Separation Of Curcumene,Zingiberene And β-Sesquiphellandrene From Ginger Oleoresin

In this study, silver nitrate silica gel column chromatography was used to obtain higher levels of curcumene, zingiberene and β-sesquiphellandrene from the raw material ginger oleoresin that extracted by supercritical carbon dioxide. In order to obtain higher purity, the effects of the relevant factors on the separation were mainly investigated, and finally determined the appropriate process parameters.Firstly, the vinyls were separated from ginger oleoresin by HPD-100macroporous resin column chromatography. In contrast with the static adsorption results of eight kinds of macroporous resin HPD-100, ADS-7, ADS-17and so on, HPD-100resin was finally identified as the separation medium of vinyl and phenolic substances. The influence of the static adsorption time and solution concentration on the adsorption were investigated, the result indicated that in40%ethanol solution, HPD-100could be reached adsorption equilibrium via20min, and the adsorption became firmer when the column was rinsed by50%ethanol. In the process of HPD-100column chromatography, samples obtained under different eluent were analyzed by tracing UV to establish the UV elution curve, meanwhile the phenolic and vinyl samples were analyzed with high performance liquid chromatography. The results showed that the gradient eluent should be used in the column chromatography, where70%ethanol solution was used to separate phenolic compounds which contents lead to more than95%and90%ethanol solution was to obtain the vinyl material, that alkenes and phenols achieved fully separation in this process.Secondly, coordination adsorption processes of vinyl compounds on silica gel,silver nitrate silica gel surface were investigated. The static adsorption isotherms of curcumene, zingiberene and β-sesquiphellandrene on silica gel and silver nitrate silica gel surface showed that the adsorption process on silica gel did not conform to the Langmuir monolayer adsorption theory, but on silver nitrate silica gel adsorption it was the typical Langmuir adsorption process.however, the adsorbance of the vinyl compounds on silica gel is less than it on silver nitrate silica gel.The stability constants of silver ion coordination compounds of curcumene, zingiberene and β-sesquiphellandrene were calculated by diphasic method, there were2.41×10-3,1.46x10-2and5.39×10-3respectively. Thus, it can be seen that the stability of the three kinds of coordination compounds was zingiberene>(3-sesquiphellandrene> curcumene, curcumene was eluted firstly, β-sesquiphellandrene following, ultimately was zingiberene if appropriate solvent was selected.Finally, curcumene, zingiberene and β-sesquiphellandrene were separated from the vinyl eluent by means of silver nitrate silica gel column chromatography. The vinyl eluent was separated by thin-layer chromatography using silver nitrate silica gel plates as chromatography media and different proportions of a mixed solution of hexane and ethyl acetate as the developing agent. Finally V hexane:Vethy1-acetate=98:2was determined as the mobile phase in the column chromatography process.The samples obtained at different sample loadings and flowing rates were analyzed by silver nitrate silica gel thin layer chromatography and GC/MS, by comparing the analysis results, the optimum chromatography conditions were concluded as follows:modified silver nitrate silica gel as the separation medium, the length of the column was40cm, the sample loading of vinyl was4mL, the column was eluted using V hexane:Vethy1-acetate=98:2at the flow rate of2.0mL/min. The vinyl samples that obtained at the optimized conditions were detected by both GC/MS and HPLC, the results showed that the relative area percentages of the three vinyls were improved significantly. By GC/MS, the area percentage of curcumene increased from12.89%to97.22%, zingiberene from30.44%to89.24%, β-sesquiphellandrene from18.41%to86.71%, the yields of the three compounds were calculated as:curcumene81.39%, zingiberene79.15%, β-sesquiphellandrene84.05%. However in HPLC analysis, β-sesquiphellandrene were found its existence of UV absorption at232nm, in HPLC spectrum its area percentage reached93.39%and zingiberene was97.69%.