普洱茶抗氧化特性的初步研究

本研究用不同的有机溶剂,分步萃取普洱茶的水提物,得到氯仿萃取物、乙酸乙酯萃取物、正丁醇萃取物和萃取后剩余物。采用Fe^2-H2O2-鲁米诺的化学发光法和有机自由基二苯基苦基偕腙肼（DPPH）的分光光度法,比较各提取物的清除自由基的能力。结果 提示普洱茶水提物中的乙酸乙酯萃取层组分和正丁醇萃取层组分对DPPH和羟自由基均有较强的清除能力。     

苦丁茶提取物多酚含量与抗氧化活性的测定

首先用不同的有机溶剂分部萃取苦丁茶(Ilex kudincha C.J.Tseng)热水提取物(粗提物),得到氯仿萃取物、乙酸乙酯萃取物、正丁醇萃取物及萃取剩余物,然后采用Folin-Ciocalteu比色法测定粗提物和各萃取物的多酚含量,同时应用DPPH法、TEAC法和FRAP法分别测定粗提物和各萃取物的自由基清除能力和还原Fe3+能力。结果表明,苦丁茶提取物具有较高的多酚含量和较强的抗氧化能力;DPPH法和FRAP法测定各提取物抗氧化能力的结果为乙酸乙酯萃取物>正丁醇萃取物>粗提物>萃取剩余物>氯仿萃取物,TEAC法测定结果为乙酸乙酯萃取物>正丁醇萃取物>粗提物>氯仿萃取物>萃取剩余物;多酚含量与抗氧化能力之间、所用抗氧化测定方法之间均存在较好的相关性。     

普洱茶不同溶剂提取组分降脂减肥作用的比较研究

采用丙酮、水、氯仿、乙酸乙酯和正丁醇连续萃取普洱茶,旋转蒸发后冷冻干燥得到氯仿层、乙酸乙酯层、正丁醇层以及剩余水层4个主要分离组分,利用不同的组分灌胃经过肥胖造模处理的ICR小鼠,与普洱茶总水提取物和减肥药左旋肉碱进行比较,研究普洱茶不同组分对ICR肥胖小鼠的降脂减肥作用。实验结果表明,普洱茶总水提取物、乙酸乙酯萃取组分、剩余水层组分均对肥胖ICR小鼠具有很好的降脂减肥作用。其中乙酸乙酯层和剩余水层抑制脂肪累积（抑制率分别是24.7%和22.5%）的效果略差于减肥药物左旋肉碱（抑制率38.8%）,但在改善血清指标尤其是提高HDL-C水平方面（提高率为61.7%和73.4%）显著优于左旋肉碱（9.4%）,肝脏指标检测也得到了类似的结论,揭示普洱茶降脂减肥作用的主要成分可能存在于乙酸乙酯层和（或）剩余水层中。     

Antioxidant and Antifungal Activity of <Emphasis Type="Italic">Verbena officinalis</Emphasis> L. Leaves

The scavenging activity against DPPH (1,1-diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform, ethyl acetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of different fractions of 50% methanolic extract and some isolated compounds were also investigated. The results suggest that 50% methanolic extract and caffeoyl derivatives could potentially be considered as excellent and readily available sources of natural antifungal and antioxidant compounds.     

Studies on bioactivities of tea (Camellia sinensis L.) fruit peel extracts: Antioxidant activity and inhibitory potential against α-glucosidase and α-amylase in vitro

Tea fruit peel is the main byproduct during manufacture of tea seed oil. The great increase in tea seed oil production in recent years brings the challenge of finding application for tea fruit peel. The aims of this study were to obtain tea fruit peel extracts enriched with bioactive compounds by several solvent extraction methods and to evaluate their antioxidant activity and inhibitory potential against α-glucosidase and α-amylase in vitro. Flavonoids and phenolics were accumulated in ethyl acetate, butanol, and chloroform fractions, and these fractions possessed much better antioxidant activities, including scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) cation radicals (ABTS⁺), and reducing activity, compared with those of the 75% ethanol extract and water fraction. Moreover, the ethyl acetate, butanol, and chloroform fractions exhibited excellent inhibitory activity against α-glucosidase, much stronger than that of the positive control (acarbose). These fractions also showed mild inhibition on α-amylase activity.     

