连翘叶抗氧化谱效相关质量评价研究

建立连翘叶抗氧化谱效相关质量评价指标,探索连翘叶抗氧化主要活性成分。用高效液相色谱(HPLC)法研究18个不同产地连翘叶提取物的指纹图谱;分别采用1,1-二苯基-2-苦肼基(DPPH·)清除法和Folin-Ciocalteu法测定了连翘叶的抗氧化活性和总酚含量。通过抗氧化活性和总酚含量的双变量相关分析,结果显示连翘叶抗氧化活性与其总酚含量具有较高的相关性;通过主成分、双变量相关、多元线性回归进一步分析了连翘叶抗氧化的谱效关系,结果显示连翘叶中主要有3个化学成分与其抗氧化活性之间存在着明显的关联性。本研究结果为连翘叶抗氧化活性的评价提供了依据。     

大血藤抗氧化及抗菌活性研究

本文评价了大血藤乙醇提取物和石油醚、二氯甲烷、乙酸乙酯和水部位的体外抗氧化和抑菌活性以及与总酚含量的相关性。采用清除DPPH自由基法、Fe3+还原力法评价了各部位的抗氧化活性,采用纸片扩散法评价各部位的抑菌活性。采用Folin-Ciocalteu法测定各部位总酚含量,并采用HPLC-UV解析活性部位物质基础。结果表明,水部位清除DPPH能力最强(IC505.53μg/m L),优于对照组Vc,其它部位顺序为乙酸乙酯部位乙醇提取物二氯甲烷部位石油醚部位,还原Fe3+的能力顺序与此相同。总酚含量与抗氧化活性正相关。石油醚部位、二氯甲烷部位、乙酸乙酯部位有中等强度的抑制革兰氏阴性菌作用。表明大血藤可能会成为有价值的天然抗氧化和抗菌资源。     

红花桑寄生叶提取物的抗氧化活性及酚类物质分析

采用DPPH法、TEAC法、FRAP法对红花桑寄生叶不同溶剂提取物的抗氧化活性进行体外评价,并测定其总酚、总黄酮含量。结果表明,溶剂种类对红花桑寄生叶提取物的得率、总酚、总黄酮及抗氧化活性影响显著。在3种评价方法中,不同溶剂提取物的抗氧化活性均表现出不同程度的量效依赖关系。3种溶剂提取物的抗氧化活性强弱依次为丙酮提取物 >甲醇提取物 >水提取物,其中80%丙酮提取物(总酚含量最高,达276.83mg/g)抗氧化活性最强,清除DPPH自由基能力EC₅₀值为0.247,FRAP值(FeSO₄ mmol/100g)为115.81,浓度为1.0mg/ml时,TEAC值为2.04。     

香露兜叶的抗氧化活性(英文)

本文评价了香露兜叶的乙醇提取物以及石油醚、乙酸乙酯、正丁醇和水相组分的抗氧化活性。在体外测定了提取物和组分的总抗氧化活性,二苯代苦味肼基(DPPH)自由基清除活性,超氧阴离子自由基清除活性和铁离子还原能力,并利用分光光度法测定了其总酚和总黄酮的含量。结果表明,所有的提取物和组分均表现出抗氧化和自由基清除活性。抗氧化活性的大小如下:正丁醇部分>乙酸乙酯部分>乙醇提取物>水部分>石油醚部分。总酚含量的顺序和其相似,说明提取物和组分中的酚类化合物使其具有抗氧化活性。香露兜叶提取物可能会成为有价值的天然抗氧化资源,并将在保健品和食品中得到应用。     

蜜蜂巢脾抗氧化活性与抗菌活性的研究

以意蜂巢脾和中蜂巢脾为研究材料,分别采用水提法和醇提法处理,对获得的4种提取物,以DPPH.法测定自由基清除能力,福林酚法测定总酚含量,琼脂扩散法测定其对金黄色葡萄球菌和大肠杆菌的抑菌半径。结果表明,巢脾提取物具有一定的抗氧化活性和抑菌活性,且含有丰富的酚类化合物。除了对大肠杆菌的抑制作用外,巢脾水提液效果优于巢脾醇提液;除DPPH.清除能力外,意蜂巢脾效果优于中蜂巢脾效果;生物学活性呈现浓度依赖效应。本研究为巢脾在中医药领域的应用提供了一定的解释,并证明了巢脾是一种潜在的天然生物资源。     

