Determination of total flavonoids content in buckwheat and inhibition of α-amylase activity

Diabetes is one of the most difficult chronic diseases to cure in the world,which seriously affects people’s health and quality of life.Flavonoids in buckwheat can regulate blood glucose levels by inhibitingα-amylase activity.Therefore,sweet buckwheat produced in Inner Mongolia was used as the research object,and buckwheat fl avonoids were extracted by ultrasonic-assisted extraction method.Total fl avonoids content was determined by ultraviolet-visible spectrophotometry.With acarbose as the positive control,the inhibition test ofα-amylase was carried out by DNS colorimetry to study the inhibition behavior of fl avonoids onα-amylase activity.The results showed that the extraction process of flavonoids was stable and reliable,and the established method for the determination of flavonoids was simple,accurate and reproducible.The total flavonoids content of buckwheat samples was 2.706 mg/g,buckwheat total fl avonoids extraction solution had an inhibitory eff ect onα-amylase,and its median inhibition concentration(IC_(50))was 38.53 mg/mL.The results of this experiment provide a technical reference for the development and utilization of fl avonoids in Inner Mongolia sweet buckwheat,and provide a theoretical reference for the development and application of flavonoid-rich hypoglycemic food.

Evaluation of Total Polyphenol and Flavonoid Contents of Fresh and Dried Pepper (Piper nigrum) from the Ivory Coast

The growing interest in the potential biological activity of polyphenols and flavonoids has highlighted necessity to assess their content in fresh and dried pepper from Ivory Coast. The total polyphenol content was determined using the Folin-Ciocalteu test and the total flavonoid content was also measured spectrophotometrically using the aluminum chloride colorimetric test. The results obtained indicate the total polyphenol levels of fresh and dried peppers are higher in the samples collected in Danane (0.8 ± 0.05 mg GAE/100g) and in Azaguie (0.4 ± 0.08 mg GAE/100g). The lowest concentrations were obtained with fresh and dried pepper samples collected in N’douci (0.22 ± 0.02 mg GAE/100g) and in PK 103 (0.22 ± 0.02 mg GAE/100g). The highest content of total flavonoids was revealed in the locality of PK 103 (1.85 ± 0.62 mg EC/100g) followed by the locality of Maféré (1.37 ± 0.25 mg EC/100g) respectively for black pepper and green pepper. Then, the lowest flavonoid contents were obtained in the dried pepper of Lopou (0.57 ± 0.03 mg EC/100g) and the fresh pepper of PK 103 (0.47 ± 0.03 mg EC/100g). The results obtained highlight the importance of these black spices as promising sources of phenolic compounds and could be used in pharmaceutical treatments and in food.

Evaluation of extracts and essential oil from Callistemon viminalis leaves:Antibacterial and antioxidant activities,total phenolic and flavonoid contents

Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(C.viminalis)leaves.Methods:The essential oil of C.viminalis leaves obtained by hydrodistillation was analyzed by GC/MS.Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)actives.Results:Fourteen components were identified in the essential oil,representing 98.94%of the total oil.The major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.Conclusions:It can be suggested that C.viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis.The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C.viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.

Total phenolic, flavonoid content, and antioxidant activity of flour, noodles, and steamed bread made from different colored wheat grains by three milling methods

The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg gallic acid equivalents g-1), total flavonoid content(319.3 μg rutin equivalents g-1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content(236.2 μg rutin equivalents g-1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour(P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities(by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.

GC-MS analysis,determination of total phenolics,flavonoid content and free radical scavenging activities of various crude extracts of Moringa peregrina(Forssk.) Fiori leaves

Objective:To perform phytochemical screening,estimate total phenolics,flavonoids and to evaluate antioxidant potential of Moringa peregrina(M.peregrina) leaves.Methods:The dried powdered leaves of M.peregrina(150 g) were extracted exhaustively by Soxhlet with ethanol and then fractionated into hexane,chloroform,ethy alacetate and methanol.All the prepared extracts were also analyzed by gas chromatography-mass spectrometry to identify and characterize the chemical compounds present in the crude extracts.Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts.Hydrogen peroxide and 1,1 diphenyl-2-picrylhydrazyl were used to determine in vitro antioxidant activity.Results:Phytochemical analysis of ethanol extract showed presence of major classes of phytochemicals.Gas chromatography-mass spectrometry results revealed presence of 19 phytoconstituents in hexane extract,6 in ethyl acetate and 7 compounds in methanolic extract.Methanol extract was found to contain the highest phenolic content and flavonoids.In vitro antioxidant activities of all crude extracts were significant and comparable with the standard ascorbic acid.Conclusions:Results of this study show that the leaves of M.peregrina are the rich source of phenolic compounds that can play an important role in preventing the progression of many diseases.

