三叉耳蕨挥发油HS-SPME-GC-MS分析

采用顶空固相微萃取和气质联用技术(HS-SPME-GC-MS),从根中鉴定了31个成分,从叶中鉴定了22个成分。其中有16个共有成分。三叉耳蕨根的挥发油的主要成分是十六醛(11.24%)、正十六酸(9.07%)、十六烷(6.31%)和2,6,10,14-四甲基-十五烷(6.05%)。叶的挥发油的主要成分是邻苯二甲酸二乙酯(9.85%)、(E)-4-(2,6,6-三甲基-2-环己-1-烯基)-3-丁烯-2-酮(9.32%)、6,10,14-三甲基-2-十五烷酮(8.25%)和(E)-4-(2,6,6-三甲基-1-环己-1-烯基)-3-丁烯-2-酮(8.05%)。     

黄树莓叶片中黄酮类物质的提取及抗氧化性

黄酮类物质具有降血糖、降血脂、抗心律失常、抗氧化高效性与低毒性、抗衰老等生理活性1 2 。从药食两种植物中筛选出高效低毒且经济的抗氧化性强的物质 ,必将是近一步开发天然高效食品抗氧化剂的重要途径[3 5] 。黄树莓是我国北方地区小浆果树种之一 ,其中以黑龙江分布较多。黄树莓的浆果甜而芳香 ,营养丰富 ,是鲜美的生食果品 ,也可加工制成果酱、果酒、果汁和蜜饯等。它又是密源植物和药用植物 ,有止渴、痰、发汗、活血的效用。本实验以测定黄树莓叶片总黄酮含量并考察了提取物粗黄酮对猪油的抗氧化性。1　实验部分1 1　主要试剂及仪…     

二氢槲皮素的提取及抗氧化性研究

采用浸提法,分别用水、丙酮-水作为提取溶剂从落叶松中提取二氢槲皮素,通过L9(34)正交实验优化最佳提取条件;研究不同油脂中二氢槲皮素的抗氧化效果;比较Vc、BHT、EDTA、柠檬酸对二氢槲皮素的抗氧化协同作用.结果表明,以水作为溶剂的最佳提取条件为:提取温度90 ℃、料液比1:12(g/mL)、提取时间120 min...     

柠檬汁总黄酮的提取纯化工艺研究

利用超声波辅助提取柠檬汁中总黄酮,分光光度法测定总黄酮类化合物含量,利用单因素实验,找出了最佳提取工艺条件70%乙醇、料液比1∶1.5、超声温度55℃、超声时间60 min。通过对比实验找出了最佳纯化方法二氯甲烷在1∶1.5比例下萃取、大孔树脂吸附18 h、70%乙醇洗脱,洗脱液除醇后所得的黄酮浓度最高达1.851 mg/m L。     

牛大力总黄酮提取工艺及不同萃取物的抗氧化活性研究

为了考察牛大力乙醇提取物中总黄酮的含量及抗氧化活性。通过L16(45)正交实验,超声波辅助提取牛大力中总黄酮,得到最佳工艺,再测试乙醇提取物和四个萃取物对羟基自由基(.OH)和DPPH自由基(DP-PH.)的清除效果。最佳工艺为:φ(EtOH)=75%、m(牛大力,g)∶V(EtOH,mL)=1∶25、温度60℃、时间60min,该条件下,牛大力总黄酮得率可达2.14mg.g-1。其中,牛大力乙醇提取物中氯仿萃取物中黄酮含量最高,为5.52mg.g-1;而且氯仿萃取物对DPPH.的清除效果最好,其半数抑制浓度(IC50)为40.97μg.mL-1;乙酸乙酯萃取物对羟基自由基的清除效果最好,其IC50值为90.5μg.mL-1。牛大力乙醇提取物中石油醚、氯仿、乙酸乙酯萃取物都有很好的抗氧化活性,且稳定性、重复性好。     

超声波辅助提取茶叶总黄酮及抗氧化活性分析

采用超声波辅助法探讨了铁观音茶叶中总黄酮的最佳提取工艺条件,并测定了铁观音茶叶总黄酮清除羟基自由基的能力.结果表明,超声波功率400 W,料液比1∶30 g·mL~(-1),浸提时间30 min,乙醇浓度50%为超声波辅助提取铁观音茶叶总黄酮的最佳工艺条件,总黄酮提取率为4.74%;抗氧化实验表明随着铁观音茶叶总黄酮浓度的增大,其对羟基自由基的清除能力增大,当浓度达到0.80 g/L,清除率为65.14%,与BHT相比具有较强的抗氧化能力.     

