Study On Separation And Purification Of6-gingerol And Its Molecular Inclusion Complexes

6-gingerol is the main hot component of ginger, which consists about75%of allgingerols. It has a variety of biological activities and pharmacological effects. However,due to its difficult purification, low solubility in water and unstable chemical propertiesand so on, its bioavailability in vivo is declined and utilization is restricted. Therefore,researching deeply into efficient purification technology of6-gingerol and exploringproducts with enhanced solubility and stability of6-gingerol are key to expand its wideapplication, accordingly are very beneficial for realizing the industrialization andcommercialization of6-gingerol.In this paper,6-gingerol was purified by macroporous adsorption resin. The eddects ofrelated factors on the separation effect were investigated in the process of experiment. And6-gingerol was refined by HPLC.6-gongerol and cyclodextrin (β-CD and HP-β-CD)inclusion complexes were manufactured by molecular inclusion technology and theirproperties were studied. This paper has completed the following research work:(1) Macroporous resin HPD-950possessed the best purification property, and theoptimum purification conditions were as follows: ethanol (which is used to dissolve crudeextract) concentration of35%(v/v), initial sample solution concentration of2.1mg/mL,sample pH of6.5, flow rate of1mL/min, dosage of5.5times column volume. And sampleswere desorbed by65%ethanol with the amount of6times column volume, while elutionrate was0.5mL/min. Under the mentioned conditions, purity of6-gingerol reached34.43%.(2) The6-gingerol cyclodextrin (β-CD and HP-β-CD) inclusion complexes wereprepared by vacuum freeze-drying method. Meanwhile, the inclusion complexes wereidentified by UV-visible spectra (UV-vis), liquid chromatography-mass spectrometry(LC-MS). It was identified that the6-gingerol cyclodextrin (β-CD and HP-β-CD) inclusioncomplexes were formed.(3) Inclusion ratios of6-gingerol cyclodextrin inclusion complexes were analyzed bythe phase-solubility method and equimolar series method. The results revealed that6-gingerol by both of the two cyclodextrins (β-CD and HP-β-CD) included at the ratio of1:1(molar/molar). The results were consistent with each other.(4) The thermodynamic parameters of intermolecular reaction between6-gingerol andcyclodextrins (β-CD and HP-β-CD) in the complexation were determined by phase-solubility method. The results indicated that three thermodynamic parameters ΔG, ΔH andΔS in the complexation gave negative values. It was identified that inclusion reaction is spontaneous and exothermic reaction.(5) DPPH and FRAP were employed to determine and compare the antioxidantactivities of6-gingerol and its inclusion complexes. IC50of6-G-HP-β-CD,6-G-β-CD and6-G were137.49mg/L,147.27mg/L and153.44mg/L with DPPH, separately. And FRAPdetermined EC1values of them as95.84mg/L,98.76mg/L and100.99mg/L, separately.The above3compounds did not display much difference in value of IC50and EC1. Itillustrated that inclusion reaction of6-gingerol and β-CD, HP-β-CD did not effectantioxidant activity of6-gingerol.(6) Stability of6-gingerol in inclusion complexes under acid, alkali, ultravioletradiation and high temperature was investigated. Among the results, the loss ratio of6-gingerol was higher and stability was lower than6-G-HP-β-CD and6-G-β-CD underadverse environmental conditions, while the later two inclusions had similar results,illustrating stability of6-gingerol was elevated in cyclodextrin inclusion complexes.