虎杖多糖乙醇分级纯化及其抗氧化性

本文采用热水浸提及不同浓度乙醇(30%、50%、70%、90%)分级沉淀制得4组虎杖多糖(PCP-30、PCP-50、PCP-70、PCP-90),分别测定其得率、总糖含量及糖醛酸含量,采用红外和紫外光谱比较其光谱学性质差异,利用DPPH自由基清除实验及还原力实验考察其抗氧化性差异,并考察总糖含量、糖醛酸含量与抗氧化活性的相关性。结果显示,不同组分间多糖得率及含量有较大差异,PCP-70总糖含量(557.03 mg/g)及糖醛酸含量(284.85 mg/g)最高,且在DPPH自由基清除实验及还原力实验中表现出最高的抗氧化性,4组虎杖多糖红外检测都具有多糖的典型基团,紫外图谱波形近似,相关性研究表明总糖含量、糖醛酸含量与上述抗氧化模型均有一定的线性关系,表现出较强的相关性。因此,70%乙醇更适宜沉淀制备虎杖多糖,且所得虎杖多糖抗氧化性强。     

蛹虫草多糖的提取工艺优化及其抗氧化活性研究

以蛹虫草多糖(Cordyceps militaris polysaccharides,CMP)的提取得率为指标,通过单因素和响应面法对CMP的提取工艺进行优化。采用乙醇分级法,将CMP进行乙醇分级,分别得到4种多糖组分(CMP20、CMP40、CMP60和CMP80),并对不同多糖的得率、组分含量及抗氧化活性进行比较。结果表明,CMP的最优提取条件为温度84℃、液料比33∶1(m L/g)和时间128 min。在此条件下,实际提取得率为7.83%;CMP20、CMP40、CMP60和CMP80的得率分别为7.06%、15.07%、17.83%、25.23%。其中,CMP80的得率最高,蛋白含量最低,仅为1.47%;5种多糖均具有一定的抗氧化活性,CMP60的还原力和DPPH自由基清除率均为最高,CMP80的羟自由基的清除率最高。     

醇沉分级粗茶多糖的抗氧化活性比较及变化机制

以粗茶多糖提取物为原料,设置50%、60%、70%、80%、90%等5个浓度梯度乙醇沉淀分级制得茶多糖样品TPs-50、TPs-60、TPs-70、TPs-80和TPs-90,探明其沉淀分级特性、抗氧化活性表达及变化机制。结果表明,TPs-50和TPs-80得率可达到9%以上,茶多糖含量变化趋势为TPs-60TPs-50TPs-70TPs-90TPs-80。TPs-80中茶多糖含量为8.06%,占总析出量的14.76%,而可溶性蛋白含量占总析出量的43.82%。抗氧化活性实验表明,DPPH自由基清除率变化趋势为TPs-50TPs-60TPs-70TPs-80TPs-90,还原力亦呈降低趋势,与茶多糖含量变化趋势不一致。检测分析茶多糖样品中抗氧化组分含量发现,茶多糖、茶多酚、儿茶素类、总黄酮、咖啡因等组分皆有析出,析出量以TPs-50中最高。除茶多糖外,其他抗氧化组分析出量TPs-60、TPs-70和TPs-80之间逐渐变大,TPs-90中骤减至最低。相关性分析表明,茶多酚、总黄酮和咖啡因与茶多糖样品抗氧化活性表达呈显著性正相关,而茶多糖亦有正相关性,却未呈显著性相关,表明其抗氧化活性的表达更多依赖于其他活性组分的协同作用。     

牡丹叶多糖的提取纯化、分级制备及抗氧化性能研究

以牡丹叶为实验对象,建立牡丹叶多糖的提取及分离纯化方法,再采用不同体积分数(25%、45%、65%、85%)乙醇分级沉淀,得牡丹叶多糖PW-25、PW-45、PW-65、PW-85,采用红外光谱分析各组分的光谱学特征,并通过DPPH自由基和羟自由基清除实验对各组分体外抗氧化活性进行研究。结果表明:采用ZTC1+1-Ⅱ型天然澄清剂法脱蛋白和过氧化氢脱色法联用进行牡丹叶粗多糖的分离纯化,在此方法下牡丹叶粗多糖中蛋白脱除率为89.66%,色素脱除率为79.35%,多糖保留率为61.41%,得到PW-25多糖纯度达91.23%,得率为1.29%;4种牡丹叶多糖组分均具有一定体外抗氧化能力,其中PW-25对DPPH自由基和羟自由基具有明显清除能力,且半数抑制浓度(IC50)分别为15.36、65.77μg/m L,但均略差于VC(IC50分别为7.89、46.46μg/m L)。研究结果为牡丹叶多糖开发和应用提供基础。     

