薄层色谱 - 生物自显影技术测定绵茵陈提取液中绿原酸的含量并评价其抗氧化活性

 目的 建立绵茵陈中绿原酸的含量测定方法并采用薄层色谱 - 生物自显影法研究绵茵陈提取液的抗氧化活性。 方法 薄层 扫描法测定绵茵陈提取液中绿原酸的含量,随后用 二苯代苦味肼基自由基 溶液显色,双波长扫描,获得其抗氧化成分的峰面积。 结果 常规薄层扫描与生物自显影扫描测定得到的 绿原酸 含量具有一致性, 由 生物自显影扫描法测得 色谱峰 总积分值明显大于绿原酸单峰面积,表明 绵茵陈中除了绿原酸外,还存在其它抗氧化能力较强的活性成分。 结论 以 DPPH 作显色剂,双波长扫描,可利用 TLC- 生物自显影技术对天然提取物中具有自由基清除及抗氧化活性的活性成分进行快速筛选与评价 。     

TLC-生物自显影法导向分离菝葜中抗氧化活性成分

目的:采用薄层色谱-生物自显影法导向分离菝葜中的抗氧化活性成分,为建立谱-效相关质控标准奠定基础。方法:用1,1-二苯基-2-苦肼基自由基乙醇溶液(DPPH)和传统显色剂显色,检识主要抗氧化活性成分,选择性进行导向分离鉴定。结果:经反复柱层析,从菝葜的丙酮提取物中分离鉴定了白黎芦醇(Ⅰ)、落新妇苷(Ⅱ)、黄杞苷(Ⅲ)和Helicioside A(Ⅳ)4个主要抗氧化活性成分。结论:该方法用于菝葜主要抗氧化活性成分的导向分离具有操作简便的优点,分离得到1个二苯乙烯化合物(Ⅰ)和3个二氢黄酮醇苷类化合物(Ⅱ、Ⅲ、Ⅳ),其中化合物(Ⅳ)为首次从该属植物中获得。     

藏药三果汤散抗氧化有效成分的薄层色谱-生物自显影及HPLC指纹图谱

目的:初步建立藏药三果汤教的HPLC指纹图谱,研究藏药三果汤散的抗氧化活性,初步筛选出三果汤散中抗氧化有效成分.方法:采用薄层色谱-生物自显影技术和1,1-二苯基-2-三硝基苯肼(DPPH)分光光度法对不同来源的三果汤散、单味药对照药材及其中单体成分没食子酸、没食子酸乙酯、鞣花酸、柯里拉京进行抗氧化作用初步测定,并采用高效液相色谱法初步建立了三果汤散的指纹图谱.结果:不同来源的三果汤散的抗氧化作用差异不大,所含化学成分以没食子酸抗氧化作用最强,揭示没食子酸可能是三果汤散抗氧化的主要有效成分之一.结论:该方法准确、简便可行,为进一步探索三果汤散抗氧化有效成分提供了科学依据.     

TLC-生物自显影法筛选榆叶合叶子的抗氧化活性

目的：建立榆叶合叶子中黄酮类成分的TLC鉴别方法和运用TLC-生物自显影鉴别方法,初步筛选榆叶合叶子中的抗氧化活性成分.方法：以绣线菊苷、金丝桃苷、芦丁、槲皮素为对照品,采用三种薄层展开系统,选出最佳薄层展开系统;喷以0.1%的DPPH无水乙醇溶液显色,筛选抗氧化活性.结果：榆叶合叶子黄酮类物质的TLC鉴别的最佳展开系统为乙酸乙酯-甲酸-水（8：1：1）;TLC-生物自显影抗氧化活性筛选中,黄酮类成分的薄层板呈紫色背景黄色斑点.结论：榆叶合叶子药材中黄酮类成分的TLC鉴别方法可行,重复性好,可作为榆叶合叶子药材的薄层鉴别方法;榆叶合叶子药材中的黄酮类成分具有抗氧化活性.     

地方习用2种洋甘菊的数码显微鉴别研究

目的:建立区分新疆习用2种洋甘菊(母菊、罗马洋甘菊)的数码显微鉴别方法。方法:采用水合氯醛和粉末透化法,数码显微镜观察研究2种洋甘菊花粉末的主要显微特征。结果:2种洋甘菊均具有草酸钙小簇晶、腺毛、导管等显微结构,但其非腺毛、花粉粒具有明显差异,罗马洋甘菊中具有非腺毛、3个萌发孔,而母菊中无非腺毛、具有4个萌发孔。结论:2种洋甘菊显微特征中花粉粒萌发孔的数目差异及有无非腺毛可作为新的鉴别方法区分2种洋甘菊,为其药材质量标准制定以及进一步深入研究和开发利用提供科学依据。     

