冬凌草硒多糖的制备及其抗氧化活性分析

以济源冬凌草为原料,水提得到冬凌草多糖,对多糖进行结构修饰制得冬凌草硒多糖.采用UV、FTIR、SEM、TGA、HPLC对冬凌草多糖以及硒多糖结构进行表征;通过1,1-二苯基-2-三硝基苯肼(DPPH)自由基法、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基法、羟基自由基法以及还原能力测定4种方法对冬凌草多糖及其硒多糖的抗氧化活性进行探究.结果表明,冬凌草硒多糖中硒含量为1.35 mg/g.硒化修饰后,冬凌草多糖的基本骨架得到保留,单糖种类未发生改变,但分解温度降低、稳定性下降,多糖形貌也发生明显变化,球状与条状形貌增多,片状形貌减少.在体外抗氧化性实验中,当冬凌草硒多糖质量浓度为1.6 g/L时,对DPPH自由基、ABTS自由基、羟基自由基清除率分别为68.69％、86.90％、45.12％,均强于冬凌草多糖.     

桔梗多糖软模板法制备纳米硒及表征

以桔梗多糖为模板,通过亚硒酸钠与抗坏血酸反应制备纳米硒,探讨多糖浓度,抗坏血酸和亚硒酸钠配比,反应时间,反应温度等条件对产物粒度的大小、形貌的影响,并通过光谱法,透射电镜(TEM)以及X射线衍射(XRD)等手段对产物进行表征。结果表明当多糖浓度为100 mg/L,抗坏血酸和亚硒酸钠物质的量比值为3∶1,40℃条件下反应4 h得到的纳米硒粒径最小,平均粒径约为40 nm左右。     

大黄素-硒(Ⅳ)配合物的合成、表征及抗氧化活性研究

研究了大黄素-硒(Ⅳ)配合物的合成,并对比配体和配合物体外抗氧化活性。采用单因素试验和正交试验研究大黄素-硒(Ⅳ)配合物的最佳合成条件:以无水乙醇为溶剂、n(大黄素)∶n(四氯化硒)=1∶2、pH 3～4、反应温度40～45℃。通过红外光谱法、紫外-可见光谱法和基质辅助激光解吸-飞行时间质谱对大黄素-硒(Ⅳ)配合物的结构进行表征;运用紫外-可见分光光度法测定配体和配合物对DPPH的清除率。结果显示,大黄素-硒(Ⅳ)配合物抗氧化活性相对于配体大黄素有显著提高,大黄素与硒之间存在协同抗氧化作用。     

甘草硒多糖的制备研究

根据有机硒化合物的合成原理,以天然甘草多糖为原料,与亚硒酸硒化,制备甘草硒多糖。利用单因素实验和正交实验探讨最佳工艺条件。实验结果表明,最佳工艺条件为反应温度60℃,反应时间8 h,甘草多糖与亚硒酸的质量比为1∶1,催化剂BaCl2的质量1.0 g。此条件下,甘草硒多糖的收率为27%。红外光谱对甘草硒多糖进行结构表征可知,甘草硒多糖中含有Se O键和Se—C键,实现了甘草多糖的硒化。原子发射光谱对甘草硒多糖中硒质量分数进行测定,甘草硒多糖中硒质量分数为6.59 mg/g。     

抗氧化天然活性多糖

化妆品市场是个充分竞争的市场,也是个同质化比较严重的市场。如何开发化妆品的天然特质,通过对新科技的探索发现,多糖作为一类重要的天然活性高分子,以其独特的抗氧化生物活性,广泛应用于化妆品领域。结合中国本土特色的动植物资源的开发研究,简要介绍了其作用机理以及几种具有应用于化妆品领域潜力的天然活性多糖。     

羧甲基绞股蓝多糖的制备及其抗氧化活性研究

对绞股蓝多糖(GPMP)进行羧甲基化修饰制备了羧甲基绞股蓝多糖(CM-GPMP),采用红外光谱对其结构进行了表征,并对其修饰前后体外抗氧化活性进行了初步研究。结果表明,CM-GPMP和GPMP对DPPH自由基、羟基自由基、超氧阴离子自由基均有一定的清除作用,浓度为2.0 mg.mL-1时,CM-GPMP对上述三种自由基的清除率分别为25.71%、67.30%、29.95%,而GPMP对三种自由基的清除率分别为23.27%、84.93%、15.24%。由此可见,羧甲基化后,绞股蓝多糖清除超氧阴离子自由基的能力有所提高,清除羟基自由基的能力有所降低,而清除DPPH自由基的能力变化不大。     