Bioactive properties and chemical constituents of methanolic extract and its fractions from Jatropha curcas oil

The present work is designed to evaluate the bioactive properties of the crude methanolic extract of Jatropha curcas oil and its solvent fractions. The crude methanolic extract obtained was fractionated using a hydrophilic lipophilic balanced (HLB) cartridge and then eluted with different solvents in the order of hexane (F1), dichloromethane (F2), chloroform (F3), ethyl acetate (F4) and methanol (F5), respectively. Total phenolic content of the crude methanolic extract and its fractions was in the range of 0.19-4.5 mg/g as gallic acid equivalent. Antioxidant activity of the crude methanolic extract and its fractions were determined by two complementary test methods, namely, phenanthroline method and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. All samples demonstrated weak antioxidant activity (150-851 μmol Fe/100 g of the extract and IC₅₀ of 1.05-13.5 mg/mL). When compared to butylated hydroxytoluene (BHT), a reference synthetic antioxidant, both showed weaker antioxidative potential. The evaluation of antimicrobial activity of the extracts was performed using a disc diffusion method and a micro-well dilution method against six economic plant disease bacteria. The results showed that all extracts possessed strong to moderate antibacterial activity with varying degrees of growth inhibition against the test bacteria. The minimum inhibitory concentrations (MIC) were in the range of 14.92-428.6 μg/mL. In addition, the chemical constituents in each fraction of the extract were subjected to analyze by gas chromatography-mass spectrometry (GC-MS). The eleven constituents were identified. Among them, 2,4-di-tert-butylphenol, methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and linoleic acid may be the main cause of its strong antibacterial activity. Therefore, this oil present in the methanolic extract had great potential as effective antibacterial sources.     

千层金叶片醇提物抗氧化活性的研究

为了探究千层金叶片醇提物的抗氧化活性,本文研究了千层金叶片醇提物及其不同极性部位的抗氧化活性和总多酚含量。研究结果表明：千层金叶片醇提物正丁醇相的总多酚含量最高,为(453.75±0.75) mg/g;75%甲醇粗提物及其正丁醇相对ABTS ⁺自由基的清除能力较抗坏血酸（VC）强;各组分还原力强弱顺序为VC>正丁醇相>75%甲醇粗提物>水相>乙酸乙酯相>BHT>石油醚相;正丁醇相和乙酸乙酯相对DPPH自由基的清除能力较醇提物和水相强,石油醚相最弱;千层金叶片醇提物及其不同极性部位清除ABTS ⁺自由基清除能力、DPPH自由基清除能力及还原力均与其总多酚含量呈正相关。除石油醚相外,千层金叶片醇提物及其不同极性部位均有较强的抗氧化活性,可作为一种良好天然抗氧化剂的物质来源。     

Efficacy of Plectranthus glandulosus (Lamiaceae) and Callistemon rigidus (Myrtaceae) Leaf Extract Fractions to Callosobruchus maculatus (Coleoptera: Bruchidae)

As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, methanol crude extracts of Plectranthus glandulosus and Callistemon rigidus leaves were sequentially fractionated in hexane, chloroform, ethyl acetate, and methanol to establish the most active fraction(s) against Callosobruchus maculatus in cowpea. Cowpea seeds (25 g) were treated with 0.5, 1, 2, and 4 g/kg of extract to evaluate the contact toxicity and F₁ progeny production of the beetles in the laboratory. Mortality was recorded 1, 3, and 7 d postexposure. P. glandulosus hexane fraction was more toxic than the other fractions recording 100% mortality at 4 g/kg, within 7 d with LC₅₀ of 0.39 g/kg. Hexane fraction of C. rigidus showed superior toxicity, causing 100% mortality at 4 g/kg within only 1 d of exposure with LC₅₀ of 1.02 g/kg. All the fractions greatly reduced progeny emergence, with C. rigidus hexane fraction being the best progeny inhibitor. Fractions of P. glandulosus and C. rigidus leaves had sufficient efficacy to be a component of storage pest management package for C. maculatus.     

普洱茶茶褐素的分级及相关性质初步研究

普洱茶水提物依次经氯仿、乙酸乙酯、正丁醇萃取后剩余的水层色素-茶褐素上羟丙基葡聚糖凝胶（sephadex LH-20）柱,以丙酮-水溶液进行洗脱,按照色素条带分别收集得到级分并初步研究它们的理化与光谱性质。结果表明,以40%丙酮-水溶液为洗脱剂,流速为0.05BV/h时,茶褐素的分级效果最好,柱中呈现6条明显的条带,它们的色差参数值、还原力、pH值、常规成分含量、紫外-可见光谱扫描、红外光谱扫描及稳定性等存在差异。该研究进一步表征了普洱茶茶褐素组成与性质的复杂性,同时为深入研究茶褐素的生物活性与化学成分的本质奠定了基础。     

