猪皮胶原蛋白抗氧化肽的分离纯化及体外抗氧化活性研究

采用碱性蛋白酶对猪皮胶原蛋白进行酶解,制备抗氧化肽。为了得到抗氧化活性高且纯度高的抗氧化肽,本实验采用多种体外抗氧化评价体系研究超滤获得的各分子质量段猪皮胶原蛋白抗氧化肽的体外抗氧化活性;依次采用离子交换色谱、凝胶色谱对猪皮胶原蛋白酶解液进行分离纯化。结果显示:超滤分离获得5~10ku的抗氧化肽较其他分子量范围的抗氧化肽具有较好的抗氧化活性;采用离子交换色谱、凝胶色谱两种分离方法分步分离能达到较好的分离纯化效果,离子交换色谱分离得到7个组分,其中组分P1对O-2·清除率最高,多肽浓度为0.85mg/mL时,清除率为46.30%,IC50值为1.24mg/mL;该组分经过凝胶色谱分离后得到2个组分,其中组分P1-B对O-2·清除率最高,多肽浓度为0.9mg/mL时,清除率为49.43%,IC50值为0.98mg/mL。     

诺邓火腿抗氧化肽的分离纯化与鉴定

提取诺邓火腿抗氧化肽,经过Sephadex G-25凝胶色谱进行分离纯化,对各组分进行体外抗氧化试验(清除·OH、清除DPPH自由基、螯合Fe~(2+))研究抗氧化活性;将抗氧化活性最强的组分经葡聚糖凝胶G-15(Sephadex G-15)凝胶色谱再次分离纯化,最后对抗氧化活性最强的组分通过基质辅助激光解析串联飞行时间质谱仪(MALDI-TOF-MS)对抗氧化肽进行测序鉴定。试验结果:诺邓火腿抗氧化肽经Sephadex G-25凝胶色谱进行分离纯化后得到4个组分(A、B、C和D),其中组分C的抗氧化活性最强,质量浓度为1 mg/mL时,·OH清除率、DPPH自由基清除率和Fe~(2+)螯合率分别达到50.01%、48.32%和34.37%,与其他组分(A、B和D)相比,差异极显著(p0.01);组分C经Sephadex G-15凝胶色谱分离纯化的5个组分(C_1、C_2、C_3、C_4和C_5),其中C_3组分抗氧化活性最强,质量浓度为1 mg/m L时,·OH清除率、DPPH自由基清除率和螯合Fe~(2+)分别达到73.01%、51.21%和65.23%,与其他组分(C_1、C_2、C_4和C_5)相比,差异极显著(p0.01);通过MALDI-TOF-MS对C_3组分抗氧化肽进行测序鉴定,得到抗氧化肽序列。     

玉米胚芽脱脂粕水解物的分离及抗氧化性质研究

文章主要采用超滤、凝胶层析对脱脂玉米胚芽粕水解物进行分离,评价玉米胚芽粕水解物及分离所获得的组分的抗氧化活性。结果表明,玉米胚芽粕水解液经超滤分级后,筛选得到分子量6kDa的组分抗氧化活性较强,进一步采用Sephadex G-15凝胶层析分离,得到G1、G2、G3、G4 4个抗氧化活性组分,其中G2组分抗氧化活性最强。玉米胚芽粕水解物具有较强的清除超氧阴离子自由基、羟自由基、DPPH·能力、抗油脂氧化能力和还原力。     

河蚬肉抗氧化肽的分离及活性研究

目的:为制备具有抗氧化活性的河蚬肉抗氧化肽。方法:河蚬肉酶解液经膜分离后,采用Sephacryl S-100 HR凝胶层析柱进行分离,得到抗氧化性最强的组分经CM Sepharose FF离子交换层析柱进一步分离,并对各组分的体外抗氧化活性进行测定。结果:经Sephacryl S-100 HR凝胶层析柱分离得到5个活性组分A、B、C、D和E,其中组分C的抗氧化活性较强,其总抗氧化能力A_(700 nm)、羟自由基清除率和DPPH自由基清除率分别为1.79、83.33%和26.35%。组分C经CM Sepharose FF离子交换层析柱进一步分离得到2个活性组分C1和C2,其中C2的抗氧化活性最强,总抗氧化能力A_(700 nm)、羟自由基清除率和DPPH自由基清除率分别为2.03、92.34%和35.94%。结论:河蚬酶解液抗氧化肽的羟自由基清除能力突出,该研究为河蚬肉抗氧化肽的开发提供理论技术依据。     

金针菇子实体多糖的抗氧化活性的研究

新鲜金针菇子实体匀浆后用热水浸提,乙醇沉淀,Sevage法去蛋白,得到粗多糖.粗多糖经过DEAE52-纤维素柱层析后得到2个组分A1和A2,组分A2再经SephadexS-200凝胶柱层析证实为单一组分,组分A2的抗氧化活性测定结果显示金针菇多糖具有抗氧化活性,且抗氧化活性随浓度升高而升高.研究结果为金针菇的进一步开发和利用提供参考.     

