印楝素微波萃取技术研究

印楝素(Azadirachtin)是从印楝(Azadirachta indica A.Juss)种仁中分离得到的柠檬素类(limonoids)化合物,属四环三萜类化合物[1].生物活性试验证明低浓度的印楝素即对沙漠蝗(Schistocera gregaria)产生强烈的拒食活性,进一步的研究证明印楝素对多种农林业害虫具有较高的拒食、趋避及抑制生长发育等作用[2],且具有害虫不易产生抗性、对温血动物无害、对昆虫的天敌较安全、在自然界易降解等特点,其广泛应用有利于生态平衡及农林业的可持续发展,是一种有广阔应用前景的植物源生物农药.     

Ag(Ⅰ)Schiff碱配合物的合成及其对黄瓜花叶病毒的抑制作用

黄瓜花叶病毒 (Cucumber mosaic virus,CMV)是多种双子叶和单子叶作物减产的主要病害 ,且易经汁液和蚜虫传毒 ,危害极大 [1] 。 Christopher[2 ] 和吴尔福等 [3 ] 对抗植物病毒的植物种类及治疗作用进行了研究。我们从抑制植物病毒的数十种植物提取液中筛选出对 CMV具有抑制作用的水杨酸苯丙胺类化合物等有效成分 [4 ] 。本文根据 Schiff碱及其配合物具有抑菌、抗病毒等 [5,6] 生物活性的特点 ,合成了一系列对 CMV具有较好抑制作用的新型氨基酸 Schiff碱 Ag( )配合物。PE2 4 0 0 元素分析仪 (美国 ,PE公司 ) ;Perkin- Elmer 783红…     

N-烟酰基壳寡糖的合成及其诱导烟草抗病毒作用

壳寡糖(chitooligosaccharides,COS)是聚合度为2-20的低聚β-(1,4)-2-脱氧-2-氨基葡萄糖,具有抑菌[1][2]、植物诱抗[3]、提高免疫力[4]、抑制肿瘤[5]、抑制血管紧张素转化酶[6]和降血脂[7][8]等多种生物功能。壳寡糖可生物降解、无毒,其诱导抗病活性已成功应用于多种植物病害的     

青蒿挥发油化学成分的分析测定

青蒿[1]Artemisia annua L.又名香蒿,为菊科植物青蒿或黄花蒿的全草.分布辽宁、河北、山东、山西、江苏、广东等地.青蒿在我国各地均有大量野生,资源丰富,本植物的根(青蒿根),果实(青蒿籽)均可供药用,青蒿具有抗疟、抗血吸虫、解热、镇痛及退虚热、和胃止痛等功效.青蒿的主要成分有苦味质、挥发油和青蒿碱、维生素A等.为探讨其挥发油的成分,我们对青蒿全草进行挥发油的提取,并用GC-MS进行测定分析,从中鉴定出44个化合物.     

川明参茎叶中的化学成分

川明参 ( Chuanminshen violaceum Sheh et Shan)属于伞形科川明参属 ,在形态上与明党参相近 ,是我国特有的单种属植物 ,主要分布在四川 ,多为栽培 [1] .其根作为滋补药材 ,具有润肺化痰、和胃生津和解毒等功效 .饶高雄 [2 ] 及周燕等 [3] 曾对不同产地的川明参根部化学成分进行了研究 ,分离鉴定出的主要成分为芦丁和多种香豆素 .为了进一步探索川明参的活性成分以及对川明参资源的综合开发利用 ,我们对一般弃置不用的川明参茎叶的化学成分进行了研究 ,从其水煮提取物中分离得到 8个化合物 ,通过波谱分析鉴定了其中 7个化合物 ,它们是 4-…     

防治害虫的植物自身保护机制

美国加利福尼亚大学科学家的一项新研究证实 ,植物受害虫攻击时启动的一种自身保护机制能使害虫更容易被其天敌消灭。这一机制有可能用于研究更有利于环保的害虫防治新方法。研究人员用人为方法刺激西红柿自身保护机制发挥作用 ,结果发现危害西红柿生长的甜菜夜蛾被天敌寄生蜂杀死的数量成倍增加。植物自身保护机制由一系列复杂的化学反应构成 ,害虫攻击植物会启动这些反应。甜菜夜蛾咬噬西红柿时 ,西红柿首先会产生茉莉酮酸 ,随之进一步产生其它具有特殊气味的化学物质 ,将此处存在害虫的信息“通知”寄生蜂。寄生蜂通过触角嗅到这些气味后…     

油菜叶片中硫甙总量与分量的HPLC测定

硫甙是一类含硫次生代谢产物,广泛存在于芸薹属植物。油菜中常见的硫甙成分有近20种,研究表明,油菜籽硫甙含量降低后,其植株抗性也明显下降,油菜种子、茎、叶的硫甙含量受不同基因型控制[1]。油菜种子中硫甙含量及组分的检测技术已有很多报道[2-6],李培武等[5-7]建立了胶束电动     

印楝素B的结构修饰研究

印楝素(Azadirachtin)是从印楝(Azadirachta indica A.Juss)种仁中分离得到的一系列柠檬素类(limonoids)化合物[1],主要含AZ-A至AZ-L等十余种活性组分.印楝素对多种农林业害虫具有拒食、趋避及抑制昆虫生长发育等作用,且具有害虫不易产生抗性,对天敌较安全、对温血动物无害、在自然界易降解、不污染环境等特点,其广泛应用有利于生态平衡及农林业的可持续发展[2,3],是一种有广阔应用前景的生物农药.     