不同体积分数乙醇沉淀桑黄胞内多糖的理化性质及抗氧化活性

研究桑黄胞内多糖醇沉过程中乙醇体积分数对多糖得率、纯度、理化性质和抗氧化活性等的影响。结果表明：随着乙醇体积分数的增加,沉淀粗多糖的得率增加,而粗多糖中多糖含量呈现不规则的变化;不同体积分数乙醇沉淀获得的桑黄多糖中均含有木糖、甘露糖、半乳糖和葡萄糖。扫描电镜图像显示,低体积分数（65%、75%、85%）乙醇沉淀的多糖呈现均匀球状,高体积分数（95%)乙醇沉淀的多糖连成大块片状。桑黄胞内多糖体外抗氧化能力存在明显的量-效关系,95%乙醇沉淀的多糖对1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、羟自由基、2,2’-联氮-双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）自由基的清除效果最好,对Fe3＋的还原能力最强,抗氧化活性最高。     

化橘红多糖的提取纯化及抗氧化活性研究

对化橘红粗多糖及其纯化组分的抗氧化活性进行研究。化橘红粉末经热水提取、乙醇沉淀、sevage法脱蛋白、透析得到粗多糖,粗多糖经DEAE-52纤维素阴离子交换层析柱分离,得到2个纯化组份ECP1和ECP2。采用化学法分别测定了粗多糖及其纯化组分的体外清除自由基(DPPH.,.OH,ABTS.+)能力、还原能力。粗多糖的多糖含量为74.29%,经DEAE-52纯化的组分ECP1和ECP2的多糖含量分别为83.39%和85.77%。结果表明粗多糖及其两个纯化组分均具有较好的抗氧化清除自由基的能力,并且抗氧化能力与多糖浓度之间存在良好的相关性。其中ECP2的抗氧化清除自由基能力强于ECP和ECP1,但是低于对照VC。     

山茱萸多糖体外清除自由基和抗氧化作用研究

目的:研究山茱萸多糖提取物的体外抗氧化活性。方法:采用乙醇脱脂、热水提取、酶-Sevage法除蛋白、不同比例乙醇分级沉淀等方法获得山茱萸多糖提取物。分别采用Fenton反应体系、氮蓝四唑(NBT)光化还原法以及烘箱自氧化法研究山茱萸多糖的抗氧化性能,比较不同比例乙醇沉淀所得多糖的抗氧化活性。结果:不同乙醇浓度沉淀所得山茱萸多糖均具有一定的抗氧化活性,且呈显著的量效关系。其中,50%醇沉多糖对自由基的清除作用最为显著,当多糖质量浓度达到1.2mg/mL时,其对羟基自由基及超氧自由基的清除率分别为89.9%和87.1%。而90%醇沉多糖则具有较强的油脂抗氧化能力,其对猪油的抗氧化能力几乎与天然抗氧化剂BHT相当。结论:山茱萸中50%醇沉多糖及90%醇沉多糖分别具有较强的清除自由基能力和油脂抗氧化能力,是天然抗氧化剂的良好来源,可以进一步分离纯化。     

信阳毛尖茶末多糖的分离纯化和体外抗氧化活性研究

为实现废弃茶叶资源的再利用以及探究信阳毛尖茶叶末活性多糖的体外抗氧化活性,本研究首先利用不同的乙醇终浓度沉淀优化毛尖茶粗多糖提取,然后通过DEAE-52纤维素和Sephadex-100葡聚糖凝胶分级两次纯化,并进行纯度鉴定、分子量的测定、红外光谱分析以及体外抗氧化活性的测定等。研究结果表明,90%的乙醇终浓度得率最高,为2.47%;两次分级纯化后得到XPS-5B,纯度分别为92.4%;XPS-5B符合活性植物多糖结构特征,为β-型糖苷键多糖,分子量为41208 Da;XPS-5B体外抗氧化活性随着组分浓度的增加而逐渐增强,当XPS-5B浓度为1.20 mg/mL时对DPPH自由基和羟自由基的清除率分别为89.18%、90.62%,总还原力吸光值为0.536,与未纯化的毛尖粗多糖相比,具有较强的抗氧化活性。     

