琼榄提取物的抗氧化及抗菌活性初步研究

为研究琼榄的药用活性成分,更好地开发和利用琼榄资源,对琼榄根、茎、叶的5种不同溶剂提取物分别采用清除DPPH自由基法和滤纸片扩散法进行抗氧化及抗菌活性研究。结果表明,琼榄叶的乙酸乙酯提取物（L-EtOAc）清除DPPH自由基的IC50最小,为154.1μg/mL,是15组提取样品中清除自由基活性最强的部位。琼榄根、茎、叶的15组提取物对5种供试菌均具有不同程度的抑菌活性,且以琼榄叶的乙酸乙酯提取部位对5种供试菌的抑菌作用均较强,特别是对金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌的抑制作用和阳性对照品头孢他啶的抑菌作用接近。因此,琼榄叶部位的抗氧化和抗菌活性最强,且活性物质在乙酸乙酯部位,L-EtOAc为有效提取部位。     

龙眼叶乙酸乙酯提取物抗氧化活性研究

采用DPPH自由基和羟自由基体系评测龙眼叶乙酸乙酯提取物抗氧化活性,为龙眼叶的开发与应用提供参考数据。方法:将龙眼叶用乙酸乙酯冷侵提取,旋转蒸发得到龙眼叶乙酸乙酯提取物,采用苯基苦味肼基自由基(DPPH)法与还原能力测定法,对其提取物进行自由基清除能力评定。结果:龙眼叶乙酸乙酯提取物对DPPH自由基与羟自由均具有较强清除能力,其中对DPPH自由基的清除能力可高达46.14%。结论:龙眼叶乙酸乙酯提取物不仅具有一定的抗氧化活性和优异的自由基清除能力,其还原能力与乙酸乙酯提取浓度还存在一定量效关联。     

铁皮石斛炮制前后的护肤功效研究

采用石油醚、乙酸乙酯和正丁醇萃取的方式提取炮制前后的铁皮石斛茎条醇提物中的活性物质,分析比较其炮制前后三种提取物的抗氧化活性和酪氨酸酶抑制作用。研究表明:铁皮石斛茎条炮制前后醇提物的三种萃取物均有一定的DPPH自由基清除能力和酪氨酸酶抑制作用,但炮制后的铁皮石斛茎条DPPH自由基清除能力和酪氨酸酶抑制作用均比未炮制的茎条有明显提升,且乙酸乙酯萃取部分活性最佳。     

薏苡茎乙酸乙酯提取物抗氧化性研究

以薏苡茎为对象,研究薏苡茎乙酸乙酯提取物抗氧化活性。薏苡茎经乙酸乙酯加热回流后提取其有效成分,采用紫外分光光度法测定其抑制超氧阴离子(O-2·)的能力、清除DPPH·自由基的能力以及用丁基羟基茴香醚(BHA)作对照测定其对Fe2+的螯合能力。结果表明薏苡茎乙酸乙酯提取物有较强的清除DPPH·自由基的能力、清除超氧阴离子(O-2·)的能力、螯合金属离子Fe2+的能力。因此薏苡茎乙酸乙酯提取物具有较强的抗氧化性。     

红花酢浆草抗氧化活性研究

采用DPPH法分别对红花酢浆草的根茎、叶子、花等部位的极性提取物进行抗氧化活性测试,结果表明,随着提取物浓度的增大,其对DPPH自由基的清除能力越强;其中红花酢浆草根茎的乙酸乙酯提取物对DPPH的清除率达90%以上。红花酢浆草的根茎、花、叶均具有良好的抗氧化活性,以酢浆草根茎最为突出。     

阔叶十大功劳叶不同萃取相抗氧化活性的研究

为了确定阔叶十大功劳叶的生物活性物质,采用有机溶剂萃取法将阔叶十大功劳叶提取物分为正己烷相、二氯甲烷相、乙酸乙酯相、正丁醇相和水相5个不同极性相态,测定不同极性溶剂提取物中总黄酮及多酚含量,分析其还原能力及对DPPH自由基的清除能力,比较十大功劳提取物不同极性溶剂提取物的抗氧化作用。结果显示:十大功劳提取物的不同极性溶剂抗氧化活性作用差异显著,其中乙酸乙酯部位提取物和正丁醇部位提取物抗氧化能力较强于其它萃取相部位。     

