Study on the Free Radical Scavenging Activity of Sea Cucumber (Paracaudina chinens var.) Gelatin Hydrolysate

Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.

STUDIES ON FREE RADICAL SCAVENGING ACTIVITY IN CHINESE SEAWEEDS PART I. SCREENING RESULTS

Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

Evaluation of free radical scavenging activity of various extracts of leaves from Kedrostis foetidissima(Jacq.)Cogn

The present study was aimed to investigate the in vitro free radical scavenging activity of various leaf extracts(aqueous,methanol,acetone chloroform and petroleum ether)of Kedrostis foetidissima.In vitro free radical scavenging activities of the extracts were assessed against DPPH and hydroxyl radicals.The metal chelating activity and reducing power ability of the extracts were also determined.The free radical scavenging activity was found to be high in methanolic extract for DPPH and hydroxyl radicals in a concentration dependent manner followed by chloroform,aqueous,acetone and petroleum ether extracts.The metal chelating activity and reducing power ability was also found to be high in methanolic extract.The difference in scavenging potential of the extracts may be due to variation in the percentage of phytoconstituents extracted in various solvents.Thus the result suggests that the methanolic leaf extract of K.foetidissima could serve as a potential source of antioxidants and can be explored as a therapeutic agent in free radical induced diseases.©2015 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Component Analysis and Free Radicals Scavenging Activity of Physalis alkekengi L. Polysaccharide

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%.

Constituents from Aerial Parts of Bidens ceruna L. and Their DPPH Radical Scavenging Activity

A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucopyranoside（4）, butein-4-methoxyl-4＇-O-β-D-glucopyranoside（5）, butin-7-O-β-D-glucopyranoside（6）, isoquercitrin（7）, and sulfurein（8） was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activitv.

Sonme Factors that Affect the Free Radical-scavenging Activity of Tea Extracts

Some factors that affect the free radical-scavenging activety of two tea extracts were studied in vitro. It was found that concentration of tea extract or heating tea extract or treating with activated carbon and diatomite all had obvious effect on the scavenging activety of green tea extract ,but heating or treating with diaomite had less effect on the scavenging activity of black tea extract. Ascorbic acid, for having synergic effect with tea extracts, could enhance the scavenging activity of tea extracts markedly, and the contrary was cupric ion. Reducing sugars such as fructose and glucose also had some syncrgic effect to tea extracts.

Free Radical-Scavenging Properties and Antioxidant Activity of Fractions from Cranberry Products

Lipid peroxidation inhibition capacity and antiradical activity were evaluated in HPLC fractions of different polarity obtained from two cranberry juices and three extracts isolated from frozen cranberries and pomace containing antho-cyanins, water-soluble and apolar phenolic compounds, respectively. Compounds with close polarities were collected to obtain between three and four fractions from each juice or extract. The cranberry phenols are good free radi-cal-scavengers, but they were less efficient at inhibiting the lipid peroxidation. Of all the samples tested, the intermediate polarity fraction of extract rich in apolar phenolic compounds of fruit presented the highest antiradical activity while the most hydrophobic fractions of the anthocyanin-rich extract from fruit and pomace appeared to be the most efficient at inhibiting the lipid peroxidation. The antioxidant or pro-oxidant activity of fractions increased with the con-centration. The phenol polarity and the technological process to manufacture cranberry juice can influence the antioxidant and antiradical activities of fractions.

Antioxidant Activity of Anthocyanins Extracted from Iraqi <i>Iresine herbstii</i>L. Flowers after Drying and Freezing