茯砖茶不同萃取物对消化酶活性的影响

将茯砖茶依次用三氯甲烷、乙酸乙酯及正丁醇萃取后制备样品,测定各部分样品对α-淀粉酶及胰脂肪酶活性的影响。研究发现茯砖茶各部分样品对胰脂肪酶活性的影响程度不同,三氯甲烷层稍有抑制作用,活性只有对照的0.82倍,水提物、乙酸乙酯萃取层及正丁醇萃取层有显著的激活作用,正丁醇萃取层部分激活作用最明显,达2.54倍。茯砖茶各部分样品对α-淀粉酶活性均有激活作用,其中以乙酸乙酯萃取层部位的激活作用最强,激活倍数为4.09,其次是水提物,其激活倍数为2.99,水层的激活作用不显著。三氯甲烷萃取层抑制作用不显著,活性只有对照的0.88倍。乙酸乙酯萃取层及正丁醇萃取层部分经过HP-20树脂再分离后,各部分仍有较高的活性。     

普洱茶与红茶的抗氧化特性比较研究

采用氯仿,乙酸乙酯,正丁醇等溶剂,分步萃取普洱茶及红茶水提物。采用化学发光法和可见分光光度法比较两类茶水提物及萃取组分在水相和油相中的抗氧化性。结果表明普洱茶在水相中的抗氧化能力无论在总体或单个组分上均略低于红茶;两类茶水提物对某些油脂具有较好抗氧化性;乙酸乙酯萃取组分对两类茶在水相中的抗氧化性起主导作用,且红茶略高于普洱茶,在油相中均无表现明显抗氧化性。     

巴西橡胶树胶乳化学成分的GC-MS分析

采用气相色谱-质谱联用(GC-MS)技术,对巴西橡胶树胶乳氯仿、乙酸乙酯萃取物中的化学成分进行分析测定,结合计算机检索技术对其成分进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果表明,氯仿萃取物中共鉴定出33个化学成分,占总量的78.90%。乙酸乙酯萃取物中共鉴定出46个化学成分,占总量的90.15%。其中,τ-杜松醇、(Z)-金合欢醇、角鲨烯、环阿屯醇、24-亚甲基环木菠萝醇等萜类化合物及γ-谷甾醇、β-豆甾醇、菜油甾醇、异岩藻甾醇等植物甾醇在橡胶生物合成途径甲羟戊酸途径中作为中间体或终产物。除24-亚甲基环木菠萝醇以外,几种萜类和甾醇都具有一定药用作用,尤其是角鲨烯,具有抗癌、抗氧化、预防心血管疾病等生理活性,目前已成为天然药物研究的热点。     

Antiinflammatory screening of the medicinal plant Gynura procumbens

Gynura procumbens isused in Thai folk medicine to treat topicalinflammation, rheumatism, and viral ailments. In thepresent work, attempts were made to verify the folkmedicinal claim that the crude ethanolic extract ofG. procumbens has antinflammatory action and torelate the activity to particular fractions using acroton oil-induced mouse ear inflammation model. Theoriginal ethanolic extract of G. procumbens waspartitioned between water and ethyl acetate. Theresidues were subjected to antinflammatoryevaluation. While the water extract did not show anyantinflammatory activity, the administration of theoriginal organic extract significantly inhibited theincrease in ear thickness in response to crotonoil (n = 5). The activity of 0.75 mg/ear originalorganic extract showed similar antinflammatoryactivity (inhibition 65.2%) to that of 6 mg/earhydrocortisone 21-hemisuccinate sodium salt(inhibition 64.8%). The organic extract was thenfractionated with a series of solvents in order ofincreasing polarity. Each fraction was dried,dissolved in acetone and monitored using the samebioassay. These experiments showed that the hexaneand toluene fractions showed significant inhibitionsof 44.6% and 34.8%, respectively. These twofractions had similar activities to 4 mg/ear ofhydrocortisone (inhibition 35.0%). The possiblechemical constituents in the extracts and fractionswere investigated using thin layer chromatography andspecific color reagents. These tests showed thatsteroids might be one class of antinflammatorycompounds in this plant.     

