Rosin-based Chiral Polymers As Stationary Phase In HPLC For Selective Separation Of Alkaloids To Research The Structure-activity Relation Between Alkaloids And The Polymers

In the present study,macroporous resins are widely used to purify natural alkaloids.However,most of the resins based on styrene(S)and divinylbenzene(DVB)for the monomers which probablely remained the toxic substances in the extraction and separation processes for the alkaloids.To overcome the purification issue associated with alkaloids,separation of four couples of alkaloids by rosin-base chiral polymers as stationary in HPLC have been studied in this thesis.The researches were elucidated as follows:1.The rosin-base chiral polymer microspheres have been produced by microsuspension polymerization of the monomer of methacrylic acid,cross-linker of maleic rosin ethylene glycol acrylate,dispersant and porogen.After sieving the particles as stationary phase which were packed the stainless column by wet Slurry column packing method.This novel stationary phase was characterized by scattering particle size analysis,scanning electron microscope,specific surface area and pore structure analysis,determination of acid value,thermogravimetric analysis.From the chemical and physical characterization of the particles,it can be seen that they are uniform which distibuted in the5～10μm range,mean specific surface area of 96.73 m~2/g,pore volumes of0.2824 cm~3/g and pore size of 11.68nm.In addition,with the use of beads own better thermal stability at the range of 25℃to 250℃.2.Study of the concentration of acetic acid and the temperature of column effects are based on experiences which were the separation of the four couples of alkaloids in chromatographic behaviors on rosin-base chiral polymer chromatography column by HPLC,such as theophylline-caffeine,tetrahydropalmatine-berberinehydrochloride,10-hydroxycamptothecin-camptot-hecin and taxane-docetaxel.The optimum separation conditions:methanol solution as mobile phase,flow rate of 0.3m L/min,and chromatography of column temperature at 25℃,the best chromatographic resolution of theophylline-caffeine reached 5.295±0.006;Acetic acid and methanol solution as mobile phase of 0.03%,and flow rate of 0.3m L/min,and chromatography of column temperature at 25℃,the best chromatographic resolution of tetrahydropalmatine-berberine hydrochloride reached 3.720±0.012;Acetic acid and methanol solution as mobile phase of 0.0025%,flow rate of 0.3m L/min,and chromatography of column temperture at 35℃,the best chromatographic resolution of 10-hydroxycamptothecin-camptothecin reached 2.141±0.011;methanol solution as mobile phase,flow rate of 0.3m L/min,and chromatography of column temperature at 34℃,the best chromatographic resolution of taxane-docetaxel reached 1.518±0.003.The important conclusions were gained from this study that the separation obtained satisfactory results that produce individual peaks generally are sought.To demonstrate this results,we combined the thermodynamics parameters such as△H,△S and△△G of the alkaloids based on the Van’t Hoff equation and calculated molecular size of alkaloids by Gaussian software simulation.Thus,theory predicted that the separation mechanism on the column.Furthermore,the studies reported in this paper provide that molecular size have a greater influence on the separation effect of alkaloids.3.To demonstrate this application,purifying and also for analysing the CPT content in the fruits of Camptotheca acuminata developed for packing columns of rosin-base chiral polymer microspheres.Fortunately,it produced good column efficiency and separation results as shown that the purity of CPT is90.4%.This experiment revealed that rosin-base chiral polymer chromatography column should prove useful in alkaloids analysis especially for the capture of CPT.