Any processing method that maintains the level of compounds known for their health benefits will be of interest to the food industries. Therefore, the effects of vacuum drying, storage and freezing on the anthocyanin content and their antioxidant properties of Iresine herbstii L. flowers were investigated. The results showed that fresh samples (AEFF) had the highest amount of total anthosyanin content (8.31 ± 0.23 mg/g dry matter, expressed as cyaniding 3-glucoside equivalents), followed by 7.17 ± 0.12 mg/g solid content, 13.72% loss of vacuum dried samples (AEDF). In comparison with fresh samples, total anthocyanins in stored samples for two weeks at 5°C (AESF) and frozen samples during 1 (AEZF1) and 3 months (AEZF3) of storage were significantly (P < 0.01) reduced to 6.43 ± 0.24 mg/g solid content, 22.63% loss, 5.65 ± 0.33 mg/g solid content, 32.01% loss and 4.71 ± 0.51 mg/g solid content, 43.33% loss, respectively. Anthocyanins from I. herbstii L. flowers exhibited a dose-dependent (AEFF > AEDF > AESF > AEZF1 > AEZF3, respectively) antioxidant activity against lipid peroxidation in a linoleic acid model system as well as strong reducing power and ferrous ion chelating abilities. Moreover, the anthocyanins extracted were found to show remarkable scavenging activity on superoxide anion radicals, hydroxyl radicals, hydrogen peroxide, nitric oxide radicals and deoxyribose degradation. Based on the results obtained, we can concluded that the Iresine herbstii L. flowers may be valuable natural antioxidant sources and are potentially applicable in both pharmacy and food

桑葚果实、桑葚干酒和桑葚利口酒中酚类化合物的高效液相色谱串联电喷雾二级质谱分析及其抗氧化活性比较

为了解桑葚果酒和桑葚果实在酚类化合物的种类、含量及抗氧化活性之间的差异,该研究以桑葚果实、桑葚干酒和桑葚利口酒为试材,采用高效液相色谱串联电喷雾二级质谱(high performance liquid chromatography-electron spray ionization-mass spectrometry/mass spectrometry,HPLC-ESI-MS/MS)对酚类化合物进行定性定量分析。HPLC-ESI-MS/MS分析结果表明,在桑葚果实、桑葚干酒和桑葚利口酒中均检测到花青素-3-葡萄糖苷和花青素-3-芸香糖苷,而花葵素-3-芸香糖苷和4-丙酮酸-花青素-3-葡萄糖苷分别只在桑葚干酒和桑葚利口酒中被检测到。同时,桑葚干酒和桑葚利口酒中花青素-3-葡萄糖苷和花青素-3-芸香糖苷的含量均显著低于桑葚果实。此外,在桑葚果实中鉴定的8种非花色苷多酚中,仅有4种存在于桑葚干酒和桑葚利口酒中。相较于桑葚果实,桑葚干酒和利口酒中原儿茶素、二氢槲皮素和槲皮素的含量显著升高。桑葚果实DPPH自由基清除能力介于桑葚干酒和利口酒之间。综上,桑葚果酒和桑葚果实中酚类化合物的种类、含量及抗氧化活性之间差异显著。

红曲糟源酶解蛋白肽的功能性评价

【目的】研究不同蛋白酶对红曲糟酶解的效果,并对其酶解液进行功能性评价,为红曲糟源蛋白肽的研发制备提供理论支持。【方法】以提高蛋白含量后的红曲糟为原料,利用碱性蛋白酶、胰蛋白酶、动物蛋白酶、木瓜蛋白酶、菠萝蛋白酶、胃蛋白酶、复配酶制剂F106、酵母抽提酶等不同蛋白酶进行酶解,考察其酶解率、1,1-二苯基-2-三硝基苯肼(DPPH)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基清除抗氧化能力、黄嘌呤氧化酶(Xanthine oxidase,XOD)和血管紧张素转化酶(Angiotensin converting enzyme,ACE)抑制活性等生物活性功能。【结果】蛋白酶解率最高的为动物蛋白酶和胰蛋白酶酶解处理,分别为(71.43±1.03)%和(70.20±0.32)%。DPPH自由基清除抗氧化能力最优的是胃蛋白酶、碱性蛋白酶和酵母抽提酶酶解处理,蛋白肽的半数效应浓度(Median effective concentration,EC50)分别为(2.78±0.34)mg·mL^(-1)、(3.02±0.03)mg·mL^(-1)、(3.24±0.65)mg·mL^(-1);ABTS自由基清除抗氧化能力、XOD抑制活性能力最优的均为胃蛋白酶和碱性蛋白酶酶解液,其蛋白肽的EC50值分别为(1.54±0.07)mg·mL^(-1)、(6.45±0.27)mg·mL^(-1)和(10.71±0.06)mg·mL^(-1)、(17.68±0.04)mg·mL^(-1),二者的XOD半数抑制指数分别为(1.28±0.01)、(1.78±0.03);ACE抑制活性最优的为碱性蛋白酶酶解液和木瓜蛋白酶酶解液,蛋白肽的EC50值均为(0.27±0.01)mg·mL^(-1),半数抑制指数分别为(118.40±3.53)、(98.35±1.95)。【结论】红曲糟源蛋白经不同蛋白酶酶解后的肽段具有不同的生物活性,其中以胃蛋白酶酶解的XOD抑制活性能力较强,碱性蛋白酶和木瓜蛋白酶酶解的ACE抑制活性较优。