改装简易蒸馏法提取侧柏挥发物的GC-MS分析

植物挥发性次生物质是自然界中昆虫寻找寄主的主要信息化合物,因此近年来植物挥发物的有效提取成为昆虫引诱剂开发研究的热点.目前常用于提取植物挥发性次生物质的方法有索氏提取法[1]、水蒸汽蒸馏法和超临界萃取法等[2].     

紫外分光光度法测定2,4-二氯苯酚

2,4-二氯苯酚被世界野生动物基金会列为潜在的内分泌修正化学物质,即环境荷尔蒙物质.这类物质在环境中虽然含量低,但却显示出超常的内分泌效应,因而对其的监测分析显得尤为重要.目前,分析2,4-二氯苯酚的方法有比色法[1]和色谱法[2].色谱法虽然快速、准确,但对仪器要求高,操作复杂,而比色法灵敏度低.用紫外分光光度法测定河水中的2,4-二氯苯酚.     

The effect of harvest periods on the chemical compositions of essential oils of sage (Salvia aucheri L.) leaves

The essential oils of sage leaves (Salvia aucheri Bentham var. canescens Boiss. & Heldr.), growing wild in South Anatolia, were extracted by hydrodistillation and analysed by GC and GC-MS. The percentage yields of the essential oils from sage leaves harvested at different years were 1.0%, 1.3%, 1.3%, 1.0%, 1.4%, 1.5% and 1.2%, respectively. In this study, 1,8-cineole, camphre, camphene α-pinene and β-pinene were identified as the major components of sage leaves collected at different periods. The main constituents of sage oil collected over the years were 1,8-cineole (35.01-48.06%), camphre (13.58-23.92%), camphene (6.77-8.82%), α-pinene (5.79-8.54%) and β-pinene (4.32-6.28%).     

Analysis of volatile components of Lavandula luisieri L. by direct thermal desorption-gas chromatography-mass spectrometry

Volatile components of wild samples of Lavandula luisieri collected in Central and Southern Spain have been analyzed by direct thermal desorption coupled to gas chromatography-mass spectrometry (DTD-GC-MS). This method requires only 10-20 mg of dry sample, allowing to obtain qualitative and quantitative results from different plant parts such as flowers and leaves. Average volatile yield calculated from 51 individual plants was higher for leaves (9.7mg g(-1)) than for flowers (2.9mg g(-1)). Samples presented a high variation in their yield and composition. Major components were camphor and 1,8-cineole (up to 80.9 and 76.7% in leaves; 87.8 and 85.2% in flowers, respectively); however, these compounds were not detected in several samples. Other major component (up to 60% in flowers and leaves) was 2,3,5,5-tetramethyl-4-methylene-2-cyclopenten-1-one. Multivariate analysis was applied to quantitative data from nine selected compounds in order to show the presence of several patterns in plant composition which were only partially related to the site of collection.     

The volatile constituent analysis of Digitalis nervosa Steud. & Hochst. ex Benth. from Iran

Russian Chemical Bulletin - The volatile constituents of the leaves of Digitalis nervosa Steud. & Hochst. ex Benth. growing wild in Iran was reported for the first time. The essential oil...     

攀枝花地区野生番石榴叶提取物中Zn、Mg、Cr、V等微量元素分析

采用电感耦合等离子体发射光谱仪(ICP-AES)同时测定了攀枝花地区野生番石榴叶水和乙醇提取物中Zn、Mg、Cr、V等微量元素的含量。结果表明,攀枝花地区野生番石榴叶中富含Zn、Mg、Cr、V等微量元素,水提取物和不同浓度乙醇提取物中Zn、Mg、Cr、V等微量元素含量不同。     

Metals content of soil,leaves and wild fruit from Serbia

The concentrations of Zn, Mn, Fe, Pb, Ni, Cu and Cd in soil, leaves and edible wild fruit (Crataegus laevigata L., Cornus mas L. and Prunus spinosa L.) from southeast Serbia were determined by atomic absorption spectroscopy. Metal translocations from soil to fruit were calculated as well as their oral intake and health risk indices. Positive correlations were found among metal concentrations in soil, leaves and fruit.      