三七总皂甙和银杏叶提取物预防急性氧中毒的实验研究

目的:研究三七总皂甙和银杏叶提取物对急性氧中毒的预防作用及其可能机制.方法:分别给小鼠连续腹腔注射三七总皂甙和银杏叶提取物5 d后,在500kPa高压氧中暴露60 min,观察惊厥潜伏期、惊厥次数、惊厥间隔时间等指标;另外测定高压氧暴露15 min后脑组织中活性氧单位、脂质过氧化物、一氧化氮、谷胱甘肽的含量和过氧化氢酶、谷胱甘肽过氧化物酶、单胺氧化酶的活性.结果:三七总皂甙和银杏叶提取物可以明显延长氧惊厥潜伏期和惊厥间隔时间,减少惊厥次数;降低高压氧暴露后脑组织中脂质过氧化物、一氧化氮的含量,使活性氧单位、谷胱甘肽含量和谷胱甘肽过氧化物酶活性保持在较高的水平;对过氧化氢酶和单胺氧化酶活性的影响则不显著.结论:三七总皂甙和银杏叶提取物可以有效预防急性氧中毒,其机制可能与它们的抗氧化活性有关.     

石韦提取物抗氧化及抑制亚硝化作用研究

研究石韦不同溶剂提取物的总酚、总黄酮含量和抗氧化及抑制亚硝化活性,并分析其相关性。采用福林酚比色法和硝酸铝络合分光光度法分别测定各提取物中总酚、总黄酮的含量,以DPPH法、ABTS法和普鲁士蓝法分别测定各提取物的自由基清除能力和铁离子还原力,采用盐酸萘乙二胺法和α-萘胺法分别测定石韦各提取物对亚硝酸盐的清除率和对亚硝胺合成的阻断率,采用Pearson法分析总酚、总黄酮含量与抗氧化及抑制亚硝化活性的相关性。结果表明:石韦不同溶剂提取物的总酚和总黄酮含量存在显著性差异,其中正丁醇提取物的总酚、总黄酮含量均最高,分别为29.85±2.15和37.23±2.41 mg/g。各提取物均具有较强的抗氧化和抑制亚硝化活性,以正丁醇提取物的效果最显著,其DPPH自由基清除能力(IC_(50)=44.14±1.21μg/mL)、ABTS自由基清除能力(IC_(50)=97.47±12.10μg/mL)和还原能力(822.08±24.82μmoL Vc/g),以及对亚硝酸盐的清除能力(IC_(50)=7.071±0.231 mg/mL)、对亚硝胺合成的阻断能力(IC_(50)=15.010±1.224 mg/mL)均最强,并显著强于其他提取物(P0.05)。相关性研究显示,石韦各提取物的抗氧化活性和抑制亚硝化活性与其总酚和总黄酮含量呈显著正相关(P0.05),表明总酚类和总黄酮类物质是石韦发挥作用的物质基础。通过对石韦不同提取物的总酚和总黄酮含量的测定、抗氧化和抑制亚硝化作用评价及相关性分析,为石韦的进一步开发利用提供实验数据和参考依据。     

蓝莓果渣提取物总酚含量及抗氧化活性研究

研究了蓝莓果渣提取物总酚含量及其抗氧化活性。分别采用水、40%乙醇及纤维素酶辅助乙醇超声提取蓝莓果渣,并用Folin-Ciocalteu试剂对3种提取物的总酚含量进行评估;并采用DPPH清除实验及O2—.清除实验对3种提取物的抗氧化活性进行研究。实验结果表明,纤维素酶辅助超声提取蓝莓果渣的总酚含量最高,可达425.36±15.21 mg GAE.100 g-1DW,远远高于水提物(169.46±9.75 mg GAE.100 g-1DW)及醇提物(218.39±12.54mg GAE.100 g-1DW)中的总酚含量。且纤维素酶辅助乙醇超声提取物对DPPH的清除能力为2.67±0.13 gVc.100 g-1DW,对O—.2的清除能力2.48±0.14 g Vc.100 g-1DW,明显好于醇提物及水提物抗氧化活性。     