Study of total phenol,flavonoids contents and phytochemical screening of various leaves crude extracts of locally grown Thymus vulgaris

Objective:To prepare various crude extracts using different polarities of solvent and to quantitatively evaluate their total phenol,flavonoids contents and phytochemical screening of Thymus vulgaris collected from Al Jabal Al Akhdar,Nizwa.Sultanate of Oman.Methods:The leave sample was extracted with methanol and evaporated.Then it was defatted with water and extracted with different polarities organic solvents with increasing polarities.The prepare hexane,chloroform,ethyl acetate,hutanol and methanol crude extracts were used for their evaluation of total phenol,flavonoids contents and phytochemical screening study.The established conventional metliods were used for quantitative determination of total phenol,flavonoids contents and phytochemical screening.Results:Phytochemical screening for various crude extracts were tested and shown positive result for flavonoids,saponins and steroids compounds.The result for total phenol content was the highest in hutanol and the lowest in methanol crude extract whereas the total flavonoids contents was the highest in methanol and the lowest hexane crude extract.Conclusions:The crude extracts from locally grown Thymus vulgaris showed high concentration of flavonoids and it could be used as antibiotics for different curable and uncurable diseases.

Extraction Process and Content Determination of Total Flavonoids in Ginkgo( Ginkgo biloba L. ) Leaves

[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavonoids in ginkgo leaves were studied,and the optimal extraction conditions for flavonoids were determined by orthogonal test; and with quercetin as reference substance,total flavonoid content in ginkgo leaves was determined by UV spectrophotometry.[Results]The optimal extraction process was 4 h of Soxhlet extraction with methanol; and the total flavonoid contents had a good linear relation in the range of 0. 006 5-0. 039 mg/ml( R^2= 0. 999 9),the average content was stabilized at 1. 135%,and the average recovery of the method was 102. 0%. [Conclusions]This study selected the optimal extraction process for total flavonoids in ginkgo leaves. The test method is simple with high accuracy and precision,and is suitable for the extraction and determination of total flavonoids in ginkgo leaves.

Fruiting increases total content of flavonoids and antiproliferative effects of Cereus jamacaru D.C. cladodes in sarcoma 180 cells in vitro

Objective: To evaluate the influence of fruiting phenological stage on total flavonoid content, antioxidant activity, and antiproliferative effects of Cereus jamacaru(C. jamacaru)(mandacaru) cladodes and fruit. Methods: Fruit and cladodes at vegetative and fruiting stage of C. jamacaru were collected. The fruit was dissected and bark, pulp, and seeds were separated. Vegetative and fruiting cladodes, together with bark, pulp, and seeds were used to obtain five hydroalcoholic extracts. The extracts were investigated for total flavonoid content, using AlCl3 colorimetric method, antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging capacity and Fe^(2+) ion chelating activity, and in vitro antiproliferative effects(sarcoma 180 cells) by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2 H-tetrazolium bromide assay. Results: The extract of C. jamacaru cladodes at the fruiting stage showed higher flavonoid content compared to the other extracts. Seed extracts showed the highest antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) assays, and the extract of cladodes at vegetative stage showed better antioxidant activity in Fe^(2+) ion chelating activity. The extract of fruiting cladodes promoted higher antiproliferative effects compared to the other extracts. Conclusions: These findings suggest that fruiting increases the content of flavonoids and antiproliferative effects of C. jamacaru cladodes. Data reinforce the potential use of C. jamacaru cladodes and fruits as natural antioxidants and potent anticancer agent.

Effects of four metal Ions on phenylalanine ammoni-alyase activities and flavonoids content of ginkgo biloba leaves

The enzyme activities of phenylalanine ammonia-lyase from six years old Ginkgo biloba leaves in the potted orchard were induced by four groups of metal ions respectively. The PAL activities and flavonoids content were measured by the UV-Vis spectrophotometer. Changes of the whole year were also studied. The results showed that four groups of metal ion treatments had significant effects on the PAL activities and flavonoids contents in Ginkgo leaves. The treatments with 0.1% and 0.3% FeSO4, 0.1%, 0.2% and 0.3% ZnSO4, 0.1%, 0.3% and 0.5% MnSO4, 0.1% and 0.4% CuSO4 not only enhanced flavonoids contents, but also extended the optimum harvest dates of ginkgo leaves. The optimum combination was 0.1% FeSO4, 0.2% ZnSO4, 0.3% MnSO4, and 0.4% CuSO4. It could improve flavonoids content up to 1.619 4%.

