| Elaeagnus Angustifolia L.(Elaeagnus), is widely distributed in Northwest China. Its fruitis rich in many effective components including protein, carbohydrates, tannin, flavonoid,minerals and trace elements which have antidiarrheal, diuresis and hypoglycemic effects, andcan lower blood pressure and reduce blood lipid. In this paper, the fruits of E. angustifoliacollected from the Tengger Desert in Wuwei, were used as test material for studying theextraction rate and antioxidant activity of these extractions from different extraction solvent;The dynamic changes for content of polyphenol, flavonoid and proanthocyanidins, and theantioxidant activities during the tested growing period were evaluated; The content ofpolyphenol, flavonoid and proanthocyanidins, and antioxidant activity in different parts ofripe fruits were also determined; The extraction processes for polyphenol, flavonoid andproanthocyanidins were optimized; Adsorption and desorption capability of polyphenol bymacroporous resin were determined; In addition, the isolation and identification, antioxidantactivity of chemical constituents were also studied. The major findings were as follows:(1) In same conditions, the yield of extracts from the fruits of Elaeagnus AngustifoliaL.(EFEA) by50%ethanol and50%acetone was the highest, which possessed the strongestantioxidant activities. The EFEA obtained from the solvent systems of ethanol-water andacetone-water showed significant correlations with their antioxidant activities. The moreextraction rate of the extracts had, the more high antioxidant activities of the extractsdisplayed.(2) The weight and volume of the whole fruit increase in early growth period. Inaddition, the mass fraction of peel and fresh quickly increase in early period, the mass fractionof stone decrease in early period, and steadily grow closer to maturity.The content ofpolyphenol, flavonoid and proanthocyanidins obviously changes in the tested growing stage,and young fruit has high one; With the fruit constantly growing, the content of polyphenolgradually decrease. On the other hand, the content of flavonoid and proanthocyanidinsinitially increase, then decrease, and finally slightly increase. As far antioxidant activities, thefruit showed this trend of decreasing at firstly and increasing later in the growth.(3) There are significant correlations between the content of polyphenol, flavonoidand proanthocyanidins in the growth stage with the antioxidant activities of extracts, especially between proanthocyanidins and antioxidant activities. The antioxidant activitiesimprove when the content of EFEA increase. Moreover, there are correlations among thesedetermination methods of DPPH scavenging, reducing power and oxidation stability of lard.The result show these three methods can be used for determination the antioxidant activitiesof EFEA.(4)In different part of ripe fruit,the distribution of polyphenol,flavonoid andproanthocyanidins is different. The contents of these chemical components in the fresh arehigher than one in fruit stone and peel. In addtion, antioxidant activities in the fresh is alsohigher than in fruit stone and peel.(5) Response surface experiments based on single factor experiment were designed toresearch the impact of ethanol concentration,ultrasonic time,solid-liquid ratio,ultrasonicpower on yield of polyphenol, flavonoid and proanthocyanidins. Regression equations ofpolyphenol,flavonoid and proanthocyanidins were established. These equations couldeffectively predict the effect of polyphenol, flavonoid and proanthocyanidins yield inexperiment range. The conditions for polyphenol extraction were shown as ultrasonic power309.35W, ultrasonic time9.71min, solid-liquid ratio1:11.40, ethanol concentration48.10%,and the yield of polyphenol were8.58%under these conditions. The conditions forproanthocyanidin extraction were shown as ultrasonic power278.86W, ultrasonic time10.28min, solid-liquid ratio1:11.77, ethanol concentration49.36%, and the yield ofproanthocyanidin was4.53%; The conditions for flavonoid extraction were shown asultrasonic power293.18W, ultrasonic time8.04min, solid-liquid ratio1:20.20, ethanolconcentration63.84%, and the yield of flavonoid was5.37%.(6)In the six tested macroporous resins, the NKA-9was the most desirable adsorptionand desorption material for polyphenol of Elaeagnus Angustifolia L.. When25.12mL of1mg/mL sample was flowed through NKA-9resin column at a speed of1.0mL/min, theadsorption reached dynamic equilibrium. The adsorbed polyphenol could be completelyeluted with18.84mL of60%ethanol at1mL/min. After the purification,the content ofpolyphenol was4.8times of untreated one, and antioxidant activities and inhibition on HepG2tumor cells were obviously improved.(7) The EFEA significantly inhibited the proliferation of Human hepatoma cellsHepG2in vitro test. During first48h of culture stage, the inhibitory effect was in adoes-dependent manner. The study of the tumor-bearing mice model suggested that theextracts had significantly inhibitory effect on hepatoma cells H22, and improve immunity inmice. By pathology slice of tumor tissue, it could be found that there were obvious necroticareas of tumor cells from EFEA group, and cells grow in a more loose state; there were some apoptotic bodies and a lot of abnormal morphologic cells; The nucleus were seriously brokendown. In the acute toxicity test, the highest does of27.4g/kg did not show toxicity to mice.(8) Ten compounds were isolated by macroporous resin, silica column chromatoprap-hy, Sephadex LH-20and semi-prepared HPLC, in which eight compounds were identified byMP, UV, IR, MS,1H-NMR,13C-NMR, DEPT,2D-NMR, including seven flavonoids and aamino acid. Among these, compounds4(Quercetin3,4'-O-β-D-diglucoside),7(Quercetin3-O-β-D-Galactopyranoside-4'-O-β-D-glucopy-ranoside) and8(isorhamnetin3-O-β-D-Galactopy-ranoside-4'-O-β-D-glucopyranoside) were isolated for the first time from Elacagnus. Thecompound3,compound4,compound6,compound7and compound8had antioxidant activities,which sequence was compounds3＞compound4＞compound7＞compound6＞compound8. |
PDF Full Text Request