螺旋藻多糖铁配合物制备、抗氧化及淋巴细胞增殖活性分析

以三氯化铁为原料,通过络合反应,对螺旋藻多糖(SP)进行结构修饰,制得有机铁化合物〔螺旋藻多糖铁(Ⅲ)配合物SP-Fe(Ⅲ)〕。采用FTIR、DSC、TGA、XRD和SEM对其结构进行了表征,采用DPPH(1,1-二苯基-2-三硝基苯肼)自由基法、羟自由基法等5种方法和MTT(四唑盐)法分析了SP和SP-Fe(Ⅲ)的抗氧化活性和淋巴细胞增殖活性的影响。制备的SP-Fe(Ⅲ)中Fe(Ⅲ)质量分数为16.42%±1.17%。采用5轴蛛网图对SP-Fe(Ⅲ)的抗氧化活性进行了综合评价。结果表明,SP-Fe(Ⅲ)相比SP具有较高的抗氧化活性。在模拟人工胃液消化后,随着消化时间的延长,在pH=6.8的人工肠液中释放出的Fe(Ⅲ)质量分数达到83.64%;在31.25×10–3 g/L的质量浓度下,与SP相比,SP-Fe(Ⅲ)配合物对淋巴细胞增殖提高了44.35%。     

羧酸硒醚、二硒醚及相应硒多糖的合成

用NaBH4还原硒粉得Se2-或-SeSe-,然后在碱性水溶液中与氯乙酸、3-氯丙酸和对-溴甲基苯甲酸在室温下反应,制得相应的羧酸硒醚,收率分别为51.9%、62.6%和58.6%,以及丙酸和对甲基苯甲酸二硒醚,收率67.8%和72.1%。用乙酸硒醚分别与邻氨基苯甲酸和水杨酸反应引入其他基团,收率73.6%和69.8%。最后这些合成的化合物通过形成酰氯与麒麟菜多糖中的羟基醚化得到含硒醚或二硒醚结构的新型硒多糖,收率40%~60%。     

纳米硒的制备和表征

硒是一种人体必需的微量元素，随着科技的发展，人们对这种物质的利用也越来越广泛。报道了一种以聚乙烯醇作为软模板制备纳米硒的方法，并对所制得的纳米硒进行了表征，研究了反应物的浓度、温度，以及超声等反应条件对产物形貌及粒径的影响。结果表明，当反应体系中亚硒酸浓度为0．01mol／L、抗坏血酸浓度为0．07mol／L、聚乙烯醇质量分数为1．0％、常温下反应5min后可得到均匀稳定的球形红色纳米硒颗粒，平均粒径约30nm。     

浒苔硒多糖的制备及其活性研究

以自制的浒苔多糖为原料,在硝酸催化下与亚硒酸钠进行硒化反应,制备了浒苔硒多糖。通过单因素实验和正交实验确定最佳合成条件为:亚硒酸钠与浒苔多糖的质量比1.0∶1、反应时间8h、反应温度60℃、硝酸体积分数0.5%,此条件下合成的浒苔硒多糖的硒含量为512.3μg.g-1,其单糖组成为D-甘露糖∶L-鼠李糖∶D-半乳糖醛酸∶D-葡萄糖∶D-木糖=0.01∶0.80∶0.12∶0.65∶0.09(物质的量比)。光谱分析表明产品中含有亚硒酸酯基团。与浒苔多糖相比,浒苔硒多糖清除有机自由基DPPH的能力明显增强,在1.0～10.0mg.mL-1浓度范围内具有一定的还原能力,但清除羟自由基(.OH)的能力变化不大。     

落葵多糖的提取及抗氧化活性的研究

通过正交实验法对落葵多糖的提取工艺进行优化及其清除羟基自由基的活性研究。结果表明,落葵多糖最佳提取工艺条件为:料液比为1∶30,提取时间为60 min,提取次数为3次,乙醇用量为浓缩液的4倍。落葵多糖在一定的浓度范围内对羟基自由基具有很好的清除作用,且有明显的量效关系。     