Optimization of Extraction Process and Content Determination of Total Flavonoids from Sanguisorbae Radix and Carbonized Sanguisorba Root by Orthogonal Experimental Design

[Objectives] To optimize the extraction process of total flavonoids from Sanguisorbae Radix and carbonized Sanguisorba root,compare quality of different batches of Sanguisorbae Radix,study the effects of processing on the content of flavonoids,and provide scientific basis for reasonable utilization of Sanguisorbae Radix. [Methods] Test samples were prepared by heating,refluxing,and extraction,the extraction process was optimized by orthogonal experiment design,color was developed by NaNO_2-Al( NO_3)3-NaOH,and total flavonoids were measured by UV method at the wavelength of 510 nm. [Results] The linear relationship of rutin was excellent in the concentration range of 0. 1248 mg/mL-0. 5712 mg/mL,R^2= 0. 9997; the average recovery was 99. 67% and the RSD was 0. 70%. The optimum extraction conditions were as follows: the volume fraction of ethanol was 50%,the extraction temperature was 90℃,the extraction time was 90 min,and the solid-to-liquid ratio was 1∶ 20( g/mL). [Conclusions] After optimization of the extraction process,the extraction rate of total flavonoids in samples of Sanguisorbae Radix was significantly increased; there was certain difference in the content of total flavonoids between different batches of Sanguisorbae Radix and processed products; the total flavonoids significantly declines in carbonized sanguisorba root,and the influence of processing on its curative effect was to be further studied.

Content Determination of Total Flavonoids in Tetracera asiatica from 10 Different Production Areas in Guangxi

[Objectives] To determine the content of total flavonoids in Tetracera asiatica from different production areas in Guangxi and provide a basis for improving the quality standards of crude drug. [Methods] Using 50% ethanol as extractor,NaNO_2-Al(NO_3)_3-NaOH as chromogenic system and rutin as the reference substance,the content of total flavonoids from the crude drug was determined. [Results] A method for determining the content of total flavonoids was established,the content of total flavonoids was 11.35-21.35 mg·g^(-1),and the average content was 17.64 mg·g^(-1). [Conclusions] The method had high repeatability and stability,and the method was simple,rapid and sensitive and suitable for quantitative analysis.

Extraction Technology of Total Flavonoids from Pueraria lobata (Willd.) Ohwi and Content Determination of Pueraria lobata (Willd.) Ohwi at Different Altitudes

[Objectives]To optimize the extraction technology of total flavonoids from Pueraria lobata( Willd.) Ohwi. [Methods]The ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in Pueraria lobata( Willd.) Ohwi. With the puerarin as index,the reflux extraction and single factor test were employed to investigate the effects of temperature,time,ethanol concentration and solid-liquid ratio on the content of total flavonoids in Pueraria lobata( Willd.) Ohwi,respectively. Under the optimal extraction technology,the content of total flavonoids in Pueraria lobata( Willd.) Ohwi at different altitudes was determined.[Results] The optimum extraction process was as follows: 70%ethanol; solid-liquid ratio of 1∶ 30; 1 h reflux extraction. Under these conditions,the extraction rate of flavonoids in Pueraria lobata( Willd.) Ohwi was 11. 48%,the total flavonoids content of different kudzu parts was in the order of roots > stems > leaves,and the total flavonoids content of the sample at about an altitude of 1000 m was significantly higher than at the altitudes of 1400 m and 1700 m.[Conclusions]It was suggested that the Pueraria lobata( Willd.) Ohwi should not be cultivated as medicinal plant in too high mountains,and the stems and leaves of Pueraria lobata( Willd.) Ohwi could be used as raw materials for extracting total flavonoids.

HPLC Method for Determination of Content of Total Flavonoids from Ginkgo (Ginkgo biloba L.) Leaves

[Objectives]This study was conducted to determine the content of total flavonoids in ginkgo ( Ginkgo biloba L.) leaves.[Methods]The content of total flavonoids from ginkgo leaves was determined by reversed phase-high performance liquid chromatography (RP-HPLC).The flavonoid glycosides were first extracted with methanol,and hydrolyzed with hydrochloric acid solution to prepare a test solution.Platisil ODS C18 column (150 mm×4.6 mm,5 μm) and the mobile phase V methanol ∶ V water (0.4% phosphoric acid solution)=85∶ 15 were selected for HPLC separation.The HPLC separation was performed with the column at a column temperature of 25℃ using the mobile phase at a flow rate of 1 ml/min.The sample size was 10 μl,and detection was performed with an Agilent HPLC ultraviolet detector at 360 nm.[Results]The reference substance,quercetin,had good linearity in the range of 0.002 6-0.052 0 g/L,with a correlation coefficient of 0.999 7;and the RSD was 1.26%.[Conclusions]The determination method has rapid and simple operation with accurate results and is good in repeatability.This method is suitable for the determination of content of total flavonoids in ginkgo leaves.