液态发酵茯苓菌有机相提取物抗氧化活性研究

用液态发酵技术培养茯苓菌获得菌丝，用甲醇溶出和加热回流、乙酸乙酯加热回流3种提取方式取得不同三萜产物，考察这三种三萜产物对常见自由基DPPH、H₂O₂的抗氧化活性。结果显示，这3种三萜产物对自由基DPPH、H₂O₂有显著的消除能力，且以甲醇加热回流提取的茯苓三萜产物消除能力最强。     

乌蔹莓不同溶剂提取物抗氧化活性研究

目的:研究乌蔹莓不同溶剂提取物的体外抗氧化活性,为乌蔹莓的开发利用提供科学依据。方法:药材经95%乙醇超声提取,醇提取物用不同极性溶剂进行萃取分离,得到石油醚、乙酸乙酯、正丁醇及水4个不同极性萃取部位。以维生素C(VC)作为阳性对照,采用DPPH法、ABTS法和普鲁士蓝法分别测定不同浓度各部位的自由基清除能力和铁离子还原力。结果:乌蔹莓不同溶剂提取物均具有一定的体外抗氧化作用,且在相同浓度下,乙酸乙酯部位的抗氧化活性最强,其次是正丁醇部位和乙醇总提物。乙酸乙酯萃取物的铁还原力最显著。结论:在一定范围内,乌蔹莓各提取物清除能力与其样品浓度具有良好的量效关系,其中乙酸乙酯萃取物和乙醇总提取物抗氧化能力较强,是天然抗氧化剂的良好来源。     

艾渣不同极性部位的体外抗氧化活性

为考察艾渣不同极性溶剂提取部位的体外抗氧化活性,用紫外分光光度法对以石油醚、氯仿、乙酸乙酯、正丁醇和水为溶剂的5个不同极性部位萃取物中总黄酮含量进行测定,并以抗坏血酸(VC)为阳性对照,采用DPPH、ABTS自由基清除法和Fe~(3+)还原法(FRAP法)测定艾渣不同极性部位的体外抗氧化作用。结果表明,艾渣中黄酮类物质偏中等极性,多富集于乙酸乙酯及氯仿部位。艾渣提取物的不同极性部位均有不同程度的体外抗氧化效果。其中乙酸乙酯部位的DPPH及ABTS自由基清除率最强[IC_(50)值分别为(0.115±0.003) g/L和(0.093±0.003) g/L],正丁醇及氯仿部位的DPPH及ABTS自由基清除率次之。水层还原Fe~(3+)的能力最强,其次为正丁醇与乙酸乙酯部位。石油醚部位在三个抗氧化试验中均表现出较弱的抗氧化性。因此,初步推测抗氧化活性多集中于乙酸乙酯与正丁醇部位,可以将其作为抗氧化剂添加到化妆品中。     

甘蔗花与叶抗氧化活性研究

为了探明农作物甘蔗花和甘蔗叶提取物的抗氧化活性。以甲醇和乙醇为溶剂,采用超声提取法对甘蔗花及甘蔗叶进行提取,考察其对DPPH自由基活性的清除能力,并与多种抗氧化剂的清除能力进行比较。甘蔗花和甘蔗叶的提取物与5种标准品的抗氧化能力对比为:没食子酸咖啡酸芦丁甘蔗花甲醇提取物香草酸甘蔗叶甲醇提取物甘蔗花乙醇提取物甘蔗叶乙醇提取物对香豆酸。结果表明,甘蔗花的甲醇提取物抗氧化能力大于香草酸、对香豆酸两种标准品,因此具有一定的抗氧化能力。     

落地生根萃取物的抑菌活性

[目的]比较落地生根根、茎、芽和花各萃取相提取物的抑菌活性,进一步明确起抑菌作用的活性成分,为以后的分离打下基础.[方法]以番茄早疫病菌、水稻立枯病菌为指示菌,采用生长速率法和孢子萌发法,测定各自的抑菌活性.[结果]落地生根芽氯仿萃取物对2种菌的菌丝生长和孢子萌发具有较好的抑制作用,菌丝生长抑制率分别为92.41%和89.22%,孢子的萌发抑制率依次为91.85%、86.11%.[结论]芽氯仿相萃取物的抑菌效果最好,表明落地生根植物中起抑菌作用的活性成分主要集中在芽部位,且抑菌活性成分主要为弱极性物质.     

