten the reaction route,reduce the reaction cost,reduce the environmental pollution and it is more suitable for industrialized production.