谷子籽粒类黄酮含量和粒色的QTL定位

谷子(Setaria italica L.)是我国北方地区重要的粮食作物,籽粒营养丰富,且富含多种类黄酮物质,对生长发育和品质形成发挥着重要作用。目前谷子籽粒类黄酮合成及粒色形成相关调控机制研究较少。分析谷子类黄酮含量及粒色性状相关的QTL,为类黄酮合成关键基因的精细定位、克隆及功能研究奠定基础,同时,也为揭示谷子类黄酮合成及代谢机制和培育富含类黄酮谷子品种提供技术支撑。本研究以红粒色高类黄酮品种金苗红酒谷和黄粒色低类黄酮品种豫谷28为亲本构建的包含150个家系的重组自交系(RIL)群体为试验材料,在谷子成熟期对籽粒粒色和类黄酮含量相关性状进行分析。同时,采用复合区间作图法(composite interval mapping,CIM)对粒色和类黄酮含量进行QTL定位与分析,并对QTL置信区间内的候选基因进行预测。相关性分析表明,类黄酮含量与粒色呈显著正相关。共定位到4个与类黄酮含量相关和11个与粒色相关的QTL,分别位于1号、2号、5号、6号、7号、8号和9号染色体上,单个QTL的表型贡献率为2.01%~29.25%,6个为主效QTL,其中,qSC1-2和qFLA1-1、qSC7-1和qFLA7-1、qSC9-3和qFLA9-1为2个性状下共同定位到的QTL。通过基因预测与功能注释,筛选出QTL置信区间内5个与类黄酮物质合成及代谢相关的候选基因,表明类黄酮物质的合成、代谢及利用相关基因极有可能控制了这些基因的表达。15个QTL分别聚集于7条染色体上,基于基因功能注释,共筛选了5个与谷子类黄酮合成及代谢相关的候选基因,表明不同QTL位点参与到了共同遗传机制,并可通过分子标记辅助选择进行类黄酮合成及代谢等有利基因的聚合育种。

金露梅不同药用部位6种黄酮类成分的含量比较

目的建立同时测定金露梅叶、花、果和枝4个不同药用部位黄酮类成分儿茶素、槲皮素-3-O-(6''-没食子酰基)-β-D-半乳糖苷、金丝桃苷、异槲皮苷、萹蓄苷和银锻苷含量的方法,并对不同部位含量结果进行比较。方法采用Agilent Poroshell 120 PFP色谱柱(4.6 mm×150 mm,2.7μm),以乙腈-0.1%磷酸水溶液为流动相进行梯度洗脱,切换检测波长分别为280 nm和354 nm,柱温为30℃,流速为0.8 mL·min^(-1)。采用柱状图及堆积柱状图表征不同药用部位6种化学成分的含量差异,Chiplot科研绘图平台对不同化学成分含量进行Spearman相关性分析。结果6种化学成分的总含量在不同部位的分布为:花>叶>果>枝,Spearman相关性分析结果表明,金露梅中异槲皮苷和金丝桃苷、异槲皮苷和银锻苷、金丝桃苷和银锻苷的含量具有较强的正相关性,相关系数分别为0.98、0.93和0.93。结论该研究结果可为金露梅质量控制、临床应用和资源的合理开发利用提供依据。

不同陈化方式对宛艾中酚酸类和黄酮类物质含量的影响

以酚酸中的新绿原酸、绿原酸、隐绿原酸、咖啡酸、异绿原酸B、异绿原酸A、异绿原酸C和黄酮类的棕矢车菊素、异泽兰黄素为指标,采用高效液相色谱仪(HPLC)研究宛艾自然陈化与加速陈化过程中酚酸类和黄酮类物质含量的变化。结果表明:在加速陈化过程中,大多数酚酸类物质含量增加,黄酮类棕矢车菊素含量逐渐减少,黄酮类异泽兰黄素含量明显增加;在自然陈化过程中,黄酮类物质棕矢车菊素、异泽兰黄素含量逐渐增加,酚酸类物质随陈化时间的增加变化各异。研究结果对宛艾大健康产品的开发具有一定的借鉴意义。