超声波法提取紫甘薯叶总黄酮的工艺研究

采用超声波提取法,以总黄酮含量为考察指标,利用单因素试验法对影响总黄酮提取率的因素进行了分析,然后通过正交试验确定紫甘薯叶总黄酮的最佳工艺条件。研究表明,影响紫甘薯叶总黄酮提取率的主次因素为:溶剂pH值溶剂的浓度料液比提取时间。紫甘薯叶总黄酮的最佳提取工艺为:乙醇体积分数80%,料液比1∶40(W/V),提取时间30 min,提取溶剂pH 9。在此条件下甘薯叶中总黄酮提取率为8.22%。     

微波法提取水蓼中总黄酮的工艺研究

研究了水蓼中总黄酮的微波提取最佳工艺。采用单因素试验和正交试验考察微波功率、乙醇浓度、微波辐射时间、料液比对水蓼中总黄酮提取率的影响,优选提取工艺。最佳工艺条件为:微波功率为520W,乙醇浓度为60%,微波辐射60s,间歇辐射3次,料液比为1g∶20mL。结果表明,微波提取具有提取率高、提取速度快等特点,用于中草药的提取应用前景广阔。     

庐山石韦中总黄酮的提取工艺研究

优选庐山石韦中总黄酮类化合物的提取工艺.以芦丁为对照品,就微波提取法、碱提酸析法、丙酮提取法、乙醇提取法对庐山石韦中总黄酮类化合物的提取效果进行了比较,并采用正交试验,以提取物中总黄酮得率为指标进行试验.优选出庐山石韦中总黄酮类化合物的最佳提取工艺为20倍量的55%乙醇溶液在80℃条件下浸提5 h.总黄酮的得率为5.91%.该提取工艺可行.提取率高.     

火棘果总黄酮的提取和纯化研究

采用溶剂提取法、索氏提取法、循环超声提取法提取火棘果总黄酮,利用静态吸附方法筛选分离火棘果总黄酮的最适大孔树脂,利用动态吸附方法研究最适大孔树脂纯化火棘果总黄酮的条件,并用紫外分光光度法测定其含量。得出结果为循环超声提取时间短、效率高;D101大孔吸附树脂纯化效果最好,最佳工艺为上样浓度为0.899 8g·L-1,上样液pH为4,上样体积5BV,上样速率2.5mL·min-1,用5BV70%乙醇以2.0 mL·min-1速率洗脱,经树脂纯化后总黄酮的纯度由原来的9.00%提高至28.11%。     

Extraction technology,component analysis,and in vitro antioxidant and antibacterial activities of total flavonoids and fatty acids from Tribulus terrestris L. fruits

The current study focused on the extraction technology, components analysis, in vitro antioxidant and antibacterial activities of total flavonoids and fatty acids from Tribulus terrestris L. fruits. The extraction process of total flavonoids and fatty acids was optimized by the response surface method, and the compositions were identified from the two extracts by HPLC–DAD–ESI–MS^? and GC–MS, respectively. In addition, the antioxidant and antibacterial activities were evaluated by assay of ABTS, DPPH radical scavenging activity, ferric reducing antioxidant power and minimal inhibitory concentration. The yields of total flavonoids and fatty acids were 0.46 and 9.76% under the optimized conditions. Moreover, nine and eight compositions were identified from the two extracts based on the related references, respectively. In addition, total flavonoids and fatty acids extracts both exhibited certain antioxidant and antibacterial activities. The present findings suggest that total flavonoids extracted from T. terrestris L. fruits comprised a more interesting candidate than fatty acids for the research and development of natural and healthy antioxidants and antibacterial agents for the pharmaceutical and food industries.     

Isolation of a new flavanone from Daidai fruit and hypolipidemic activity of total flavonoids extracts

In order to further discover the medicinal value of Daidai fruit, an exploration on the hypolipidemic activity of total flavonoids extracts of Daidai fruit (TFEODF) was conducted in high-fat diet-induced hyperlipemia rats. Results indicated that TFEODF exhibited significant hypolipidemic activity which resulted in the decline of serum total cholesterol, triglyceride, low density lipoprotein cholesterol, arteriosclerosis index and rise of high density lipoprotein cholesterol in hyperlipemia rats. For the purpose of expounding the chemical constituents of TFEODF, a phytochemical investigation of TFEODF was carried out for the first time. Research resulted in the isolation of a new compound together with 17 known compounds. This study lay a foundation for the development of a new hypolipidemic agent of traditional Chinese medicine whose chemical constituents were clarified.     