灵芝子实体和孢子粉纯化多糖体外抗氧化活性研究

为研究同源灵芝子实体和灵芝孢子粉纯化多糖的体外抗氧化活性,利用DEAE-650离子交换树脂,对提取获得灵芝子实体粗多糖(GLP)和灵芝孢子粉粗多糖(GLSP)进行分离纯化,GLP水洗脱得到GLP-1,0.2 mol/L NaCl洗脱得到GLP-2,GLSP水洗脱得到GLSP-1,0.2 mol/L NaCl洗脱得到GLSP-2。分别考察了4种纯化多糖的ABTS+自由基清除能力、DPPH自由基清除能力、羟基自由基清除能力和还原能力,结果表明,不同灵芝纯化多糖的抗氧化能力不同,GLP-2的4种抗氧化活性均最高,四种抗氧化能力最高,分别为98.09%、75.88%、81.55%和0.728。     

土党参多糖分离纯化及抗氧化能力分析

从土党参中分离纯化多糖并进行体外抗氧化能力分析。试验通过微波辅助提取、乙醇沉淀、Sevag去蛋白质、透析及DEAE-Cellulose 52柱层析、Sephadex G-100柱层析分离纯化土党参多糖,采用比色法测定其含量。以Vc为对照,检测多糖组分对DPPH·、·OH和O_2~-·自由基的清除能力,得出土党参多糖单组分的体外抗氧化能力。试验结果:微波提取土党参多糖得率为12.58%,在4次脱蛋白后,蛋白脱出率达到55.2%,多糖的损失率为26.4%。经柱层析分离纯化得到2个含量较高的多糖组分CLP-1和CLP-2。它们均对DPPH·、·OH和O_2~-·自由基有一定抑制作用并表现出量效关系。     

Effects of Ultrasonic Treatment on the Physicochemical Properties and DPPH Radical Scavenging Activity of Polysaccharides from Mushroom Inonotus obliquus

ABSTRACT: An ultrasonic technique was employed to extract polysaccharides from Inonotus obliquus (UPS). The effects of ultrasonic conditions on the recovery and 1, 1-diphenyl -2-picrylhydrazyl (DPPH) radical scavenging activity of UPS were evaluated. The physicochemical properties of UPS were analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and UV-visible spectrophotometry. Molecular weights of UPS were determined by gel permeation chromatography (GPC). The optimal ultrasonic conditions to obtain the highest recovery of polysaccharides were 80 min, 75 °C, and 100 w. While the optimal ultrasonic conditions to obtain the strongest DPPH scavenging activity of polysaccharide were 80 min, 95 °C, and 160 w. The differences were found by DSC, SEM, GPC analysis and no apparent differences were found from the UV-vis spectra of the polysaccharides after the ultrasonic treatment, which indicated that ultrasonic treatment might cause the physicochemical changes in UPS conformation and degradation of UPS chain but not the main groups. Ultrasonic technique was an effective method to extract bioactive polysaccharides from I. obliquus (UPS). Practical Application: Polysaccharides from Inonotus obliquus exhibited many biological activities including antitumor, antioxidant, hypoglycemic, immune-stimulating effects, and so on. Ultrasonic treatment is now an usual proceeding technique for the extraction of some bioactive constituents. But there was no information about the effects of ultrasonic treatment on the physicochemical properties and DPPH radical scavenging activity of polysaccharides from I. obliquus until now. Ultrasonic technique was an effective method to extract bioactive polysaccharides from I. obliquus (UPS) according to this study.     

Effect of extraction conditions on the antioxidant and antiglycation capacity of carbohydrates from Opuntia robusta cladodes

The extraction and characterisation of six crude polysaccharides from Opuntia robusta cladodes, as well as the assessment of their antioxidant and antiglycation activities in vitro, were examined. In this work, carbohydrates were extracted from defatted cladode's peels and pulps through a sequential extraction method in different aqueous medium (neutral, basic and chelating). The obtained polysaccharides were compared in terms of yield and physicochemical properties. Water‐soluble extracts showed the highest yield, while peel's chelating‐soluble extract gave high galacturonic acid content. Preliminary antioxidant in vitro tests suggested that peel's chelating‐soluble extract presented the highest scavenging activity towards DPPH free radicals and inhibition of linoleic acid peroxidation. Furthermore, all extracted polysaccharides showed good potential in inhibiting the nonenzymatic glycation reaction, particularly on the first 3 days of incubation. The obtained results suggested that Opuntia robusta extracts could be explored as natural antioxidant, especially those extracted with chelating agent.     