Content of selected secondary metabolites in wild hop

We focused on the determination of biologically active secondary metabolites in wild hops over the course of the vegetation period in four selected sites in Pie??any. Hop was collected in four collection periods in 2010. The objects of research were the leaves of male and female plants, and female cones. Analysis of the extracts from wild hop confirmed differences in total content of polyphenols, flavonoids between the localities and in the growing seasons over the vegetation period. The extracts from leaves from the first harvest in localities “gSládkovi?ova” and the river Vah showed higher levels of polyphenols (4.91–6.93 mg g^?1 of dry mass), flavonoids (2.28–2.99 mg g^?1 of dry mass) than the extracts from cones collected at the end of the vegetation period (polyphenols 3.63–5.33 mg g^?1 of dry mass, flavonoids 1.86–2.16 mg g^?1 of dry mass). The extracts from leaves from the first harvest from the “tennis court” site showed lower values of polyphenols and flavonoids. Our findings were that the leaves from the first harvest at the beginning of the growing season contained higher amounts of the secondary metabolites investigated than the cones at the end of the growing season. The content of α-bitter acids in wild hop cones ranged from 1.64 % to 2.91 %, in leaves from 0.11 % to 0.99%. Concentration of β-bitter acids in cones varied from 1.63 % to 1.93 % and in leaves from 0.02 % to 0.61 %.     

Isolation of C-glycosyl xanthones from Coffea pseudozanguebariae and their location

The biochemical composition of leaves from Coffea pseudozanguebariae, a wild caffeine-free coffee species, was determined. Two phenolic compounds were extracted from leaves, separated and characterized. Their structures were elucidated by mass spectrometry, and 1D and 2D NMR spectroscopy and were shown to be mangiferin (1) and isomangiferin (2), which were the main polyphenol products. Multiphoton fluorescence imaging was performed to visualize polyphenol distribution in leaf cross sections. Consistent biochemical analysis cell imaging techniques on leaves revealed yellow fluorescence in the epidermis and parenchyma cells corresponding to xanthone compounds.     

Evaluation of volatile constituents of Cochlospermum angolense

The chemical composition of the essential oils obtained from the leaves and roots of Cochlospermum angolense (Welw) growing wild in Angola was analyzed for the first time by capillary gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The investigation led to the identification of 67 and 130 compounds from the leaves and roots, respectively. Both oils were strongly characterized by the presence of sesquiterpenoids (68.8% in the leaves and 53.2% in the roots), while monoterpenoids were present in minor percentages (9.8% in the leaves and 26.2% in the root). The main constituents of the leaves were germacrene D (9.4%), alpha-cadinol (7.4%) and 10-epi-cubenol (6.2%), while the most abundant compounds in the root essential oil were the sesquiterpenes beta-caryophyllene (19.7%) and isoborneol (6.6%). The analysis by HS-SPME of the roots, leaves, fruits and seeds were also reported for the first time. Different volatile profiles were detected.     

Identification of bioactive compounds in the leaves and stems of Aegopodium podagraria by various analytical techniques

The composition of essential oils of the leaves and stems of the Aegopodium podagraria growing wild in Estonia was determined using gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 69 compounds representing over 95% of the total oil were identified. The oil from the stems of A. podagraria was rich in monoterpenes (92.0%). In the leaves oil mainly monoterpenes (43.8%) and sesquiterpenes (29.8%) were identified. The total and extractable content of six mineral elements and two trace elements of the leaves and stems of A. podagraria were determined by atomic absorption spectroscopy (AAS). Capillary electrophoresis (CE) was employed in the fingerprint analysis of A. podagraria extracts.     

Phenolic Composition and Biological Properties of Wild and Commercial Dog Rose Fruits and Leaves

Rosa canina L. (dog rose) is a rich source of phenolic compounds that offer great hope for the prevention of chronic human diseases. Herein, wild and commercial samples of dog rose were chemically characterized with respect to their phenolic composition by liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI/MS). Furthermore, in vitro antioxidant properties and antibacterial activity of dog rose fruits and leaves hydromethanolic extracts and infusions were also evaluated. The results revealed that wild and commercial fruits of dog rose are similar in terms of l(+)-ascorbic acid, total phenolics (TPC), total flavonoids (TFC) and total phenolic acids (TPAC) content, individual phenolic constituents and antioxidant activity. Moreover, the fruits had lower levels of phenolic compounds and also revealed lower biological activity than the leaves. On the other hands, the highest content of TPC, TFC, TPAC, individual phenolic constituents, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity and FRAP (ferric reducing antioxidant power) were found in the leaf’s infusions. They were also the only ones to show antibacterial activity. Overall, these finding confirmed usefulness of R. canina L. leaves and fruits as a rich source of bioactive phenolic compounds with potential use in food, pharmaceutical, and cosmetic industries.