TLC生物自显影技术在药物筛选中的应用

TLC生物自显影是一种将薄层色谱分离和生物活性测定相结合的药物筛选方法,具有操作简单、耗费低、灵敏度和专属性高等优点,是一种快速测定生物活性的方法。可用于对具有抗菌/真菌,抑制胆碱酯酶以及清除自由基和抗氧化等活性的天然产物的筛选,可实现活性指导的提取分离。利用TLC生物自显影,可测定单体活性化合物的最小抑制浓度(MID),通过与对照品的MID值比较,能够推测该化合物活性的强弱。此外,利用TLC生物自显影定性及定量的特征,还可对食物、水样及动物组织中抗生素残留量进行监测。现综述TLC生物自显影技术及其在天然产物筛选中的应用,同时对其优点及不足也进行了总结。     

一种 TLC 生物自显影方法检测中药中单胺氧化酶抑制剂

目的：建立一种 TLC 生物自显影方法检测中药中单胺氧化酶抑制剂。方法：中药提取物以适当展开体系于硅胶板展开,然后以雾状均匀喷洒酶溶液,37℃预反应20min,之后以雾状喷洒显色剂与底物混合溶液。对于一个最优的底物选择,通过用 HPLC 来评价筛选一系列潜在底物化合物。结果：单胺氧化酶抑制剂在蓝色背景薄层板上会出现一个白色斑点,以磷酸异丙烟肼作为阳性药,检测限为0．01μg。中药路路通（Liquidambar formosana）乙醇提取物在硅胶板上展开显示出了单胺氧化酶抑制活性斑点。筛选出的最优底物为酪胺。结论：建立了一个新的 TLC 生物自显影方法,其可以快速筛选出中药中的单胺氧化酶抑制剂并为活性跟踪分离提供有力支持。     

DPPH法研究新疆阿魏的抗氧化活性

目的:采用紫外-DPPH法测定新疆阿魏的总抗氧化活性,并结合薄层生物自显影法(Bio-TLC-DPPH)鉴别其抗氧化活性成分。方法:以紫外-可见分光光度法测定DPPH溶液及10批新疆阿魏供试品溶液与DPPH溶液反应后的吸光度,计算清除率及EC50;依据2010版《中国药典》及文献中阿魏的提取方法,探索合适展开系统,喷以DPPH溶液显色后检视新疆阿魏抗氧化活性成分。结果:新疆阿魏甲醇提取液对DPPH自由基的EC50为5mg/mL;乙酸乙酯提取液以正己烷-石油醚(19:1)展开得到新疆阿魏特征抗氧化活性成分。结论:采用DPPH法可对新疆阿魏抗氧化活性物质进行鉴别。     

洋甘菊提取物对2型糖尿病小鼠血糖的影响及其抗氧化作用研究

目的：探讨洋甘菊醇提物对链脲佐菌素(STZ)诱导2型糖尿病模型小鼠血糖的影响,测定洋甘菊各提取物对正常小鼠抗氧化及其体外抗氧化能力。方法：洋甘菊经乙醇回流提取得其醇提物(CT);洋甘菊经水煎提取得其水提物(ST);洋甘菊醇提物经大孔树脂纯化后得洋甘菊总黄酮(HT)。采用高糖高脂饲料联合STZ法建立2型糖尿病小鼠模型,灌胃给予高、中、低剂量醇提物,两周后检测小鼠给药前后血糖值变化和葡萄糖耐量。采用正常小鼠进行抗氧化实验,分别灌胃给予高、中、低剂量的ST、CT、HT,21d后检测小鼠血清中的超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-PX)。测定洋甘菊醇提物对各类自由基清除率,评价洋甘菊醇提物的体外抗氧化能力。结果：2型糖尿病模型小鼠经CT干预两周后,与模型对照组比较,盐酸二甲双胍及CT高、中剂量组空腹血糖值均显著降低(P＜0.01,P＜0.05);糖耐量实验中,与模型对照组比较,盐酸二甲双胍组、CT高中剂量组在各时间点均可显著性降低糖尿病小鼠血糖值(P＜0.01,P＜0.05);在抗氧化实验中,与正常组比较,CT及HT各剂量组均可使小鼠血清中SOD、GSH-PX显著升高,MDA含量显著降低(P＜0.01,P＜0.05);在体外抗氧化实验中,洋甘菊醇提物在浓度为1.0mg/mL时,显示对DPPH·和O-₂·有一定的清除能力,对·OH清除作用不明显。结论：洋甘菊提取物具有较好的降血糖作用和抗氧化作用。     

云南普洱茶抗氧化活性的比较研究

目的:比较云南5个产地普洱茶的抗氧化活性.方法:选择3年发酵的普洱饼茶,采用DPPH测定其抗氧化活性和自由基消除活性.结果:5个产地的普洱茶提取物均具有一定的抗氧化活性,以云南大理下关产普洱茶的抗氧化能力最强,其EC<,50>值为8.88 mg·L<'-1>,云南思茅最弱,其EC<,50>值为21.81 mg·L<'-1>,云南5个产地普洱茶抗氧化活性的强弱顺序依次为:大理下关普洱茶>西双版纳普洱茶>临沧普洱茶>红河普洱茶>思茅普洱茶.结论:普洱茶是一种优良的天然抗氧化剂和自由基消除剂,云南不同产地普洱茶的抗氧化活性略有差异.     