不同提取方法对松茸多糖理化性质及抗氧化活性的影响

目的研究不同提取方法对松茸多糖(polysaccharide of Tricholoma matsutake,TMP)的理化性质及抗氧化活性的影响,并以提取得率和抗氧化活性为依据,筛选出最优方法。方法采用热水浸提、超声提取、酶提取和微波提取等4种提取方法,获得4种相应的多糖。利用高效阴离子交换色谱和傅里叶红外光谱对4种多糖的化学特性进行了结构表征。结果 4种多糖的提取得率顺序为热水浸提多糖超声提取多糖酶提取多糖微波提取多糖。在4种多糖中,超声辅助多糖含量最高(48.98%),蛋白含量最低(0.2%)。抗氧化试验结果表明,超声辅助多糖的还原力和·OH的清除力均高于其他3种多糖;从清除DPPH活性来看,超声辅助多糖和热水浸提多糖的EC_(50)分别为1.06和0.98 mg/mL,二者活性相当,均远高于其他2种多糖。结论综合考虑提取得率、多糖含量和抗氧化活性,超声提取为最优方法。4种多糖的单糖组分基本相同,但它们的摩尔比有明显不同。     

Comparison of litchi polysaccharides extracted by four methods: composition,structure and in vitro antioxidant activity

Water-soluble polysaccharides (LCPs) were extracted from litchi, wherein LPS, LPH, LPP and LPM were extracted by ultrasound, hot water, ultra-high pressure and microwave methods, respectively. The physicochemical properties, components, structures and in vitro antioxidant activities of four LCPs were investigated. LPP was the highest in yield and purity, and most physicochemical properties of four LCPs were similar. FTIR showed that LPP, LPS and LPH had ɑ-dominating configuration in pyranose rings. SEM showed that four LCPs were different, and LPH and LPP had relatively smooth and compact surfaces. The Mw of LPS, LPH, LPP and LPM were 79 538, 320 213, 192 891 and 200 198 Da, respectively. All four LCPs consisted of fucose, galactose, glucose and rhamnose. Except for LPS, the other three LCPs contained mannose. Based on the results of in vitro antioxidant activity, 5 mg mL⁻¹ LPP presented the highest in DPPH and hydroxyl scavenging activity, while it ranked secondly in reducing power.     

Physicochemical properties and bioactivity of polysaccharides from Sargassum pallidum by fractional ethanol precipitation

Three polysaccharides (SPP-30, SPP-60 and SPP-90) were fractionated from Sargassum pallidum by 30%, 60% and 90% (v/v) ethanol, successively. Their physicochemical properties, antioxidant and antibacterial activities of SPP-30, SPP-60 and SPP-90 were comparatively investigated. The results showed that three polysaccharide fractions contained different neutral sugar, protein, uronic acid and sulphate contents. SPP-30 had the highest molecular weight (3.77–206.73 kDa), followed by SPP-60 (5.55–189.44 kDa) and SPP-90 (4.92 kDa). SPP-30, SPP-60 and SPP-90 were composed of fucose, arabinose, galactose, glucose, xylose and mannose but with different molar ratios. Scanning electron microscopy analysis suggested that they had different surface morphology and sizes of fragmentation. In vitro antioxidant assays suggested that SPP-30 and SPP-90 exhibited stronger scavenging activities against DPPH, ABTS and hydroxyl radicals than SPP-60. Moreover, SPP-30 and SPP-60 exhibited antibacterial activities against Staphylococcus aureus, while SPP-90 exhibited moderate antibacterial activity against both Staphylococcus aureus and Escherichia coli.     