桦褐孔菌多糖的分离纯化及其抗氧化活性测定

以桦褐孔菌为原料,测定其化学组分,并采用水提醇沉法提取桦褐孔菌粗多糖（IOP）。将获取的桦褐孔菌粗多糖进行脱蛋白、脱色素的初步纯化,然后利用DEAE-52纤维素层析柱及Sephadex-100凝胶柱对多糖提取液进行分离纯化,通过抗氧化活性筛选出活性较高的多糖组分,并通过高效液相色谱分析多糖组分的纯度。实验结果表明,桦褐孔菌子实体的化学成分组成丰富,其中多糖13.10%±0.31%、还原糖4.21%±0.40%、蛋白质2.70%±0.71%、灰分9.60%±0.31%。通过对桦褐孔菌粗多糖脱蛋白、脱色素的试验方法进行筛选,得到聚酰胺层析法为最佳的脱除方法。蛋白质的脱除率为93.1%、脱色率为75.8%,多糖的保留率为90.3%。IOP经过DEAE-52纤维素柱层析后得到四个单糖组分:IOP-1、IOP-2、IOP-3、IOP-4。对四个多糖组分进行抗氧化实验发现,IOP-2对DPPH自由基的清除率最高,清除率为81.9%。IOP-2经过Sephadex-100层析柱后获得两个多糖组分:IOP-2a、IOP-2b。对比其抗氧化活性,筛选出活性较高的多糖组分为IOP-2a。采用高效液相色谱法鉴定多糖组分IOP-2a,只检查出一个对称峰,说明IOP-2a为均一性多糖。     

黑树莓花色苷分离、纯化与抗氧化活性

采用AB-8大孔树脂和硅胶柱层析技术纯化并分离黑树莓花色苷,分别通过DPPH自由基、ABTS自由基和羟自由基清除试验评价花色苷组分的抗氧化活性。结果表明:经过大孔树脂纯化后的花色苷的纯度从17.18%提高到85.21%,得率为0.60%;硅胶柱层析参数为洗脱液配比为正丁醇∶乙酸∶水的体积比为4∶2∶0.5,流速为0.5 mL/min,树莓花色苷粗品与硅胶的质量比为1∶550;得到黑树莓花色苷产物组分分别为BRA1和BRA2,纯度分别为94.53%和92.14%。组分BRA1的抗氧化活性优于组分BRA2,两者均呈现出良好的抗氧化活性。     

桂皮抗氧化成分的研究

经过筛选试验发现,我国作为香料及中药的桂皮(Cassia)对油脂有很强的抗氧化效能。栓皮的甲醇浸膏用溶剂分离法分离,所得各组分用烘箱贮藏法测定其抗氧化活性,底物为猪油,结果显示氯仿组分有很强的抗氧化活性。用梯度洗脱柱色谱及真空液相色谱分离氯仿组分,烘箱贮藏法测定其抗氧化效能发现,真空液相色谱Ⅴ3号组分(TLC方法鉴定为纯物质)有很强的抗氧化效能,用UV.IR.~1HNMR对其结构进行分析,推断其为萜烯类物质。     

猪肚菇子实体多糖的分离纯化及抗氧化活性测定

目的：研究多猪肚菇子实体多糖的抗氧化活性。方法：用热水浸提新鲜猪肚菇子实体,乙醇沉淀多糖,Sevag 法去除多糖中的蛋白,DEAE-52 纤维素柱层析、Sephadex S-200 凝胶柱层析进一步纯化,然后进行抗氧化活性测定。结果：DEAE 柱层析纯化后得到两种多糖组分A 和B,Sephadex S-200 凝胶柱层析证实A 为单一组分,组分A 的抗氧化活性测定结果显示其具有抗氧化活性,且抗氧化活性随其质量浓度的升高而升高。结论：分离纯化后的猪肚菇多糖具有抗氧化活性,且活性呈现剂量效应,随质量浓度升高而升高。     