新疆不同红枣品种的总酚含量和抗氧化能力比较

为了研究新疆红枣的遗传多样性,寻找抗氧化能力较强的功能性红枣品种,为保护利用红枣资源提供基础,用Folin-Ciocalteau法测定了7个品种红枣甲醇提取液中的总酚含量,采用体外法评价了红枣甲醇提取物的总抗氧化能力及对DPPH·和羟基自由基(·OH)的清除能力。结果表明:7个参试红枣品种都具有强抗氧化性,并且大多数品种间差异显著,其中哈密大枣、骏枣、灰枣的抗氧化能力较强;不同品种间的总酚含量差异较大,变化值为751.25 mg/100g,其中哈密大枣中含量最高是1 837.48 mg/100g,新疆小圆枣的总酚含量最低为1 086.23 mg/100g;相同品种中果肉和果核间总酚含量差异较大,果肉总酚含量约为果核的6倍。各种抗氧化指标与总酚含量呈显著正相关,酚类物质是红枣抗氧化的重要物质基础之一。     

显齿蛇葡萄抗氧化活性与主要成分相关性研究

探究不同显齿蛇葡萄提取物抗氧化活性及其与多酚、黄酮、二氢杨梅素的相关性。实验分别用水和乙醇溶液提取制备四种显齿蛇葡萄提取物,并测定总多酚、总黄酮、二氢杨梅素含量。利用·OH、O_2~-·、DPPH自由基清除实验以及还原力实验共四种体系,评价各提取物抗氧化活性;使用SPSS进行活性与成分的Pearson相关分析,并建立回归方程模型。结果显示,四种提取物均具有显著抗氧化活性,但差异明显,综合以二氢杨梅素提取物最强,醇提物居中,水提物最弱。Pearson相关分析显示不同提取物的抗氧化活性与总多酚、总黄酮、二氢杨梅素含量呈显著正相关(P 0.01),表明总多酚、总黄酮、二氢杨梅素均是显齿蛇葡萄中主要抗氧化功效因子,但不同抗氧化体系中三种成分的影响程度表现各异。     

Potential of Ginkgo biloba L. leaves in the management of hyperglycemia and hypertension using in vitro models

Leaves from four different Ginkgo biloba L. trees (1 and 2 – females; 3 and 4 – males), grown at the same conditions, were collected during a period of 5 months (from June to October, 2007). Water and 12% ethanol extracts were analyzed for total phenolics content, antioxidant activity, phenolic profile, and the potential in vitro inhibitory effects on α-amylase, α-glucosidase, and Angiotensin I-Converting Enzyme (ACE) enzymes related to the management of diabetes and hypertension. The results indicated a significant difference among the trees in all functional benefits evaluated in the leaf extracts and also found important seasonal variation related to the same functional parameters. In general, the aqueous extracts had higher total phenolic content than the ethanolic extracts. Also, no correlation was found between total phenolics and antioxidant activity. In relation to the ACE inhibition, only ethanolic extracts had inhibitory activity.     

Antitumoral and antioxidant effect of essential oils and <Emphasis Type="Italic">in vitro</Emphasis> antioxidant properties of essential oils and aqueous extracts from <Emphasis Type="Italic">Salvia pisidica</Emphasis>

The aim of the work was to investigate antitumoral effect of essential oils on cancer cells and their possible protective (antioxidant) effects against hydrogen peroxide-induced cytotoxicity. Also, in vitro antioxidant properties of essential oils and aqueous extracts from wild form and cultivated form of Salvia pisidica were compared.     

