| Chickpea(Cicer arietinum) belongs to the Family Leguminosae, whose name is indicative of its shape. It is an annual or perennial herb growing in arid and semi-arid area of the world, it is also the second largest consumption legume and widely cultivated. It has been grown in XinJiang for 2500 years. Research shows that chickpea has several physiological effects,such as anticancer,antilipemic,andanti-angiocarpy properties.Extraction of the compounds and the development of health food have broad prospects.The resource of isoflavones is contained in chickpea, which is up to 0.33% in its germinated seeds. Cicer arietinum isoflavones(CAI) are effective in preventing the proliferation of cancer cells, decreasing blood lipids to prevent cardiovascular disease, curing osteoporosis.However,the researchs about Chickpea are limited not only in domestic but also in foreign, especially in inclusion and application.Due to the phenolic hydroxyl, isoflavones has strong chemical reactivity, poor stability, accelerated decomposition under conditions of light and heat, also easy to lose antioxidant activity and other biological functions,so its application and storage also subject to certain restrictions. Using Cyclodextrins to form inclusion compounds will significantly improve the physical and chemical properties of Cicer arietinum isoflavones.In this paper, the specific extraction methods of total isoflavones from chickpea was studied. Choose the germinant chickpea powder, degreasing by petroleun ether, using 65% ethanol and extracting the chickpea powder for two times (2 hours per time)under 85℃,then refined by macroporous adsorption resins after extracted by ethyl acetate to obtain the refinement. Confirm the maximum absorption wavelength is 260nm by scanning UV absorption spectrum compared with Biochanin A.The inclusion complexes ofβ-cyclodextrin(β-CD) and hydroxypropyl-β-cyclodextrin (Hp-β-CD) with cicer arietinum isoflavones(CAI) were prepared by the grinding method and characterized by infrared absorption spectrum. UV spectrophotometry was used to measure the solubility of inclusion complex as well as the changes of absorbance of Cicer arietinum isoflavones under different concentration ofβ-cyclodextrin(β-CD) and hydroxypropyl-β-cyclodextrin (Hp-β-CD), The inclusion equilibrium constant(Kfθ)of inclusion complex was determined by Benesi-Hildebrand equation and the thermodynamic parameters of the inclusion reaction,such as△Gθ△Hθand△Sθwere obtained from the inclusion constants at different temperatures.The whole inclusion process was controlled mainly by enthalpy and driven by Van Der Waals Forces.The inhibitory kinetics of cicer arietinum isoflavones on the activity of monophenolase and diphenolase contained in tyrosinase is studied via enzymological kinetic method. The changes of absorbance in time under different concentration of the extract are measured when take L-Tyrosine and L-DOPA(L-3,4-dihydroxyphenylalanine) as substrates respectively with Na2HPO4-NaH2PO4 as buffer solution(pH=6.8) at 30℃. It was found that Cicer arietinum isoflavones can inhibit both the monophenolase and diphenolase activities of tyrosinase well. The Cicer arietinum isoflavones concentrations corresponding to 50%inhibitory rate(IC50)are 0.07 mg/mL for monophenolase and 0.03 mg/mL for diphenolase,respectively.Moreover,cicer arietinum isoflavones can also extent the lag time of catalytic oxidation of L-Tyrosine by monophenolase,for example,0.08 mg/mL of Cicer arietinum isoflavones can extend the lag time from 1.26 min to 2.62 min. The inhibition kinetics of Cicer arietinum isoflavones analyzed by Lineweaver-Burk plots demonstrate that the inhibition effect of Cicer arietinum isoflavones for the oxidation of L-DOPA expresses as what a competitive inhibitor does.The inhibition constant of competitive reversible inhibitor KI were determined to be 0.0193 mg/mL.
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