无核黄皮果皮总黄酮的提取鉴定及其抗氧化活性分析

旨在从无核黄皮的果皮中提取获得高纯度的总黄酮,定性定量分析常见的类黄酮组分,并考察其体外抗氧化活性。采用超声波辅助醇提及大孔树脂纯化获得总黄酮提取物,以超高效液相色谱-高分辨质谱(Ultra Performance Liquid Chromatography-High Resolution Mass Spectrometry,UPLC-HRMS)检测提取物的黄酮类化合物主要组分及含量,生理生化法离体测试其抗氧化活性。结果表明,75%乙醇,料液比1∶14(g/mL),超声提取60 min,提取2次,总黄酮得率最高,提取液中总黄酮浓度达43.2 mg/mL,纯化后含量达235 mg/g、纯度为86.45%;无核黄皮果皮总黄酮提取物的主要黄酮类组分构成及含量从高到低依次为芦丁、槲皮素、山奈酚和异鼠李素;总黄酮提取物的浓度大于1 mg/mL时,其总抗氧化能力同总黄酮浓度呈正相关关系,并有较强的自由基清除能力。

Syntheses and Crystal Structures of [Na(H_2O)_(1/2)]X and NH_2(CH_2CH_3)_2X and Antioxidant Activity of the Former

In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized and its structure was identified on the basis of NMR, FT-IR and elemental analysis. The assembly of 5,7-dihydroxylflavone-8-sulfonate with diethylamide cation afforded diethylamide 5,7-dihydroxylflavone-8-sulfonate （2, NH2（CH2CH3）2X） which was characterized by FT-IR and elemental analysis. The crystal structures of 1 and 2 were determined by X-ray single-crystal diffraction analysis. The crystal of 1 is of triclinic system, space group P1, with a = 8.5628（13）, b = 12.8916（19）, c = 13.562（2） A, α = 82.494（1）, β = 78.601（2）, γ = 84.033（2）°, C30H20Na2O15S2, Z = 2, Mr = 730.59, V = 1450.3（4） A3, Dc = 1.673 g/cm3, F（000） = 748, p = 0.295 mm^-1, the final R = 0.0641 and wR = 0.1458. The crystal of 2 crystallizes in the triclinic system, space group Pi, with a = 7.689（2）, b = 11.184（3）, c = 11.734（3） A, α = 74.268（3）, βl = 81.751（4）, γ= 87.991（3）°, C19H21NO7S, Z = 2, Mr= 407.43, V= 961.2（4） A3, Dc = 1.408 g/cm3, F（000） = 428, p = 0.210 mm^-1, the final R = 0.0484 and wR = 0.1195. In 1, the three-dimensional structure is organized into organic and inorganic regions; the flavone skeletons are stacked into organic regions by π...π staeking interactions; inorganic regions are generated by Na-O coordination bonds among sulfonate groups, coordinated water molecules and NaI. The sulfonate groups play an important role as a bridge of inorganic and organic regions. One-dimensional chain structure of 2 is extended by N-H…O hydrogen bonds and π...π stacking interactions. Furthermore, the antioxidant activity of 1 was evaluated. The scavenging activity of 1 to DPPH free radical is better than that of the parent compound chrysin.