银杏叶黄酮类成分体外及经肠吸收后抗氧化活性比较

[目的]比较银杏叶提取物中三个主要的银杏黄酮苷元体外及经肠吸收后抗氧化活性。[方法]采用1,1-二苯基-2-三硝基苯肼(DPPH)法(1,1-二苯基-2-三硝基苯肼法)测定模型药物体外及肠吸收液对自由基的清除作用,测定药物的抗氧化活性。[结果]槲皮素、异鼠李素、山奈酚体外清除DPPH自由基的EC50分别为78.6μm,203.2μm,222.0μm;药物肠吸收液DPPH清除率趋势为:槲皮素异鼠李素山奈酚,其清除率较体外相比有所降低;3个单体不同配比的肠吸收液DPPH清除率显示以提取物中所含比例混合清除率数据高于其他两组。[结论]3个单体体外及肠吸收液均能够清除DPPH自由基,且清除能力为:槲皮素异鼠李素山奈酚;肠吸收后药物清除率下降,可能与单体在肠道中产生分解有关,其原因还需进一步探讨,3个单体以提取物所含比例混合后抗氧化活性要好。     

Comparison of antioxidant activity and phenolic content of three lichen species

The antioxidant activities (AA), reducing powers (RP) and total phenolic contents (TPC) of methanol and water extracts of three lichen species, Usnea longissima Ach., Usnea florida (L.) Weber ex Wigg. and Lobaria pulmonaria (L.) Hoffm. were determined in vitro. Of the extracts tested, the methanol extracts of Lobaria pulmonaria and Usnea longissima showed potent antioxidant activities. The methanol extract of L. pulmonaria also had the highest total phenolic contents (87.9 mg/g lyophylisate). For the methanol extract of this species, there was also a strong correlation between antioxidant activity and total phenolic contents. However, a similar correlation was not observed for U. longissima. Although the methanol extract of U. longissima had a lower phenolic content (38.6 mg/g lyophylisate), it exhibited potent antioxidant activity. On the other hand, there was a strong correlation between the reducing powers and the total phenolic contents of the extracts. The highest reducing power was determined for the methanol extract of L. pulmonaria.     

Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method

Brazilian plant extracts belonging to 16 species of 5 different families (71 extracts) were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free-radical. The ability to scavenge DPPH radical was measured in these experiments by the discoloration of the solution. Ginkgo biloba and rutin, commonly used as antioxidants for medical purposes, were used as standards. Based on our results, we can say that as a general rule the ethanol extracts of plants belonging to the Verbenaceae family showed lower EC(50) values than the other plant extracts. Among the partitions, the more polar ones (ethyl acetate and n-butanol) are those that generally have higher antioxidant activity (AA).     

化学发光法测定白果白蛋白的体外抗氧化活性

目的研究白果白蛋白的体外抗氧化活性、对DNA损伤的保护作用及其作用机制。方法以莲房原花青素和小牛血清蛋白为对照,分别采用邻苯三酚-鲁米诺化学发光体系测定了白果白蛋白对超氧阴离子的清除作用,硫酸铜-邻菲啉-抗坏血酸-双氧水、硫酸亚铁-鲁米诺-双氧水和硫酸亚铁-鲁米诺3个体系测定了白果白蛋白对羟自由基的清除作用,双氧水-鲁米诺体系测定了白果白蛋白对体外双氧水的清除作用,采用硫酸铜-邻菲啉-抗坏血酸-双氧水-脱氧核糖核酸体系测定了白果白蛋白对体外DNA损伤的保护作用。结果白果白蛋白具有较好的体外清除活性氧和保护DNA损伤的活性,但在硫酸亚铁-鲁米诺-双氧水和双氧水-鲁米诺化学发光体系中表现出"促氧化"作用。结论采用化学发光体系衡量白果白蛋白的抗氧化活性具有选择性。     

Correlation between the in vitro antioxidant activity and polyphenol content of aqueous extracts from Bulgarian herbs