Antioxidant properties of essential oils from lemon, grapefruit, coriander, clove, and their mixtures

Antioxidant properties of individual essential oils from lemon (Citrus limon L.), pink grapefruit (Citrus paradise L.), coriander (Coriandrum sativum L.), and clove (Caryophyllus aromaticus L.) buds and their mixtures were studied by capillary gas-liquid chromatography. Antioxidant activity was assessed by oxidation of the aliphatic aldehyde hexanal to the carboxylic acid. The lowest and highest antioxidant activities were exhibited by grapefruit and clove bud essential oils, respectively. Mixtures containing clove bud essential oil also strongly inhibited oxidation of hexanal. Changes in the composition of essential oils and their mixtures in the course of long-term storage in the light were studied. The stability of components of lemon and coriander essential oils in mixtures increased compared to individual essential oils.     

四味镇痛中药对内腓肽降解酶作用的实验研究

目的 :研究四味镇痛中药对内腓肽降解酶的作用。方法 :从大鼠的肾脏制备含有内腓肽降解酶的物质 ,建立内腓肽降解酶活性检测模型 ;并用此模型观察四味镇痛中药提取物对内腓肽降解酶特别是对中性内肽酶活性 (NEP2 4 .11)的抑制作用。结果 :(1)钩藤和羌活的水提物显示很强的NEP2 4 11酶抑制作用 ;(2 )无论是有机提取物还是水提物 ,延胡索和川芎对NEP2 4 11的抑制作用都弱于钩藤和羌活 ;(3)钩藤和羌活不仅是氨肽酶和中性内肽酶的双重抑制剂 ,而且是氨肽酶、中性内肽酶和血管紧张素转化酶的三重抑制剂。结论 :四味镇痛中药具有不同的镇痛机制 ,其中 ,钩藤和羌活通过抑制氨肽酶和中性内肽酶而发挥镇痛作用     

Antioxidant properties of essential oils from lemon,grapefruit, coriander,clove, and their mixtures

Antioxidant properties of individual essential oils from lemon (Citrus limon L.), pink grapefruit (Citrus paradisi L.), coriander (Coriandrum sativum L.), and clove (Caryophyllus aromaticus L.) buds and their mixtures were studied by capillary gas-liquid chromatography. Antioxidant activity was assessed by oxidation of the aliphatic aldehyde hexanal to the carboxylic acid. The lowest and highest antioxidant activities were exhibited by grapefruit and clove bud essential oils, respectively. Mixtures containing clove bud essential oil also strongly inhibited oxidation of hexanal. Changes in the composition of essential oils and their mixtures in the course of long-term storage in the light were studied. The stability of components of lemon and coriander essential oils in mixtures increased compared to individual essential oils.     

银杏叶单组分双黄酮分离制备及抗氧化活性研究

从银杏叶中分离制备高纯度双黄酮对照品,探讨其抗氧化活性强弱。以60%乙醇-水提取的银杏叶浸膏为原料,反溶剂沉淀得到含量80.40%的双黄酮粗品,再以甲醇-水为流动相,半制备色谱梯度洗脱。结果得到了4种符合中药化学对照品要求的高纯度双黄酮,在最佳制备条件下,4种双黄酮纯度:阿曼托黄素(98.45%)、白果素(98.66%)、银杏黄素异构体(98.87%)、金松双黄酮(99.29%),其产率(mg/kg)分别为:22.5、23.8、192.5、71.8,考察了它们的抗氧化活性,并采用60%乙腈和有机酸水溶液对银杏黄素异构体进行了完全分离。建立的制备方法快速简便,所得单组分双黄酮纯度、产量高。本工作为单组分银杏双黄酮新药的研究与开发提供重要的技术支持。     

Antioxidant and Antibacterial Activities of Crude Extracts and Essential Oils of Syzygium cumini Leaves

This research highlights the chemical composition, antioxidant and antibacterial activities of essential oils and various crude extracts (using methanol and methylene chloride) from Syzygium cumini leaves. Essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS).The abundant constituents of the oils were: α-pinene (32.32%), β-pinene (12.44%), trans-caryophyllene (11.19%), 1, 3, 6-octatriene (8.41%), delta-3-carene (5.55%), α-caryophyllene (4.36%), and α-limonene (3.42%).The antioxidant activities of all extracts were examined using two complementary methods, namely diphenylpicrylhydrazyl (DPPH) and ferric reducing power (FRAP). In both methods, the methanol extract exhibited a higher activity than methylene chloride and essential oil extracts. A higher content of both total phenolics and flavonoids were found in the methanolic extract compared with other extracts. Furthermore, the methanol extract had higher antibacterial activity compared to methylene chloride and the essential oil extracts. Due to their antioxidant and antibacterial properties, the leaf extracts from S. cumini may be used as natural preservative ingredients in food and/or pharmaceutical industries.     