基于阿伏苯宗-阿魏酸的光释放与抗氧化性能

阿魏酸是一种有效的抗氧化剂,因具有抵抗氧化应激和延缓皮肤衰老性能而被广泛应用于化妆品中.然而,光敏性对其应用提出了挑战.为了克服这一限制,本文开发了一种由阿伏苯宗(AB)和阿魏酸(FA)组成的二元分子.该设计基于阿伏苯宗结构中存在可以光去除的苯甲酰甲基,以保护阿魏酸免受光损伤并保持其抗氧化活性.研究结果表明,FA得以成功释放,AB对FA具有有效的光保护作用.体外实验结果表明,AB-FA分子及其光解产物具有显著的清除自由基活性;而细胞实验结果则证实其较低的细胞毒性和优异的清除活性氧自由基(ROS)能力.

海带多糖羧甲基化修饰工艺优化及其生物活性研究

为优化海带多糖羧甲基化修饰工艺,并研究修饰前后海带多糖的结构与生物活性,该研究通过单因素试验和正交试验对海带多糖羧甲基化修饰进行工艺优化,采用紫外光谱、傅里叶变换红外光谱、高碘酸氧化、刚果红实验对修饰前后多糖进行结构表征,比较修饰前后海带多糖对自由基的清除能力与降血糖活性差异。结果表明,最佳工艺条件为碱化温度50℃、反应时间4.0 h、反应温度65℃、多糖与氯乙酸质量比为3∶7,最高取代度为0.304;红外光谱指征羧甲基化修饰成功,修饰后三股螺旋结构消失,羧甲基化多糖为吡喃型多糖,糖苷键连接方式主要为(1→3)和(1→2,1→4),摩尔比为0.977∶0.023;羧甲基化修饰显著提高了海带多糖对DPPH自由基、羟自由基和超氧阴离子自由基的清除能力,清除率分别提高了7.38%、12.17%、0.78%(P<0.05),但降血糖活性无显著差异,说明在应用羧甲基化修饰促进海带多糖生物活性时可优先从其对自由基的清除能力的角度考虑。

云南主栽核桃和油橄榄16个品种油脂体外抗氧化活性研究

分析云南主栽核桃和油橄榄品种的体外抗氧化活性,为生产核桃和油橄榄的高端复配油提供理论依据。采用试剂盒法对液压榨取核桃油及西班牙橄榄油分析检测系统制备橄榄油脂的总抗氧化能力、羟自由基清除能力、ABTS自由基清除能力、DPPH自由基清除能力以及超氧阴离子清除能力进行分析。结果显示:8个主栽核桃品种的核桃油总抗氧化能力在1.70~10.18(μmol Trolox)·g^(-1)之间,ABTS自由基清除能力在264.04~2224.39(μg Trolox)·g^(-1)之间,DPPH自由基清除能力在388.62~2892.73(μg Trolox)·g^(-1)之间,羟自由基清除率在52.88%~77.77%之间,超氧阴离子清除率在16.25%~39.08%之间,总抗氧化能力、ABTS自由基清除能力及DPPH自由基清除能力品种间差异较大;8个品种油橄榄果油总抗氧化能力在0.73~4.20(μmol Trolox)·g^(-1)之间,ABTS自由基清除能力在153.57~610.91(μg Trolox)·g^(-1)之间,DPPH自由基清除能力在79.20~878.67(μg Trolox)·g^(-1)之间,羟自由基清除率在57.41%~62.83%之间,超氧阴离子清除率在16.69%~38.36%之间。结果表明:云南主栽8个核桃品种抗氧化性能最好品种为‘大姚三台核桃’,其次为‘细香核桃’,抗氧化性能与总酚含量呈显著正相关;油橄榄油脂体外抗氧化活性低于核桃油,其中抗氧化性能最好品种为‘金叶佛樨榄’,其次为‘科拉蒂’,抗氧化性能与总酚含量也呈显著正相关。

桔梗改善皮肤色素沉着的研究

目的:探究桔梗提取物对皮肤色素沉着的功效及其作用机制。方法:利用自由基清除实验研究桔梗提取物对DPPH自由基的清除作用,通过体外酪氨酸酶抑制实验和斑马鱼黑素模型实验研究桔梗提取物改善皮肤色素沉着的功效,最后结合网络药理学探究桔梗活性成分改善皮肤色素沉着的作用机制。结果:桔梗提取物具有显著的抗氧化作用和酪氨酸酶抑制活性,对斑马鱼色素沉着也有显著的改善功效。网络药理学研究发现,桔梗提取物可能通过调节AKT1、TYR和IL-6等细胞靶点及调控PI3K-AKT和脂质代谢等机制通路改善色素沉着。结论:桔梗提取物具有改善色素沉着的功效。