嘉宝果嫩叶提取物不同极性部位抗氧化及抑制α-葡萄糖苷酶活性研究

从植物中寻找天然的抗氧化剂和α-葡萄糖苷酶抑制剂对糖尿病患者具有重要的意义。采用比色法对嘉宝果嫩叶醇提物不同极性部位进行总多酚和总黄酮含量、抗氧化活性及α-葡萄糖苷酶活性抑制活性研究,以期为嘉宝果嫩叶有效提取部位在食品、化工及医学领域的应用提供一定的参考依据。结果表明,乙酸乙酯相的总多酚含量（33.92 mg/g及总黄酮含量（13.35 mg/g）最高,其次为正丁醇相（总多酚31.11 mg/g;总黄酮12.93 mg/g）及水相（总多酚17.04 mg/g;总黄酮11.18 mg/g）;石油醚相及二氯甲烷相均未检测到总多酚及总黄酮。乙酸乙酯相与正丁醇相对DPPH及ABTS ⁺自由基的清除能力相当,明显高于其他极性部位。对酵母源和小鼠小肠源α-葡萄糖苷酶活性抑制活性大小依次分别为乙酸乙酯相>正丁醇相>水相>石油醚相>二氯甲烷相和乙酸乙酯相>正丁醇相>水相>二氯甲烷相>石油醚相。以上结果表明嘉宝果嫩叶乙酸乙酯相与正丁醇相总多酚及总黄酮含量较高,抗氧化活性及对α-葡萄糖苷酶活性的抑制作用较强,是挖掘抗氧化及抑制α-葡萄糖苷酶活性物质的主要极性部位。     

Efficacy of Lawsonia inermis leaves extract and its phenolic compounds against olive knot and crown gall diseases

This study was undertaken to determine the antibacterial efficacy of the leaves extracts of Lawsonia inermis in vitro and in vivo, against the phytopathogenic bacteria Pseudomonas savastanoi pv savastanoi IVIA 1628 and Agrobacterium tumefaciens. The hydroalcoholic extract of L. inermis was fractionated by liquid–liquid partition using hexane, chloroform, ethyl acetate and butanol. Among the tested fractions, the ethyl acetate (EtOAcF) and chloroform (CHCl₃F) extracts exhibited high inhibition against all tested plant pathogens. The extracts exerted a bactericidal activity against both P. savastanoi and A. tumefaciens with MIC values ranging from 1.25 to 2.5 mg/ml. In planta experiments, the EtOAcF, tested at four concentrations (0.4, 0.2, 0.1 and 0.05 mg/wounds), completely inhibited the formation of knots on twigs of olive and tomato plants inoculated with pathogenic strains of P. savastanoi and A. tumefaciens (strains B6 and C58). The phytochemical screening revealed that the L. inermis fractions contain flavonoids, quinones, tannins and terpenoids. The qualitative analysis of the EtOAcF by LC–DAD–ELSD–ESI/MSⁿ showed the presence of eight identified phenolic and phenolic glycoside compounds. These results suggest that L. inermis extracts could be used to control plant bacterial diseases caused by P. savastanoi and A. tumefaciens.     

Nitric Oxide Radical Scavenging Active Components From Phyllanthus emblica L.

An activity-directed fractionation and purification process was used to identify the nitric oxide (NO) scavenging components of Phyllanthus emblica. Dried fruit rind of P. emblica was extracted with methanol and then separated into hexane, ethyl acetate, and water fractions. Among these only the ethyl acetate phase showed strong NO scavenging activity in vitro, when compared with water and hexane phases. The ethyl acetate fraction was then subjected to separation and purification using Sephadex LH-20 chromatography. Five compounds showing strong NO scavenging activity were identified by spectral methods (¹H NMR, ¹³C NMR, and MS) and by comparison with literature values to be Gallic acid, Methyl gallate, Corilagin, Furosin, and Geraniin. In addition, HPLC identification and quantification of isolated compounds were also performed. Gallic acid was found to be a major compound in the ethyl acetate extract and Geraniin showed highest NO scavenging activity among the isolated compounds.     

The influence of the growth season on the antimicrobial and antioxidative activity in Artemisia princeps var. orientalis

We investigated the influence of the growth season of Artemisia princeps var. orientalis (P_AMPAN.) H_ARA on antimicrobial and antioxidative activities. The ethyl acetate and water fractions of crude methanol extract from the plant collected monthly (April through October) were tested against three gram-positive, two gram-negative bacteria and one lactic acid bacterium. The ethyl acetate and water fractions of crude methanol extract from A. princeps var. orientalis collected in August and September had the highest antimicrobial activity. The antimicrobial activity of extract from A. princeps var. orientalis for Lactobacillus plantarum was not found at any concentration and in any growth season. Minimum inhibitory concentration (MIC) for each strain by ethyl acetate fraction of methanol extract from A. princeps var. orientalis was different depending on the tested strain and growth season of the plant. MIC for each strain was the highest in the sample from April, followed by October. The antioxidative activities of methanol extracts from A. princeps var. orientalis collected monthly were measured by their scavenging activity on free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and xanthine oxidase (XO) inhibitory activity. The DPPH radical scavenging activities of the extracts from the plants collected in May, June and July were higher than any other. The XO inhibitory activities of the extracts of A. princeps var. orientalis collected in April and May showed the greatest activity, it is different with antimicrobial activity. This is the first report that antimicrobial and antioxidative activity of the extracts of A. princeps var. orientalis is different with growth season.     