套袋遮光对欧李果实糖、酸和类黄酮含量的影响

【目的】考察不同光照强度及时间对欧李果实糖、酸和类黄酮含量的影响,为后期深入探讨光照影响果实品质的分子机制提供参考依据。【方法】以欧李品种‘农大6号’和‘农大7号’为试验材料,采用3种不同遮光率(30%、55%和100%)的果袋分别在果实膨大期和转色期进行套袋处理,测定其果实单果质量、可滴定酸含量、可溶性固形物含量和类黄酮含量。【结果】(1)两品种单果质量和果实可溶性固形物含量均表现为果实膨大期处理低于果实转色期处理,且均随果袋遮光率升高而逐渐降低。(2)‘农大6号’可滴定酸含量在套袋处理下均明显降低,且果袋遮光率越高、套袋时间越长,降酸效果越明显,而‘农大7号’可滴定酸含量受影响较小。(3)套袋‘农大6号’类黄酮含量均高于对照,并随果袋遮光率的增加先升后降,且膨大期处理高于转色期处理。套袋‘农大7号’类黄酮含量仅在果袋遮光率30%时显著高于对照,且膨大期处理显著低于转色期处理。【结论】套袋能有效改善欧李果实糖、酸和类黄酮含量,‘农大6号’以膨大期套袋为宜,‘农大7号’则以转色期套袋效果更好,且均以55%遮光率果袋对两品种糖、酸和类黄酮含量综合改善效果最佳。

淫羊藿中异戊烯基黄酮的鉴别和含量测定的综合实验设计

为加深学生对传统中药淫羊藿的药效成分异戊烯基黄酮的认识,设计了综合化学实验.将淫羊藿粉末经乙醇热回流提取,蒸馏浓缩得到总浸膏,再将总浸膏溶于水,依次用石油醚、乙酸乙酯和正丁醇萃取,得到石油醚相、乙酸乙酯相和正丁醇相.将三相的有机物分别用薄层色谱展开,在紫外灯下观察254 nm和365 nm荧光颜色和强度,同时用硫酸、氯化铁显色,表明各相均含有黄酮.以淫羊藿苷为标品,通过作标准曲线结合紫外光谱对其各相的异戊烯基黄酮含量进行平行测定,同时考察了方法的重复性和样品的稳定性.

不同来源金线莲组培苗中总黄酮、多糖和内酯苷含量分析

目的比较不同来源金线莲组培苗中总黄酮、多糖和内酯苷的含量。方法采用紫外分光光度法测定不同来源金线莲组培苗中总黄酮和多糖的含量,采用HPLC-ELSD法测定不同来源金线莲组培苗中2种内酯苷含量。结果不同来源金线莲组培苗中总黄酮含量范围为(8.21~16.50)mg·g^(-1),多糖含量范围为(41.40~112.89)mg·g^(-1),金线莲苷含量范围为(83.68~171.67)mg·g^(-1),3(R)-O-β-D-吡喃葡萄糖基-4-羟基-丁酸含量范围为(12.41~29.45)mg·g^(-1)。结论不同来源金线莲组培苗中总黄酮、多糖和内酯苷含量存在差异。

HPLC与紫外-可见分光光度法对翻白草中黄酮类成分含量测定

目的 建立测定翻白草中黄酮类成分含量的最佳方法。方法 先建立高效液相色谱法(HPLC)测定翻白草中的4种黄酮类物质含量的方法,其中流动相为乙腈与0.1%甲酸溶液,并采用梯度洗脱,柱温设为30℃,色谱柱为InertSustain C18(150 mm×4.6 mm, 5μm),检测波长设为360 nm,并对不同批次的翻白草中的4种黄酮类物质含量进行检测;选取芦丁作为对照品,以UV-VIS法测定翻白草中总黄酮含量。结果 不同产地的翻白草含有的黄酮类成分含量差异较大,总黄酮含量的差异也较大,建立的HPLC法与紫外-可见分光光变法(UV-VIS)法具有很好地重复性,样品稳定性好,且仪器精密度高,两种检测方法相结合能很好的把控翻白草品质。结论 以UV-VIS法对翻白草中的总黄酮进行测定,并采用HPLC法测定翻白草中含有的槲皮苷、芦丁、山柰酚和槲皮素,方法较为简便,且有很好的重复性、稳定性,精密度高,能很好地控制翻白草的品质,并为临床研究及其药理活性研究提供依据。