香菜乙醇提取液的体外抗氧化活性

采用Fenton反应体系产生羟自由基和邻苯三酚自氧化产生超氧阴离子自由基,研究香菜乙醇提取液对两者的清除作用.并以芦丁为时照品,测定其总黄酮含量.结果表明:香菜中总黄酮含量为8.493 mg/g.香菜乙醇提取液对羟自由基和超氧阴离子自由基均有清除作用,半数清除量(IC50)分剐为122.331 mg/L和71.535 mg/L,提取物浓度的添加量在试验范围内与其抗氧化活性呈正相关.     

IN VITRO ANTIOXIDANT AND ANTICANCER ACTIVITIES OF EXTRACTS FROM A FERMENTED FOOD

Solvent extracts were prepared from Manda Enzyme®, one of the fermented health foods, and their activities of radical scavenging and cancer cell growth inhibition were evaluated. Manda Enzyme® was extracted with 55% ethanol, and then fractionated into n‐hexane, chloroform, ethyl acetate, methanol‐soluble and methanol‐insoluble fractions. The antioxidant activities were in the order chloroform > ethyl acetate > other fractions and of each fraction were positively related to the amount of total phenolics and the intensity of brown color. The cancer cell growth inhibitory activities were in the order n‐hexane > chloroform > other fractions. Proliferation of HRT‐18, HCT‐48 and HepG2 human cancer cells was inhibited by the treatment of the n‐hexane fraction of Manda Enzyme® at a concentration of 400 μg/mL to the extent of 75, 89 and 90%, respectively. From these results, it is considered that Manda Enzyme® has chemically different ingredients showing strong antioxidant and anticancer activity in vitro.     

山药多糖结合蛋白质对抗氧化作用的影响

通过测定还原能力、清除H2O2、O2-·、·OH的能力,对未除蛋白质、Sevag法、蛋白酶法去除蛋白质后的3种山药粗多糖的抗氧化性进行比较。结果表明,Sevag法去除蛋白得到的山药粗多糖抗氧化能力最强,除蛋白前的山药粗多糖次之,而用蛋白酶法除蛋白得到的山药粗多糖抗氧化能力最弱。由此可见,山药多糖结合蛋白具有较高的体外抗氧化能力。     

松木层孔菌多糖的提取及抗氧化性研究

首次从松木层孔菌子实体中分离制备3种多糖，并对其抗氧化性进行了研究。结果表明：水提多糖（PSⅠ）、碱提多糖（PSⅡ）、磺化多糖（PSⅢ）均为13构型，单糖纽成以葡萄糖为主（87．43％-90．17％），其次为甘露糖、半乳糖、木糖、核糖。3种多糖分子量分别为230kDa、29kDa、27kDa，均与少量蛋白结合，形成多糖肽，蛋白质含量分别为18．69％、6．72％、2．56％。抗氧化结果表明PSⅡ和PSⅢ的抗氧化效果最好。两种多糖在浓度为1．25mg／mL时，对超氧阴离子自由基的清除率均达到90％以上，在12mg／mL时，羟自由基清除率分别达到81．25％和85．37％，在浓度为10．6mg／mL时，丙二醛生成抑制率均达到65％左右。因此PSⅡ和PSⅢ可作为优良的抗氧化荆应用于食品和保健品领域。     

葡萄皮中花色苷的体外抗氧化研究

研究了花色苷清除DPPH·的能力，并用荧光化学发光法测定了花色苷对活性氧自由基（O2^-、·OH、H2O2）的清除作用。结果表明，该产品对DPPH·、O2^-、·OH、H2O2均具有清除作用，尤其对·OH的清除能力强于抗坏血酸，且清除作用与浓度呈量效关系。     

水溶性绞股蓝皂苷和多糖提取工艺

以绞股蓝为原料,采用热水浸提、超声波强化、大孔树脂层析等方法,对绞股蓝中的主要活性成分皂苷和多耱进行综合提取、分离和纯化.通过正交试验对提取工艺条件进行优化,得出最佳工艺条件为超声波功率20W、作用时间15 min、85℃、pH9.绞股蓝皂苷的得率和纯度分别为3.06%和90.16%;绞股蓝多糖的得率和纯度分别为10.34%和81.52%.     

水溶性红枣多糖提取工艺条件的优化

以红枣为原料,采用水溶法提取红枣中的多糖,研究不同因素对多糖提取率的影响,确定较优提取工艺条件.水溶法提取红枣多糖较优条件为:时间3.5 h,温度95℃,料液比1:12,浸提2次,多糖提取率可达2.53%.     

ANTIOXIDANT PROPERTIES OF POLYPHENOLS EXTRACTED FROM GREEN AND BLACK TEAS

The catechins, including epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG), and the theaflavins, including theaflavin (TF), theaflavin monogallate (TF-1), and theaflavin digallate (TF-2), were extracted from green tea and black tea, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability, superoxide-scavenging efficiency, and lipid oxidation-inhibition ability of the pure compounds listed above as well as epicatechin (EC), carnosol, carnosic acid, and butylated hydroxytoluene (BHT) were investigated.
The DPPH radical-scavenging ability of the catechins was EGCG > ECG > EGC > EC and of the theaflavins was TF-2 > TF-1 > TF. EGCG, ECG, EGC, TF-2, TF-1, and TF showed higher DPPH radical- and superoxide-scavenging abilities than carnosol, carnosic acid, and BHT. EGCG, ECG, EGC, carnosol, and carnosic acid showed higher lipid oxidation-inhibition activity, as measured by the Rancimat method, than BHT and theaflavins.     