几种植物的杀虫活性初探

首次报道黄连（根）和菟丝子（种子）的杀虫活性。用1％浓度的甲醇提取物处理试虫后，所筛选的植物巾菟丝子种子和李叶绣线菊茎的甲醇提取物对家蝇48h的毒杀作用强，分别为100．00％和75．86％，单面针叶和阔叶十大功劳茎叶也有较好的毒杀作用，分别为58．62％和67．86％。黄连根甲醇提取物24h和大叶醉鱼草茎叶甲醇提取物48h对亚洲玉米螟3龄幼虫的拒食率分别为76．48％和76．50％，且出现虫体细且短小、头部宽大、与腹部极不对称和化蛹延迟现象，大黄和阔叶十大功劳也表现出一定的毒杀或拒食或抑制生长发育现象。所筛选的特有植物对赤拟谷盗种群的毒杀作用和繁殖抑制作用较低。毒杀作用最强的为大叶醉鱼草茎叶，处理后30d，赤拟谷盗的死亡率为40．16％，繁殖抑制率最强的为黄连根，处理后60d，繁殖抑制率为46．38％。以甲醇冷浸提取法对所采集的植物材料进行冷浸提取时，提取率分布在1．41％～7．06％之间。     

紫苏全草抗菌活性的研究

对紫苏全草分部位、分萃取段进行了抗菌活性研究。选择革兰氏阳性菌中的金黄色葡萄球菌和革兰氏阴性菌中的大肠杆菌为代表菌种,筛选出了对所选细菌的生长具有明显抑制作用的抗菌活性部分:紫苏叶的石油醚萃取物,紫苏叶、茎、根的乙酸乙酯萃取物,在LB培养基中,它们对金黄色葡萄球菌的抑菌圈半径分别为6、8、4、2mm;对大肠杆菌的抑菌圈半径分别为1 5、3、2、0mm。结果表明,紫苏叶的乙酸乙酯萃取物对两种细菌的抑菌活性最强。采用薄层色谱(TLC)预试法对抗菌活性部位进行了有效化学成分分析,结果表明,紫苏全草抗菌活性成分主要为:挥发油、黄酮、酚、有机酸、香豆素内酯等化合物。     

油茶叶多糖的闪式提取工艺优化及其抗氧化活性

在单因素试验基础上用响应面法对油茶叶多糖的闪式提取工艺进行优化,并对较优条件下提取的多糖的抗氧化活性进行测试。研究结果表明：油茶叶多糖闪式提取的较佳工艺条件为料液比1：30（g：mL）,提取温度81℃,提取时间75 s,此条件下,油茶叶多糖得率为8.43%。油茶叶多糖对DPPH·、·ABTS⁺、OH·都有很强的清除能力,其半数抑制浓度（IC₅₀）值分别为1.706、0.826和4.811 g/L,表现出很好的抗氧化活性。     

藤茶黄酮绿色制备纳米氧化锌及其抗氧化和抗菌性能

以藤茶黄酮为原料,采用溶液燃烧法绿色制备纳米氧化锌(Nano ZnO)粉末,并利用FTIR、XRD、SEM和EDS对所得样品进行结构分析和形貌观察;使用布兰德-威廉姆斯法、透明抑菌圈法和最小抑菌浓度法考察了绿色合成Nano ZnO的抗氧化性能和抑菌性能。结果表明,以藤茶黄酮为生物模板制备的Nano ZnO粒子为六方晶系纤锌矿结构,结晶度良好,晶粒平均尺寸约为32.7nm;该纳米材料具有良好的抗氧化活性,2.5g/L的Nano ZnO溶液对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除率为98.24%;藤茶黄酮绿色合成Nano ZnO对金色葡萄球菌的抑菌活性高于传统化学合成的Nano ZnO。绿色合成Nano ZnO的最小抑菌浓度为1.00 g/L,而化学合成Nano ZnO的最小抑菌浓度为1.50 g/L。     

9种药用植物内生或附生真菌的分离及其杀虫、抑菌活性

从9种药用植物的根、茎、叶、花中分离得到358株内生或附生真菌,其中9株真菌的发酵液对白纹伊蚊3龄幼虫的毒杀活性较强,24 h死亡率均达到80%以上;15株真菌的发酵液对至少1种供试病原真菌的菌丝生长抑制率超过50%;4株真菌的发酵液对5种供试细菌均有明显的抑菌活性.     