提取方法对羊栖菜多糖理化性质及体外生物活性的影响

目的 全面评价提取方法对羊栖菜多糖理化性质、体外抗氧化能力以及降血糖活性的影响,以筛选出适用于羊栖菜多糖提取的最优方法。方法 以羊栖菜为材料,研究了热水提取法(hot water extraction, HWE)、碳酸钠提取法(alkaline-assisted extraction, ALAE)、氯化钙提取法(calcium chloride-assisted extraction, CAAE)以及微波辅助(microwave-assisted extraction, MAE)、超声辅助 (ultrasound-assisted extraction, UAE)提取方法对羊栖菜多糖得率、理化性质、体外抗氧化和降血糖活性的影响。结果 以水为溶剂提取羊栖菜多糖,得率相对较高,且MAE、UAE辅助提取可显著提高多糖得率。ALAE提取的羊栖菜多糖分子量最低(924.67 kDa)且热稳定性最好(Tmax=255.84 °C)。各种方法提取多糖的单糖组成类似,其中MAE提取的多糖其糖醛酸含量最高(半乳糖醛酸3.6%)。此外,水提多糖表现出相对较强的体外抗氧化和降血糖活性。结论 以水为溶剂更有利于羊栖菜多糖提取,此外超声、微波辅助可以强化其提取效果。本研究为羊栖菜多糖的高效制备与开发应用提供了科学依据。     

Quantitative and Qualitative Portrait of Green Tea Catechins (Gtc) Through Hplc

Green tea (Camellia sinensis) is a prosperous source of polyphenols, especially catechins. In the current research, an effort was made to optimize the extraction conditions for maximum yield of catechins from the local green tea Qi-Men. For the purpose, three different solvents were used, i.e., aqueous ethanol (50%), aqueous methanol (50%), and water at different time intervals (20, 40, and 60 min). Green tea catechins were quantified through HPLC using a C18 column and UV detector. The antioxidant activity of green tea catechins was measured through in vitro tests including DPPH radical scavenging ability and antioxidant activity. Results showed that extraction through aqueous ethanol resulted in maximum yield of green tea catechins (17400 ± 0.19 mg/100 g green tea leaves. Moreover, epigallocatechin, epigallocatechin gallate, epicatechin gallate, and epicatechin ranged from 4.26 ± 0.09 to 6.4 ± 0.2, 12.1 ± 0.123 to 17.7 ± 0.3, 1.32 ± 0.03 to 1.81 ± 0.02, 5.48 ± 0.099 to 8.6 ± 0.2 g/100 g of dry-extract, respectively. Furthermore, highest antiradical (80.65 ± 3.69%) and antioxidant activity (67.12 ± 3.08%) were observed in catechins extracted through aqueous ethanol.     

Extrusion treatment for improved physicochemical and antioxidant properties of high-molecular weight polysaccharides isolated from coarse tea

Extrusion processing was applied in pretreatment of coarse green tea and tea polysaccharide (TPS) was obtained, the physicochemical, thermal and antioxidant properties of which were comparatively studied by gas chromatography (GC), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), scanning electron microscopy (SEM). The antioxidant activity of TPS was evaluated by 1,1-diphenyl‐2-picrylhydrazyl (DPPH) radical scavenging assay. Results showed that extrusion treatment could improve the yield of TPS from 1.26% to 6.14%. The treatment resulted in the changes of TPS on the monosaccharide composition, molecular weight, thermal properties and the morphological properties. In the scavenging activity against DPPH free radicals, the TPS from extruded tea showed better activity than the untreated one. Extrusion treatment of tea could change the physicochemical properties of TPS and improve the yield and the antioxidant property of TPS, which might be helpful for the tea polysaccharide related products in the food industry.     

Effect of different drying methods on physicochemical properties and antioxidant activities of polysaccharides extracted from mushroom Inonotus obliquus

Inonotus obliquus is a kind of mushroom which has long been used as a folk remedy for curing various diseases such as cancers, heart disease and diabetes in Russian and Eastern Europe. Polysaccharides are one of the main bioactive constituents of Inonotus obliquus with health functions. Three drying methods, freeze drying, hot air drying and vacuum drying methods were comparatively studied on the physicochemical and antioxidant properties of Inonotus obliquus polysaccharide (IOPS) with chemical methods: gas chromatography, size exclusion chromatography, scanning electron micrograph, 1,1′-diphenyl-2-picrylhydrazyl (DPPH) assay, ferric reducing power assay and lipid peroxidation inhibition assay, respectively. Results showed that physicochemical and antioxidant properties of IOPS differed from each other after the treatment of the three drying methods. Compared with hot air drying and vacuum drying methods, freeze drying method resulted in the properties of IOPS with lower molecular weight distribution, a hyperbranched conformation with triple helix, higher antioxidant abilities on DPPH radical scavenging, ferric-reducing power and lipid peroxidation inhibition activity. Freeze drying was a good choice for the preparation of polysaccharides from Inonotus obliquus and could be used to produce antioxidants for food industry.