The water phase antioxidant activity of extracts from 23 Bulgarian medicinal plants was studied in relation to their polyphenol content in comparison with mate, black tea, honeybush and rooibos foreign species. Antioxidant activity was measured by the ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) cation radical decolorization assay, and the total polyphenol content was assayed according to the Folin-Ciocalteu method. Five Bulgarian plant extracts exhibited higher antioxidant activity than that of mate, which is 21.7% of all Bulgarian herbs included in this study. These were Alchemilla vulgaris L. (4.79 +/- 0.14 mm), Sambucus ebulus L. (4.03 +/- 0.07 mm), Mentha spicata L. (3.90 +/- 0.03 mm), Fragaria vesca L. (3.74 +/- 0.06 mm), Crataegus monogyna Jacq. (3.63 +/- 0.05 mm). Another eight Bulgarian medicinal plant extracts exhibited an intermediate antioxidant activity - lower than that of mate and higher than that of honeybush, which makes 34.8% of all Bulgarian herbs included in the study. More than half of the herbal extracts included in the present study exhibited antioxidant activity higher than or comparable to the reference foreign plants. A positive correlation (r = 0.92) between antioxidant activity and polyphenol content was found, suggesting that the antioxidant capacity of the aqueous plant extracts is due to a great extent to their polyphenols.     

黄素馨化学成分及其抗氧化活性

对黄素馨Jasminum giraldii根皮的化学成分进行研究。采用正相硅胶、Sephadex LH-20以及Rp-HPLC制备柱色谱法,从黄素馨乙醇提取物的乙酸乙酯萃取部位中分离得到10个化合物,通过MS和NMR等谱学方法,鉴定结构为（+）-梣皮树脂醇（1）,（+）-丁香树脂醇（2）,（+）-丁香脂素-4’-O-β-D-葡萄糖苷（3）,齐墩果酸（4）,3-甲氧基-4-羟基桂皮醛（5）,芥子醛（6）,3,5-二甲氧基对羟基苯甲醛（7）,1-（4-甲氧基苯基）乙醇（8）,反式桂皮酸（9）,4-（1-甲氧基乙基）苯酚（10）。化合物1~3,5~8以及10为首次从素馨属植物中分离得到;化合物4和9为首次从该植物中分离得到。采用 DPPH自由基清除法对分离得到的化合物进行抗氧化活性的筛选。结果显示,化合物1显示出强的自由清除能力（IC₅₀为55.1 μmol·L^-1）,活性强于维生素C（IC₅₀为59.9 μmol·L^-1）,化合物2显示中等强度自由清除能力（IC₅₀为79.0 μmol·L^-1）,活性弱于维生素C,但强于2,6-二羟丁基对甲酚（IC₅₀为236 μmol·L^-1）。     

Antioxidant activity of puha (Sonchus oleraceus L.) as assessed by the cellular antioxidant activity (CAA) assay

There is considerable interest in antioxidant dietary components that can be protective against degenerative diseases in humans. Puha (Sonchus oleraceus L.) is a rich source of polyphenols, and exhibits strong antioxidant activity as measured by the 2,2‐diphenylpicrylhydrazyl (DPPH) assay. However, the potential of puha to protect against degenerative diseases requires that low molecular weight antioxidants (LMWA) are absorbed by, and active in, human cells. The cellular antioxidant activity (CAA) assay was used to investigate the antioxidant activity of puha leaf extracts. Preparation methods of freezing and freeze‐drying reduced the total polyphenolic content compared with fresh puha, but did not affect the LMWA potential as determined by the DPPH assay. The IC₅₀ values were 0.012 ± 0.003 mg/mL and 0.010 ± 0.005 mg/mL for freeze‐dried and fresh puha leaves, respectively. Using the CAA assay, it was shown that LMWAs from foliar extracts of puha were effectively absorbed into HepG2 cells, and exerted antioxidant activity at levels comparable to those of extracts from blueberry fruits, the much‐touted antioxidant superfood. Methylene blue staining of HepG2 cells indicated that puha extracts were not cytotoxic at concentrations below 100 mg DW/mL. The data indicate the potential of puha as a nutraceutical supplement for human health. Copyright © 2011 John Wiley & Sons, Ltd.     

Screening of some Greek aromatic plants for antioxidant activity

The role of antioxidants in preventing oxygen radical and hydrogen peroxide induced cytotoxicity and tissue damage in various human diseases is increasingly recognized. In this study the in vitro antioxidant activity of the ethanol extracts obtained from 21 aromatic plants belonging to the Lamiaceae family was investigated. Of the extracts tested, those of Salvia ringens, Salvia pomifera, Stachys spruneri, Origanum dictamnus, Phlomis lanata, Ballota pseudodictamnus, Ballota acetabulosa, Teucrium polium, Calamintha glandulosa and Micromeria graeca exhibited the same activity as alpha-tocopherol.