Antioxidant Properties of Three Aromatic Herbs (Rosemary, Thyme and Lavender) in Oil-in-Water Emulsions

Lipid oxidation is the major form of deterioration in foods because it decreases food quality and nutritional value, and may have negative health implications. Selected aromatic plant extracts from leaves, flowers and stems of rosemary, thyme and lavender were investigated for their antioxidant activity. The total polyphenol content was determined by the Folin–Ciocalteu assay and the antioxidant capacity was determined by the Trolox equivalent antioxidant capacity, 1,1-diphenyl-2-picrylhydrazyl, oxygen radical absorbance capacity and ferric-reducing antioxidant power assays. For all four antioxidant assays, the extracts from thyme flowers, lavender leaves and thyme leaves had the highest antioxidant activity, followed by rosemary stems, rosemary leaves, and lavender stems, and the lavender flowers and thyme stems had the lowest antioxidant activity. The antioxidant activity was correlated with the polyphenol content, although minor deviations were observed. In oil-in-water emulsion, extracts from rosemary leaves and thyme leaves were most effective at retarding oxidation followed by the rosemary stems and thyme flowers. Extracts from thyme flowers and lavender leaves were less effective in the emulsion than predicted by the homogeneous antioxidant assays. This study demonstrated the potential use of plants extract as substitutes for synthetic antioxidants.     

Antioxidant, antimicrobial and antiproliferative activities of five lichen species

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells.     

桑叶乙醇提取物的体外抗氧化与抑菌活性

采用索氏提取法对干桑叶进行提取,得到乙醇提取物,并对提取物的组分以及体外抗氧化活性和抑菌活性进行了测定。研究结果表明：桑叶乙醇提取物中含有多种有机物,主要包括酯类(82.85%)、烷烃类(6.31%)、芳烃类(1.62%)和醇类(0.21%)。桑叶乙醇提取物总还原力与浓度有显著的线性关系;对DPPH自由基和OH自由基都有良好的清除能力,半数抑制浓度(IC₅₀)分别为73.07和104.52 mg/L。桑叶乙醇提取物对枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌均具有一定的抑制作用,抑制效果为枯草芽孢杆菌＞金黄色葡萄球菌＞大肠杆菌,IC₅₀分别为4.824、6.806和14.382 g/L。桑叶乙醇提取物的抗氧化活性和抑菌活性随样品浓度的增大而增大。     

Flavonoid and Phenolic Acids Content and In Vitro Study of the Potential Anti-Aging Properties of Eutrema japonicum (Miq.) Koidz Cultivated in Wasabi Farm Poland

Skin aging is a natural, unavoidable, and complex process caused by oxidative stress. As a consequence, it leads to an increase in the activation of extracellular matrix disruption enzymes and DNA damage. The search for natural sources that inhibit these mechanisms can be a good approach to prevent skin aging. The purpose of our study was to evaluate the composition of flavonoids and phenolic acids in the extracts obtained from the flowers, roots, and leaves of Eutrema japonicum cultivated in Poland. Then, the resultant extracts were subjected to an assessment of antioxidant, anti-collagenase, anti-elastase, anti-hyaluronidase, antibacterial, and cytotoxic properties. It was demonstrated that the extract from the flowers had the highest content of flavonoid glycosides (17.15 mg/g DE). This extract showed the greatest antioxidant, anti-collagenase, anti-elastase, and anti-hyaluronidase activities compared to the other samples. Importantly, the collagenase inhibitory activity of this extract (93.34% ± 0.77%) was better than that of positive control epigallocatechin gallate (88.49% ± 0.45%). An undeniable advantage of this extract was also to possess moderate antibacterial properties and no cytotoxicity towards normal human skin fibroblasts. Our results suggest that extracts from E. japonicum flowers may be considered as a promising antiaging compound for applications in cosmetic formulations.