共查询到19条相似文献,搜索用时 46 毫秒
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本文采用NaOH水溶液对海南绳江蓠进行超声浸提制备绳江蓠粗多糖(GCP),通过单因素实验和正交试验,考察得出GCP最佳提取工艺条件为NaOH溶液质量浓度1.5%,提取温度70℃,液料比1∶40,提取时间水浴4h,超声1h,提取率为20.01%,总糖含量为26.00%。对绳江蓠粗多糖进行乙醇沉降分级纯化,得到3种多糖组分GCP20、GCP40、GCP50,凝胶渗透色谱结果表明三种组分数均分子量分别为117kDa、116kDa和113kDa。电子自旋共振法测试GCP20、GCP40、GCP50对·OH的清除活性,三种组分均有很好的自由基清除能力,20mg·mL-1GCP20的羟基清除率达81.4%。紫外可见分光光度计在734nm波长下测试GCP20、GCP40、GCP50对ABTS+·的清除活性,浓度为20mg·mL-1时,三种组分对ABTS+·清除率均接近100%,表明这三种组分均有很好的抗氧化活性。 相似文献
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通过体外试验初步研究芜菁籽提取物的抗氧化活性。用95%乙醇为溶剂提取芜菁籽,采用有机溶剂萃取法将提取物分为石油醚相,乙酸乙酯相,正丁醇相和水相等4个不同极性部位、同时测定了各相提取物对羟自由基,超氧阴离子自由基,DPPH自由基的清除能力,并与合成抗氧化剂BHT进行对照。结果表明,芜菁籽提取物的不同极性部位均有抗氧化活性,其抗氧化效果随着浓度的增加而增强,乙酸乙酯相和正丁醇相的还原能力及清除O-2.,DPPH和.OH的能力均强于水相和石油醚相,乙酸乙酯相和正丁醇相的抗氧化作用强,是天然抗氧化剂的良好来源,应对其进一步分离纯化。 相似文献
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黑果枸杞叶经水提醇沉, 离子交换柱层析和凝胶柱层析分离纯化, 得到平均分子量为79400的均一多糖组分LRLP3. 对该多糖的理化性质、 结构、 抗氧化活性及免疫活性的研究结果表明, LRLP3为多分支结构, 主链为(1→3)βGalp, 大部分半乳糖6位存在分支; 支链由(1→6)βGalp, (1→4)βGalp, (1→3)βAraf, (1→3)αArap, (1→5)βAraf和(1→2,4)αRhap组成, 非还原末端由αAraf, βGalp和βGlcp组成. LRLP3具有较强的还原能力, 可显著清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基、 羟自由基和超氧阴离子自由基, 有效抑制Cu2+/H2O2诱导的蛋白氧化损伤和H2O2诱导的细胞氧化损伤. LRLP3在体外对未经诱导和经刀豆蛋白(ConA)或脂多糖(LPS)诱导的小鼠脾细胞增殖均有促进作用. 相似文献
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采取超高压提取,DEAE-Sepharose Fast Flow和Sephadex G-100柱层析分离纯化得到虫草多糖(CMP),通过高效凝胶色谱(HPGPC)、气相色谱(GC)和傅里叶红外光谱(FT-IR)对其理化特征进行了表征,并对CMP抗氧化及免疫调节活性进行了测定.结果显示CMP是纯度较高杂多糖,由鼠李糖、甘露糖、葡萄糖和半乳糖4个单糖组成,结果表明超高压是一种高效的菌多糖提取技术,提取得到的CMP可以探索作为天然的抗氧化和免疫调节剂应用于功能食品和药品. 相似文献
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本文优化了蒙药漏芦花多糖的提取工艺,并评价其抗氧化和抗菌活性。以超声功率、超声温度、超声时间和浸泡时间为影响因素,多糖提取率为评价指标,在单因素实验的基础上利用正交试验优化提取工艺,测定漏芦花多糖对DPPH自由基、羟基自由基清除效果,检测其抗氧化活性,涂布平板法测定多糖抗菌活性。超声波辅助法提取蒙药漏芦花多糖的最佳工艺条件为超声功率180W,超声温度70℃,超声时间30min,浸泡时间40min,在此条件下多糖得率为1.125%。抗氧化实验表明,漏芦花多糖浓度在0.5~2.5mg·mL~(-1)范围内,随着漏芦花多糖浓度增加,总还原能力不断增强;其体外清除DPPH自由基能力也随浓度增大而增强,清除率最高达72.98%;当多糖浓度为1.5mg·mL~(-1)时,漏芦花多糖体外清除羟基自由基能力最强,为7.24%。漏芦花多糖浓度为12.8mg·mL~(-1)时,对沙门氏菌的抑菌圈直径为9.72mm。超声法提取蒙药漏芦花多糖操作简便、准确、灵敏、重现性好,漏芦花多糖抗氧化能力良好,且对沙门氏菌有一定的抑菌效果。 相似文献
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《化学研究》2015,(6)
采用超声酶法辅助提取肉苁蓉粗多糖,并用季铵盐沉淀法对肉苁蓉粗多糖进行精制,获得肉苁蓉精制多糖(UCEP1);以UCEP1和硫酸锌为原料,制备了肉苁蓉多糖锌配合物(UCEP1-Zn),对其结构进行了表征,并研究其抗氧化活性.结果表明,肉苁蓉粗多糖收率及含量分别为22.31%和48.50%,UCEP1中多糖含量为70.13%;UCEP1-Zn中-OH和-COO~-和Zn~(2+)发生了配位,其中锌含量为7.57%,且多糖链构象及多糖分子表面形貌发生变化;UCEP1-Zn的抗氧化能力显著高于UCEP1,且对ABTS~+自由基清除活性最好.该研究可为肉苁蓉多糖、新型锌营养素补充剂以及锌功能配合物的研究和利用提供参考. 相似文献