Identification of flavonoids and chlorogenic acids in elm fruits from the genus Ulmus and their antioxidant activity

Elm fruits were once an important food source in the years of famine. Research on the functional compounds in elm fruits was almost unavailable. In this study, we established an efficient high‐performance liquid chromatography method for the simultaneous separation of eight chlorogenic acids and 28 flavonoids in elm fruits for the first time. Total flavonoid contents ranged from 286 mg/100 g (Ulmus laciniata) to 1228 mg/100 g (U. pumila). High concentrations of rutin, quercetin 3‐O‐glucoside, and kaempferol derivatives were present in U. laevis, U. castaneifolia, and U. pumila, respectively. Furthermore, the fruit extracts of U. americana, U. castaneifolia, U. davidiana, and U. pumila showed higher antioxidant activity. These results suggest that fruits of these species can be used as bioresources for the extraction of the corresponding functional compounds. This work provides informative data and can be an important reference for future research on elm fruits as a renewed food resource.     

贯叶金丝桃提取物中总黄酮的测定方法

以中药材 贯叶金丝桃的提取物为对象 ,对其主要有效成分黄酮类化合物总含量测定的几种分光光度法进行了比较研究。发现文献中某些常用的分光光度法存在严重的缺陷。通过与高效液相色谱法测定结果比较 ,建立了一种测定总黄酮含量的分光光度法     

Phytochemical screening,total phenolic content and antioxidant activity of Byrsonima species

The species of the Byrsonima genus (Malpighiaceae) have been used in folk medicine to treat gastrointestinal disorders, asthma and skin infections. In this study, the total phenolic content, antioxidant activity and phytochemical screening were carried out in polar extracts of Byrsonima coccolobifolia, Byrsonima verbascifolia and Byrsonima intermedia. The presence of tannins and flavonoids in the samples and high phenols content was observed. B. coccolobifolia and B. intermedia species showed the best results of antioxidant action. It was analysed the correlation between the methods, and there was a great correlation between phenolic content and antioxidant assay, showing that the phenolic substances contribute to the antioxidant activities of these plants.     

黄酮体化合物抗肿瘤活性的量子化学研究

本文对黄酮类化合物抗肿瘤活性进行了量子化学研究。采用从头算方法计算了黄酮体化合物的电荷分布，并基于电荷分布提出了黄酮体化合物表现抗肿瘤活性时与受体作用的模型：A环与受体的负电荷中心结构，C环与受体的正电荷中心结合，其他部分通过氢键与受体发生作用，氢键在受体的作用中起到很大的作用。     

Optimization of Flavonoid Extraction from Xanthoceras sorbifolia Bunge Flowers,and the Antioxidant and Antibacterial Capacity of the Extract

In the present work, the extraction process of total flavonoids (TFs) from X. sorbifolia flowers by ultrasound-assisted extraction was optimized under the response surface methodology (RSM) on the basis of single-factor experiments. The optimal extraction conditions were as follows: ethanol concentration of 80%, solid–liquid ratio of 1:37 (g/mL), temperature of 84 °C, and extraction time of 1 h. Under the optimized conditions, the extraction yield of the TFs was 3.956 ± 0.04%. The radical scavenging capacities of TFs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were much greater than that of rutin. The results of antibacterial experiments indicated that the TFs displayed strong inhibitory activities on E. coli, S. aureus and Bacillus subtilis. Therefore, X. sorbifolia flowers can be used as a novel source of natural flavonoids, and the TFs have potential applications as natural antioxidants or antibacterial agents in the food and pharmaceutical industries.     

Cytotoxic flavonoids and other constituents from the stem bark of Ochna schweinfurthiana

Seven flavonoids, hemerocallone (1), 6,7-dimethoxy-3′,4′-dimethoxyisoflavone (2), amentoflavone (4), agathisflavone (6), cupressuflavone (8), robustaflavone (9) and epicatechin (10), together with three other compounds, lithospermoside (3), β-D-fructofuranosyl-α-D-glucopyranoside (5) and 3β-O-D-glucopyranosyl-β-stigmasterol (7), were isolated from the ethyl acetate extract of the stem bark of Ochna schweinfurthiana F. Hoffm. All the compounds were characterised by spectroscopic and mass spectrometric methods, and by comparison with literature data. Cytotoxicity of the extracts and compounds against cervical adenocarcinoma (HeLa) cells was evaluated by MTT assay. Compounds 4 and 6 exhibited good cytotoxic activity, with IC₅₀ values of 20.7 and 10.0 μM, respectively.     

绿茶及其饮料中总黄酮的分析

以绿茶及其饮料为分析对象采用三波长-光谱法测定绿茶及其饮料中黄酮的含量，有效地消除了吸收峰不对称给定量分析造成的影响，并校正了基于干扰组分(饮料中添加剂)的吸收光谱具有线性吸收产生的基线倾斜。本法的回收率为93％～106％，相对标准偏差小于0．48％。