薏米中多酚化合物的分离纯化及抗氧化活性分析

利用葡聚糖凝胶将薏米中两类多酚类物质进行分离纯化,从而得到6个不同的组分。采用Folin-Ciocalteu法测定该6个组分总酚含量,采用氧自由基吸收能力(oxygen radical absorbance capacity,ORAC)、过氧化氢自由基清除能力(peroxyl radical scavenging capacity,PSC)和细胞内抗氧化能力(cellular antioxidant activity assay,CAA)分析法测定所得6个组分抗氧化能力。在所得的6个组分中选择抗氧化活性最强的3个组分进行半制备,可制得4种薏米多酚纯化物,并测定其4种纯化物的抗氧化活性。结果发现,所分离的6个组分中,薏米中的多酚主要存在于组分2、组分3及组分5中,其总酚含量分别为(30.56±2.25)、(17.40±2.76)、(25.18±1.10)mg GAE/100 g薏米粉末,结合型酚类化合物占薏米总酚含量1/3以上。组分2、组分3及组分5薏米多酚的抗氧化能力较强。经过半制备液相得到的4种多酚纯化物质分别为N_1,N_5-双(对香豆酰)亚精胺、对香豆酸、阿魏酸及芦丁,其中N_1,N_5-双(对香豆酰)亚精胺为游离型多酚的主要物质,而阿魏酸为结合型多酚的主要物质,但在游离型多酚中也有少许存在。4种酚类化合物均具有强抗氧化活性,是薏米中多酚类物质发挥抗氧化作用的主要活性成分。     

柚皮提取物的抗氧化作用研究

用有机溶剂从柚皮中提取、硅胶柱洗脱、薄层色谱鉴别,分离出具有强抗氧化活性的组分C3－1,研究了pH值和温度对其抗氧化活性的影响,其最适作用pH值为6.0,对温度的稳定性好。研究了其抗氧化增效剂,维生素C和柠檬酸具有协同增效作用。该组份对棕榈油和猪油酸败的抑制作用强于BHT。     

藜蒿中黄酮类物质抗氧化作用的研究

采用Rancimat法对藜蒿提取物的抗氧化作用进行了探讨。研究表明:藜蒿提取物对油脂具有明显的抗氧化作用,且具有剂量效应关系;在乳化体系中提取物的抗氧化效果比在油体系中强;提取物与BHT、PG相比较,提取物浓度达0.10%时的抗氧化活性超过0.02%BHT,而小于0.02%PG;柠檬酸、酒石酸、抗坏血酸对藜蒿提取物表现出较强的协同增效作用。     

Antioxidative properties and stability of ethanolic extracts of Holy basil and Galangal

The aims of this work were to assess the influence of concentration, heat treatment, and pH value on antioxidant activity of ethanolic extracts obtained from Holy basil (Ocimum sanctum Linn) and Galangal (Alpinia galanga). The antioxidative properties were evaluated. The ethanolic extracts of Holy basil and Galangal showed good heat stability (80 °C, 1 h). At neutral and acidic pH, Holy basil extracts had high antioxidative stability, whereas Galangal extracts showed higher antioxidative stability at neutral than at acidic pH ranges. Antioxidant activity of both extracts at neutral pH was higher than at acidic pH ranges. Holy basil and Galangal extracts exhibited strong superoxide anion scavenging activity, Fe²⁺ chelating activity, and reducing power in a concentration-dependent manner. Antioxidant activity of both extracts correlated well with reducing power. Furthermore, ethanolic extracts of Holy basil and Galangal acted as radical scavenger and also as lipoxygenase inhibitor.     

提取溶剂对生姜抗氧化性能影响的研究

本文采用几种溶剂并结合微波技术浸提生姜中的抗氧化物质;研究了不同溶剂提取物对猪油的抗氧化效果,其抗氧化性能大小排序为:乙醇提取物> 乙醇微波提取物> 乙酸乙酯提取物> 正己烷提取物> 丙酮提取物。并进一步探讨了提取物浓度与抗氧化性能的关系。     

The effects of stabilised extracts of sage and oregano on the oxidation of salad dressings

The antioxidative activity of sage and oregano either dissolved in ethanol or homogenised with olive oil as a carrier was evaluated in salad dressings. These samples were stored in the dark at ambient temperature and at 40 °C, and with light exposure at ambient temperature. Sage and oregano extracts were encapsulated in liposomes by ultrasonification or microfluidisation, and their structures confirmed by microscopic examination and dye-marker carboxyfluorescein. The antioxidant effect of these preparations was evaluated in salad dressings during storage in the dark at ambient temperature, at 40 °C and at 60 °C. The oxidation process was followed by measuring the formation of conjugated diene hydroperoxides as primary and hexanal as secondary oxidation products, as well as changes in the compositions of fatty acids and tocopherols. Oregano and sage extracts homogenised with olive oil as a carrier showed higher antioxidative effects than these extracts dissolved in ethanol during storage in the dark at ambient temperature and at 40 °C. Exposure of salad dressings to light changed the antioxidative effect of plant extracts into a pro-oxidative effect. The preparation of liposomes by microfluidisation showed higher encapsulation efficiency and more homogeneous vesicles than liposomes prepared by ultrasonification. Sage liposomes prepared by micofluidisation showed high antioxidative effects similar to butylated hydroxytoluene liposomes in salad dressings during storage in the dark at ambient temperature and at 40 °C.     

ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF EDIBLE MUSHROOMS

The antioxidative potency of commercially available mushrooms in Taiwan was studied. The free radical scavenging activities of these mushrooms were demonstrated by using the DPPH method. The antioxidative activities of ethanol extracts of various mushrooms in an emulsified corn oil (o/w) system at 60C were compared. The addition of test compounds in corn oil emulsions significantly extended the induction period of lipid oxidation. The order of inhibitory activity of mushroom extracts on oxidation in emulsion system was Agaricus bisporus > Hypsizigus marmoreus > Volvariella volvacea > Flammulina velutipes > Pleurotus eryngii > Pleurotus ostreatus > Hericium erinaceus > Lentinula edodes. In the thermal oxidative stability test, using lard, the order of antioxidative activity of test materials showed similar tendencies, except for the extract of Lentinula edodes.     

Antioxidant activity of Egyptian Eucalyptus camaldulensis var. brevirostris leaf extracts

Leaves from Eucalvptus camaldulensis var. brevirostris trees, planted in the Nile delta in Egypt, were examined for the antioxidant activity of their nonvolatile compounds. The extracts obtained by ethanol digestion and by supercritical fluid extraction (SFE; CO2 with 15% ethanol) showed the most promising antioxidative activities. In order to identify the most active compounds, both extracts were subjected to a semipreparative reversed-phase HPLC separation, the main fractions were collected, tested for antioxidative activity and analysed by different chromatographical and spectroscopical methods for identification of the most relevant compounds. Gallic and ellagic acid were found to be the prevailing antioxidants in the ethanolic extract. The main two compounds of the SFE extract with antioxidative activity revealed to be flavones. To a high degree of probability they were identified as 5-hydroxy-7,4'-dimethoxy flavone and 5-hydroxy-7,4'-dimethoxy-8-methyl flavone, respectively. The extracts obtained by ethanoldigestion were dried and administered to rats for toxicity evaluation (up to 3 g/kg body weight). No mortality was observed which indicates a very low lethality of the tested extract.     

Effects of alkaline and heat treatment on antioxidative activity and total phenolics of extracts from Hsian-tsao (Mesona procumbens Hemsl.)

The effects of processing conditions on the antioxidative activity and total phenolics content of extracts from Hsian-tsao were investigated. Hsian-tsao was extracted with boiling water for 0.5–3 h by the addition of 0 to 1.5% of Na₂CO₃ or NaHCO₃ solution. A higher content of total phenolics and stronger antioxidative activity were found in the extracts from Hsian-tsao treated with Na₂CO₃ at concentrations of 0.1–0.3% under heating for 2 h. The antioxidative activity, the scavenging activity on DPPH radical and superoxide anion, and the content of total phenolic compounds of Hsian-tsao extracts decreased with increases in the alkaline concentration and heating time. The antioxidative activity and the scavenging effects on DPPH radical and superoxide anion of Hsian-tsao extracts were highly correlated with the total phenolic contents of the extracts.     

蜂胶提取物对菜籽油抗氧化性的研究

蜂胶富含黄酮,具有较好的抗氧化功能。采用微波辅助提取技术对蜂胶中的抗氧化物质进行了优化提取,研究了提取物在菜籽油中的抗氧化性能,并对其有效的抗氧化成分进行了分析和初步研究。研究结果表明,蜂胶提取物具有较好的抗氧化作用,其抗氧化性优于茶多酚,与VC相近。     

Properties of Extract from Okara by Its Subcritical Water Treatment

Okara was treated with subcritical water at temperatures ranging from 170 to 260°C for various times. After clarification, the extracts were analyzed for their protein and carbohydrate contents, DPPH radical scavenging activity, and antioxidative activity. The carbohydrate content significantly decreased with the increasing treatment temperature and time. The protein content, however, increased with the increasing treatment temperature and slightly decreased with a heating time longer than 10 min. The extract obtained from the subcritical water treatment at 240°C for 5 min, which would be used to evaluate the antioxidative activity, provided the relatively highest radical scavenging activity and the activity tended to decrease with the prolonging heating time and temperature. The extract also exhibited a suppressive activity to the autoxidation of linoleic acid with the increasing weight ratio of the extract to linoleic acid. The results clearly showed okara still contained highly valuable substances for human consumption.