Preparation,characterization, and antioxidative activity of Bletilla striata polysaccharide/chitosan microspheres for oligomeric proanthocyanidins

Novel oligomeric proanthocyanidins/Bletilla striata polysaccharide/chitosan (OPC/BSP/CTS) microspheres were obtained by spray-drying method. The morphology, size, physicochemical characterization, and in vitro release behavior of the formulation were evaluated. The results of scanning electron microscopy showed OPC-loaded microspheres with considerably wrinkled surfaces and drug-free microspheres with smooth surfaces. Particle-size analysis showed that the diameters of the OPC/BSP/CTS microspheres were 1–5?µm, with uniform distribution (polydispersity below 0.465). Fourier transform infrared indicated the occurrence of a chemical reaction between BSP and CTS. The OPC formed intermolecular hydrogen bonds with BSP/CTS carriers or transmuted amorphous structure. Differential scanning calorimetry displayed the absence of interaction; OPC was only physically encapsulated in the polymer matrix and OPC changed the crystallinity. All the microspheres showed desirable biodegradation rates; the high CTS content retarded their degradation and extended administration times. OPC/BSP/CTS microspheres showed pronounced antioxidant activity than pure OPC. These microspheres can be used as a potential platform to efficiently deliver unstable drugs as a sustained-release oral drug delivery system.     

Preparation,characterization and antioxidant activity of acetylated garlic polysaccharide,and garlic polysaccharide-Zn (II) complex

Garlic polysaccharide (PS) was extracted from garlic by hot-water extraction. Acetylated garlic polysaccharide (AcPS) and garlic polysaccharide-zinc complex (ZnPS) were synthesized. The results of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy analysis showed that the modifications were successful. The antioxidant activities of PS, AcPS, and ZnPS were further investigated in vitro, including scavenging superoxide anion and hydroxyl radicals, antilipid peroxidation capacity, and reducing power. The results showed that the scavenging abilities of AcPS and ZnPS on hydroxyl radical (The IC₅₀ of PS, AcPS, and ZnPS were 2.86, 1.62 and, 1.49 mg/ml, respectively,) and superoxide anion radical (The scavenging rate of PS, AcPS, and ZnPS were 1.5% and 1.8%, and 2.3%, respectively, when concentration was at 1.0 mg/ml.) were stronger than that of PS, and the inhibitory effect of AcPS on lipid peroxidation was significantly stronger than that of PS (The IC₅₀ of PS and AcPS were 1.05 and 0.53 mg/ml, respectively.). It indicated that the acetylation was a favorable way to enhance the antioxidant activity of garlic PS; ZnPS complex could be applied as potential candidate for antioxidant and Zn supplement.     

羊栖菜多糖提取物及其润肤霜的保湿和抗氧化活性

采用超声细胞破碎辅助水提-醇沉法提取羊栖菜多糖(FSF),测定其抗氧化活性和保湿性能,并用其制备润肤霜,体外评价该润肤霜的保湿性能,使用皮肤外涂实验考察该润肤霜对小鼠皮肤抗氧化活性的影响。结果表明:羊栖菜多糖提取物(EFSF)具有较强的自由基清除能力,保湿性能优于甘油;该润肤霜同样具有较好的保湿性能,在干燥环境下198 h的失水率为4.33%,在相对湿度43%环境下198 h的失水率为2.36%;皮肤外涂实验表明,与阴性对照组(仅含基质的润肤霜)、阳性对照组(0.3%熊果苷润肤霜)相比,该润肤霜均可显著增强小鼠皮肤的羟自由基清除能力(403.65 U/mgprot)、超氧阴离子自由基清除能力(810.52 U/gprot)、总抗氧化能力(11.58 U/mgprot)和T-SOD活性(81.11 U/mgprot),显著提高羟脯氨酸含量(43.49 mg/L)以及降低MDA含量(2.12 nmol/mgprot)。     

