The Synthesis Of Calixarene And Its Natural Ester-type Catechins Extraction Performance

In this paper, tae polyphenol(the rough extract from tea)was usedas study object, calixarene and its derivatives were designed andsynthesized as extractant, the relationship of extraction behaviorbetween extractant and ester catechins momomer was investigated. Themain contents contain the three following respects:1. Three tert-butylcalix[n]arene(n=4, 6, 8) in different cavity sizewere synthesized. Tert-butylcalix[8]arene was modified by introducingmany kinds of functional groups at the "lower" rim. Octeacetate oftert-butylcalix[8]arene and seven different Octaalkylethers oftert-butylcalix[8]arene were prepared. The structures of the compoundssynthesized were determined by IR, ¹H NMR, MS spectra and elementalanalysis.2. All calixarene as extractants dissolved in the chloroform.Distribution behaviors of ester catechins monomers was studied in theaqueous and chloroform of two-phase system containing one ofcalixarene. The influence of different extractants, differentconcentrations of tert-butylcalix[8]arene and extraction temperatures onthe partition coefficients K and the separation factorsαfor estercatechins monomers were investigated. The experiment results show thatthe tert-butyl calix[8]arene is the best extractant that forms a more stablecomplexe with GCG (gallocatechin gallate) than withEGCG(epigallocatehchin gallate) or ECG (epicatechin gallate). Whenthe concentration of p-tert-butylcalix[8]arene is 3.79mmol/L, theextraction temperature is 4℃, the partition coefficients of K_GCG, K_ECG,K_EGCG are 0.987, 0.629, 0.449, the separation factors ofα₁ andα₂ are1.45, 1.596, respectively. The important factors influencing the extractionproperties of calixarene were discovered to be its cavity size andhydrogen bonding.3. A series of octaalkylethers of tert-butylcalix[8]arene as extractantsdissolved in the dichloromethane. Distribution behaviors of estercatechins monomers was studied in the aqueous and dichloromethane of two-phase system containing one of octaalkylethers oftert-butylcalix[8]arene. The influence of different extractants, differentconcentrations of octahexylether of tert-butylcalix[8]arene and extractiontemperatures on the partition coefficients K and the separation factorsαfor ester catechins monomers were investigated. The experiment resultsshow that the octahexylether of tert-butylcalix[8]arene is the bestextractant that forms a more stable complexe with ECG (epicatechingallate) than with EGCG (epigallocatehchin gallate) orGCG(gallocatechin gallate). When the concentration of octahexylether oftert-butylcalix[8]arene is 0.052mol/L, the extraction temperature is 5℃,the partition coefficients of K_GCG, K_ECG, K_EGCG are 0.53, 1.42, 0.30, theseparation factors ofα₁ andα₂ are 2.68, 1.78; respectively.