Phytochemical,Ecological and Antioxidant Evaluation of Wild Sicilian Thyme: Thymbra capitata (L.) Cav.

In a broad survey conducted throughout the Sicily region, 45 different sites were identified where thyme grows wild. All the biotypes collected were classified as Thymbra capitata (L.) Cav. (syn. Thymus capitatus (L.) Hoffmanns . & Link ). Cluster analysis based on the main morphological characteristics of the plant led to the division of the biotypes into 3 major groups. All samples were analyzed for their secondary phytochemical metabolites identified in the extracts and the essential oils. LC‐UV‐DAD/ESI‐MS and GC‐FID/GC‐MS have been applied to characterize the extracts and the essential oils, respectively. In the extracts, 15 flavonoid derivatives with taxifolin‐di‐O‐glucoside and thymusin as main components, and 2 organic acids, with a large predominance of rosmarinic acid, were identified. On the whole 37 compounds were fully characterized in the essential oils, carvacrol was identified as the main component with an average value of 73.93%. The total phenol content and the antioxidant activity of all phytochemical complexes were determined with the Folin–Ciocalteu (FC) assay, the UV radiation‐induced peroxidation in liposomal membranes (UV‐IP test), and the scavenging activity of superoxide radical ().     

Metal ion and antioxidant alterations in leaves between different sexes of Ginkgo biloba L

A comparative study was carried out to determine some valuable phytochemical components, macro- and microelement and redox parameters in leaves of male and female Ginkgo biloba trees and in extracts made from them. G. biloba extracts have become more popular as a therapeutic agent in the modern pharmacology in neurodegenerative diseases, in which increased brain metal levels can be observed and free radical reactions are involved. Macro- and microelement components, total phenol content, H-donating activity and reducing power as well as total scavenger capacity were determined in the samples. Well detectable differences were obtained for micro- and macroelement contents between male and female samples, but no toxic elements could be detected in the extracts. Male extracts contained more hazardous metals (e.g. Fe) compared to the female ones, while extracts from female leaves had higher levels of ions, which are known to have beneficial effects in neurodegenerative diseases. The ethanolic extracts of male leaves showed the highest H-donating activity, reducing power and total phenol content, as well as the best total scavenger activity. Ginkgo extracts due to the antioxidant properties may have favourable effects as dietary supplements in several neurodegenerative diseases, but this study draws the attention that critical evaluation is required in view of the potential hazard induced by their metal ion constitution. Our results lead us to the conclusion that although the aqueous extracts of female leaves are characterized by relatively lower antioxidant properties, they may be more eligible for these purposes due to their favourable metal ion constitution.     

银杏叶愈伤组织和叶中超氧化物歧化酶、总黄酮类抗氧化活性剂活性的比较分析

以银杏（Ginkgo biloba L.）叶片为外植体进行愈伤组织的诱导和培养,筛选到适合银杏叶片愈伤组织诱导和继代的培养基。以此愈伤组织为研究材料,比较了叶片愈伤组织和叶片中两种活性成分超氧化物歧化酶（SOD）、黄酮的活性差异。结果表明,银杏叶片愈伤组织中SOD的活性明显比叶片中的SOD活性高,同时愈伤组织中SOD同工酶谱带也比叶中有更多表达,但愈伤组织中总黄酮含量却比叶片中的含量低。实验证实SOD和黄酮类物质具有清除超氧阴离子的作用,表明银杏叶片愈伤组织和叶片中具有不同的占主导作用的抗氧化活性的机制。