碱提绞股蓝水溶性多糖的研究

对碱提绞股蓝（Gynostemma pentaphyllum Makino）水溶性粗多糖进行研究,将绞股蓝进行预处理后干燥,水提取绞股蓝多糖后的残渣进行碱提液,经调pH值、除淀粉、透析、4倍体积无水乙醇醇沉与干燥后得到少量碱提水溶性粗多糖,再经过酶法-Sevage法联合脱蛋白分离纯化得AGM.采用葡聚糖凝胶（G-100）柱层析检测其糖分布情况,结果显示AGM可能由两种多糖组成,其中一种含有结合蛋白质.采用高效液相色谱法分析AGM的单糖组成,结果表明,AGM的单糖组成为：鼠李糖：木糖/岩藻糖（其中至少含有木糖或者岩藻糖中的一种）：阿拉伯糖：葡萄糖：半乳糖=2.43：1.00：3.02：2.59：3.46.     

ANTIOXIDANT ACTIVITIES OF SILK SERICIN FROM SILKWORM BOMBYX MORI

This study was conducted to investigate the free-radical-scavenging activity and antioxidant activity of silk sericin. Silk sericin was prepared from silkworm Bombyx mori and its ability to scavenge hydroxyl, superoxide and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals was determined by Electron Spin Resonance (ESR) and ultraviolet spectrophotometry, respectively. The antioxidant activities of the silk sericin, including lipid peroxidation in the linoleic acid system, reducing power and ferrous-ion-chelating ability, were evaluated. The results showed that silk sericin had a strong scavenging capacity for hydroxyl, superoxide and DPPH radicals. The results also showed that silk sericin had potent antioxidative activity on the peroxidation of linoleic acid. The reducing power and ferrous-ion-chelating ability of silk sericin were significant. These results indicated that silk sericin from silkworm B. mori was a natural antioxidant with potent antioxidative activity.

PRACTICAL APPLICATIONS

Most of silk sericin must be removed during raw silk production at the reeling mill and other stages of silk processing. At present, silk sericin is mostly discarded in silk processing waste water. If silk sericin is recovered and recycled, it can represent a significant economic and social benefit. Silk sericin is a natural macromolecular protein derived from the silkworm Bombyx mori . Silk sericin is useful because of its antioxidant activity. Silk sericin can be cross linked, copolymerized and blended with other macromolecular materials, especially artificial polymers, to produce materials with improved properties. The protein is also used as an improving reagent or a coating material for natural and artificial fibers, fabrics and articles. The materials modified with silk sericin and sericin composites are useful as degradable biomaterials, biomedical materials and functional membranes.     

火棘水溶性多糖PP-A3理化性质研究

对火棘水溶性多糖的PP-A3组分的理化性质进行了研究。结果表明：PP-A3的分子量约为210000u,其主要由阿拉伯糖组成,其中含有少量的葡萄糖和果糖,阿拉伯糖∶葡萄糖∶果糖=1.62∶1∶1.59,此外含氨基酸总量约为0.5%。     

竹黄多糖BSP-1的组成和抗氧化活性分析

对竹黄子实体总多糖进行提取,分离纯化出2种均一的组分BSP-1和BSP-2.采用气相色谱和凝胶渗透色谱研究BSP-1的组成和分子量,并研究其对猪油的抗氧化作用.结果表明:BSP-1分子量为45.64 ku,主要由葡萄糖和甘露糖组成,摩尔比为2.46:1,红外光谱分析表明含有B-糖苷键,体外抗氧化实验证明BSP-1具有一定的抗猪油自动氧化能力.     

仙人掌水溶性粗多糖提取及抗氧化性能研究

研究仙人掌水溶性粗多糖的提取工艺及抗氧化性能。采用单因素试验和L9（3^3）正交试验设计,考察提取温度、时间、料液比等因素对提取率的影响,并采用水杨酸法考察仙人掌粗多糖抗氧化性能。结果表明：温度是影响粗多糖提取的重要因素。优化工艺条件为：提取温度80℃,提取时间1h,固液比为1：60。抗氧化试验表明仙人掌粗多糖有较好的抗氧化活性。     

小麦麦麸碱提物的体外抗氧化作用

研究小麦麦麸碱提物(AHWB)的制备和体外抗氧化活性.小麦麦麸脱淀粉脱蛋白后,碱法水解制备得到3种碱提物(AHWB I、AHWB Ⅱ和AHWBⅢ),考察其对二苯代苦味酰自由基、羟自由基和超氧自由基的清除作用.3种AHWB均能有效清除DPPH自由基和羟自由基.AHWBⅡ能清除超氧自由基,对于DPPH·,3种碱提物的IC50值分别为0.19、0.54、0.39 mg/mL;对于·OH,3种碱提物的IC50值分别为1.13、1.88、1.03 mg/mL,其清除效果与Vc的相近;对于O2-·,AHWBⅡ的IC50值为5.98 mg/mL.因此小麦麦麸碱提物具有较好的抗氧化作用,可作为天然抗氧化剂.