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采用单因素、Box-Behnken design (BBD)试验响应面(RSM)法优化超高压提取(UPE)红龙果果皮多糖(RDFPs)工艺,以提高多糖得率.最佳工艺条件为:提取时间42.75 s,温度51.61℃,压力316.44 MPa;在修订最优条件下RDFPs的实验得率为34.31%,与预测得率(34.5%)一致.用超滤法和Sephadex G-100分子筛凝胶分离得到多糖组分RDFP-1,RDFP-2,RDFP-3,RDFP-4和RDFP-5,相对分子质量分别为7 950,16 460,49 980,145 350和193 710,并对它们的理化性质和体外抗氧化活性进行了比较研究.结果表明,RDFPs含有76.84%~84.22%的中性糖,9.64%~18.55%的糖醛酸,0.06%~0.88%的蛋白质.傅里叶红外光谱(FT-IR)和紫外(UV)光谱显示这些组分都具有多糖的特征吸收峰.RDFP-1和RDFP-4对1,1-二苯基-2-苦基肼自由基(·DPPH)、羟基自由基(·OH)和超氧阴离子自由基(·O2-)的清除活性显著高于其他多糖... 相似文献
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A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide(PAP) was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%. 相似文献
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Laetevirenols F ( 1 ) and G ( 2 ), two novel stilbene tetramers with an unprecedented skeleton, were isolated from Parthenocissus laetevirens. Their structures were elucidated by spectroscopic analysis, including 1D‐ and 2D‐NMR experiments, and their possible biogenetic pathway was discussed. In addition, both compounds were determined to be potent singlet‐oxygen quenchers by electron paramagnetic resonance (EPR) experiments, which highlights their potential pharmacological applications in singlet oxygen mediated diseases. 相似文献
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The bioactivity of polysaccharides extracted from Adenophora Potaninii have been investigated[1,2], but its chemical structure has not been reported. We now describe the structure and the antioxidation activity of a water soluble polysaccharide, APl, which was extracted from the roots of Adenophora Potaninii by boiling water. The crude polysaccharide was isolated and purified by DEAE-cellulose and Sephadex G-200 column, thus, AP1 white powders, was obtained. 相似文献
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在室温及弱碱性条件下进行姜黄素自氧化反应,应用柱色谱分离、紫外吸收光谱(UV)、红外光谱(IR)、核磁共振波谱(NMR)和质谱(MS)等分析技术,分离并鉴定了主要自氧化产物的化学结构.针对反应进程,采用高效液相色谱-二极管阵列检测器(HPLC-DAD)分析技术,从底物消除和产物生成2个方面进行了定性及定量研究.以抗坏血酸作阳性对照,采用1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、羟自由基(·OH)和超氧阴离子自由基(O_2~(-·))体系,定量比较了产物和姜黄素的体外抗氧化活性.结果表明,姜黄素在室温及弱碱性条件下的降解消除以自氧化反应为主,姜黄素消除过程和自氧化产物生成过程均符合一级动力学特征.自氧化产物具有双环乙酰丙酮的骨架结构,并显示有DPPH·,·OH和O_2~(-·)等自由基清除活性,但作用强度均显著低于姜黄素,因此在姜黄素应用过程中应严格控制pH条件,避免发生自氧化反应. 相似文献
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Antioxidative Effect of Schiff Bases with o-Hydroxybenzylidene Groupon Free Radical Induced Hemolysis of Human Red Blood Cell 总被引:1,自引:0,他引:1
LUO Xu yang ZHAO Jian zhang LIN Ying jie LIU Zai qun * College of Chemistry Jilin University Changchun P. R. China 《高等学校化学研究》2002,18(3):287-289