水黄皮中水黄皮素的提取及其对桔小实蝇的杀虫活性

桔小实蝇是一种毁灭性害虫,可为害200多种水果,目前其防治方法或毒性大,对环境不友好,或成本高昂。本研究拟采用廉价易得的水黄皮荚果为原料,采用超声波辅助提取法,单因素试验比较乙醇浓度,乙酸乙酯、石油醚、正己烷和乙醇的料液比对水黄皮荚果中水黄皮素提取率的影响,得出最优溶剂及其料液比;再分别采用浸渍法和叶碟法测定其提取物对桔小实蝇的卵孵化抑制活性和对1龄幼虫的胃毒活性。结果表明,乙醇最佳提取浓度为60%,乙酸乙酯、石油醚、正己烷与60%乙醇的最佳料液比分别为1∶30、1∶20、1∶30和1∶25,提取率分别为0.48%、0.31%、0.37%和0.44%,即1∶30乙酸乙酯的提取效果最好。杀虫活性研究表明,2%水黄皮提取物对桔小实蝇的卵孵化抑制作用最强,校正孵化抑制率为58.53%,6%提取物对卵孵化抑制作用次之,校正孵化抑制率为46.46%;4%提取物对桔小实蝇1龄幼虫胃毒活性最好,24 h校正死亡率为54.05%,48 h校正死亡率为95.94%。以乙酸乙酯为溶剂,料液比1∶30时,水黄皮中水黄皮素的提取效果最好,其提取率是0.48%。水黄皮提取物对桔小实蝇的卵孵化有抑制作用,对1龄幼虫有胃毒活性,因此有望开发为针对桔小实蝇的植物源杀虫剂。     

Chemical composition and anti-fungal properties of the essential oils and crude extracts of Orthosiphon stamineus Benth

The hydrodistilled essential leaves and stems oils of Orthosiphon stamineus Benth were analysed by GC–MS/MS. Sixty nine compounds representing 97.6 and 97.4% of the total leaves and stems oils, respectively were identified, of which β-caryophyllene (24.0 and 35.1%), α-humulene (14.2 and 18.4%), β-elemene (11.1 and 8.5%), 1-octen-3-ol (8.2 and 7.0%), β-bourbonene (3.4 and 3.0%), β-pinene (2.1 and 1.7%), caryophyllene oxide (1.6 and 2.2%), camphene (1.6 and 1.3%) and limonene (1.2 and 1.1%) were the major compounds. Thus, the monoterpenes and sesquiterpenes were the predominant portions of the oils. Essential oils and methanol extract of O. stamineus and the derived fractions of hexane, chloroform, and ethyl acetate were tested for anti-fungal activity, which was determined by disc diffusion and minimum inhibitory concentration (MIC) determination methods. The oils, methanol extract and derived fractions of methanol extract displayed great potential of anti-fungal activity as a mycelial growth inhibitor against the tested phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium solani, Colletotricum capsici and Phytophthora capsici, in the range of 49.3–70.3% and minimum inhibitory concentration ranging from 500 to 1000 μg/ml.     

Antioxidant activity of phenolic compounds obtained by autohydrolysis of corn residues

This study aimed to evaluate the effect of autohydrolysis temperature of corn residues in the antioxidant activity of the phenolic compounds extracted from the liquid phase. The treatments were carried out at 160, 180, 190 and 200 °C for 30 min in a pressurized batch reactor. Two different methods for phenolic compounds extraction from the autohydrolysis liquors were investigated. For that purpose, solvent extraction with ethyl acetate and acidic precipitation were performed for phenolic compounds recovery. These methods have been compared in terms of extraction yield, physicochemical properties of obtained polyphenols (characterization by Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis and Gel Permeation Chromatography), total phenolic content, total antioxidant capacity and Trolox equivalent antioxidant capacity (TEAC) values, measured in DPPH (2,2-diphenyl-1-picrylhydrazyl) test system. The maximum phenolic contents ranged from 6.04 mg GAE/100 mg extract in acidic precipitated samples to 16.45 mg GAE/100 mg extract in ethyl acetate soluble fractions. The results indicated that the ethyl acetate fractions possessed the highest antioxidant activity, reaching after 30-60 min the same capacity reported for the reference synthetic antioxidants (Trolox).