含喹啉杂环席夫碱的合成及清除DPPH自由基活性研究

以水杨醛及衍生物(水杨醛、5-甲基水杨醛、5-甲氧基水杨醛)和2-肼基喹啉为原料,合成了3种含喹啉杂环的腙类希夫碱(L1=水杨醛缩-2-肼基喹啉、L2=5-甲基水杨醛-缩-2-肼基喹啉、L3=5-甲氧基水杨醛-缩-2-肼基喹啉),并用红外、紫外可见-吸收光谱、质谱和核磁共振谱等手段表征其结构,采用1,1-二苯基-2-三硝基苯肼(DPPH)自由基法测试了它们的抗氧化活性,并考察了溶剂、温度、光照对清除DPPH自由基活性的影响。结果表明:以乙醇为溶剂,3种含喹啉杂环的希夫碱对DPPH自由基均具有较好的清除能力,温度、光照对其清除效果影响都较小。

Antioxidant Activity of 50 Traditional Chinese Medicinal Materials Varies with Total Phenolics

This study was designed to determine the total phenolic content of 50 herbs and to examine their antioxidant potential. In the sample preparation, 60% ethanol was chosen as the extraction solvent for the subsequent experiments. Folin-Cicolteau phenol reagent and a colorimetric method were used to determine the total phenolic content of the selected herbs. The result showed that total phenolic content of those herbs ranged from 2 to 185 mg/g. In antioxidant assay, the ferric reducing/antioxidant power (FRAP) values ranged from 2 to 134 mg GAE/g;the IC50 values of DPPH?·, ·OH and ?scavenging were in the range of 0.06 - 5.50 mg/mL, 0.017 - 0.636 mg/mL and 0.050 - 0.681 mg/mL respectively. Flos caryophylli was the exceptant in the ?scavenging assay because there was no linear relation between the concentration and the scavenging percentage. Compared to gallic acid, ascorbic acid and butylated hydroxytoluene (BHT) in antioxidant assay as positive control, the most potential antioxidant herbs were Cacumen platycladi, Radix et Rhizoma rhei, Rhizoma rhodiolae crenulatae, and Rhizoma sanguisorbae with considerable content of phenolics. Especially, a positive and significant correlation was found between the total phenolic content and FRAP value or DPPH· scavenging percentage.

Synthesis of water-soluble C_(60) derivatives and their scavenging free radical activity

Four piperazine-appended [60] fuilerenes (1a-1d) were synthesized and characterized. Their activities of scavenging radical were studied via UV-Vis and EPR. The results indicate that light irradiation is of advantage to increase the activity of scavenging radical.

Crystal Structure, Synthesis and Biological Activity of Ether and Ester <i>Trans</i>-Ferulic Acid Derivatives

The structures of methoxymethyl (E)-3-(4-hydroxy-3-methoxyphenyl)acrylate, 2;(E)-3-(3-methoxy-4-(methoxymethoxy)phenyl)acrylic acid, 3;methyl (E)- 3-(4-(benzyloxy)-3-methoxyphenyl)acrylate, 4;benzyl (E)-3-(4-(benzyloxy)- 3-methoxyphenyl)acrylate, 6;and (E)-3-(4-(benzyloxy)-3-methoxyphenyl)- acrylic acid, 7;were established by spectroscopic and X-ray diffraction studies. Structure 2 is a new com-pound. Compounds with free phenolic hydroxyls v.gr. methyl (E)-3-(4-hydroxy-3-methoxyphenyl)acrylate 1, 2 and ben-zyl(E)-3-(4-hydroxy-3-methoxyphenyl)acrylate 5, showed scavenging free- radical and antioxidant activity while moderate scavenging free-radical was observed in compound 3. Moderate inhibition of lipid peroxidation was observed for 7. Compound 5 exerted significant inhibition of cell growth in PC-3, K562 tumor cell lines and 4 exhibited the largest cytotoxic effect upon the K562 cell line.