超声辅助离子液体提取人参多糖工艺及其抗氧化活性

采用超声辅助离子液体提取人参中的人参多糖，通过单因素实验和正交实验确定了人参多糖的最优提取工艺条件；利用苯酚-硫酸法测定提取的人参多糖中总糖含量；以抗坏血酸为对照组，采用1,1-二苯基-2-三硝基苯肼自由基（DPPH·）、羟基自由基（·OH）、2,2′-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基（ABTS·）测定提取的人参多糖的抗氧化活性。结果表明，超声辅助离子液体提取人参多糖的最佳工艺为：选择质量浓度为8 g/L的1-己基-3-甲基咪唑溴盐水溶液为提取溶剂，料液比（人参和离子液体水溶液之比）为1:40（g：mL），在80 ℃下超声辅助提取30 min，人参多糖提取量为172.89 mg/g，提取的人参多糖总糖含量（质量分数）为65.9%。采用高效液相色谱法对纯化后的人参多糖的单糖组成进行测定，得到人参多糖的单糖组成为：甘露糖，核糖，半乳糖醛酸，葡萄糖，半乳糖，阿拉伯糖，岩藻糖，物质的量比为4.8∶6.43∶10.13∶15.71∶0.5∶4.3∶1.1。人参多糖对DPPH·和·OH以及ABTS·具有一定的清除力，其抗氧化能力随质量浓度增大而增强，但弱于抗坏血酸。     

Ultrasound-Assisted Extraction,Preliminary Characterization,and Antioxidant Activity of a Novel Water-Soluble Polysaccharide from Lotus (Nelumbo nucifera Gaertn.) Seeds

Ultrasound-assisted extraction was employed to extract polysaccharides from lotus (Nelumbo nucifera Gaertn.) seeds. Response Surface Methodology was used to determine the optimal extraction conditions of ultrasound power, extraction time, and extraction temperature at 406 W, 7.7 min, and 94°C, respectively. The crude extract was successively purified by chromatography, yielding a major polysaccharide fraction termed LSPS-1. It is a heteropolysaccharide, containing rhamnose, arabinose, glucose, and galactose with a molecular weight of 4484 Da and an α-dominating configuration in pyranose form sugar. Preliminary antioxidant activity test in vitro showed LSPS-1 could potentialize the scavenging effect on hydroxyl radicals in a dose dependent manner.     

Sterculia striata exudate polysaccharide: characterization,rheological properties and comparison with Sterculia urens (karaya) polysaccharide

The exudate polysaccharide from Sterculia striata trees was investigated regarding its composition, structure and rheological properties and metal ion interactions. This polysaccharide contains galactose, rhamnose galacturonic and glucuronic acids as the main monosaccharide components. ¹³C NMR spectroscopy revealed that the anomeric composition is similar to that of Sterculia urens exudates, except for the presence of xylose, not identified in the latter polysaccharide. The empirical stiffness parameter B was determined for S striata (B = 0.043), suggesting that the polysaccharide exists in a semi‐rigid chain conformation, with no conformational change being demonstrated. Deacetylation led to a more flexible polymer chain (B = 0.058). The counter ion affinity of the polysaccharide aqueous solution was determined by intrinsic viscosity measurements, resulting in Al³⁺ > Ca²⁺ > Na⁺. Copyright © 2004 Society of Chemical Industry     

Physicochemical characterization and antioxidant activity of quercetin‐loaded chitosan nanoparticles

Quercetin is an abundant flavonoid in food plants with numerous biological activities and widely used as a potent antioxidant. Being sparingly soluble in water and subject to degradation in aqueous intestinal fluids, the absorption of quercetin is limited upon oral administration. In the present study, chitosan nanoparticles and quercetin‐loaded nanoparticles were prepared based on the ionic gelation of chitosan with tripolyphosphate anions. The encapsulation of quercetin in the chitosan nanoparticles were confirmed by differential scanning calorimetry, X‐ray powder diffractometry, Fourier transformed infrared spectroscopy, ultraviolet‐visible spectrum, and fluorescence spectrum. The morphology of the nanoparticles was characterized by atomic force microscopy. The antioxidant activity of the quercetin‐nanoparticles was also evaluated in vitro by two different methods (free radical scavenging activity test and reducing power test), which indicates that inclusion of quercetin in chitosan nanopaticles may be useful in improving the bioavailabilty of quercetin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008