IntroductionThe recent development of free radical biologyand medicine has provided a great deal of clinicaland experimental evidence indicating that the freeradical induced peroxidation of membrane lipids isassociated with a variety of chronic healthproblems,such as cancer,atherosclerosis andageing[1,2 ] . Both natural and synthetic antioxidantshave been used to trap peroxyl radicals and/orinitiating radicals to protect the membrane lipidsagainst free radical chain reactions,and hence mayhave… 相似文献
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The polysaccharides associated with free (planktonic) and surface-attached (biofilm) cells from cultures of Pseudomonas fluorescens strain B52 were compared. Variations in the attached matrix due to surface material (glass or stainless steel) were also analyzed. Two digestion methods were used to optimize the recoveries of sugars, uronic acids and acidic substituents. The yield of analyzable material after digestion reached 90% for the material associated to the biofilms, though only 20–30% for that bound to planktonic cells. The polysaccharide(s) in the biofilm had glucuronic and guluronic acids as main components, besides rhamnose, glucose and glucosamine. The proportion of glucuronic to guluronic acid was higher in the polysaccharide(s) found in biofilms formed on stainless steel than in those on glass. 相似文献
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Flavonoids in plants used for the treatment of various cardiovascular, cancer diseases have been reported to possess potential protective effects against oxidative injury. Ginkgo biloba leaves, known for their antioxidant activity, were chosen for this study. In this paper, 12 flavonoids in G. biloba leaves were identified by HPLC-diode array detection (DAD)-electrospray ionization MS. HPLC-DAD coupled with chemiluminescence detection was used to determine free radical scavenging activity of flavonoids. It was found that the flavonol glycosides could markedly inhibit the luminescent signal, which indicated that they are mainly responsible for the antioxidant activities of G. biloba leaves. Total antioxidant activity of these flavonoids was used to evaluate the differences of G. biloba leaves collected in 13 habitats. The combination of chemical and activity analysis can provide a valid method to quantify the bioactive components in G. biloba leaves, and this may be a more rational approach to the quality assessment of G. biloba leaves. 相似文献