串钱柳挥发油化学成分及其抗细菌活性

【目的】阐明串钱柳叶片和果实挥发油的化学组成及其抗细菌活性,以期为串钱柳的综合开发和利用奠定基础。【方法】采用水蒸气蒸馏法分别提取串钱柳叶片和果实中的挥发油,通过气相色谱-质谱联用(GC-MS)对提取得到的挥发油进行化学成分分析,并通过滤纸片扩散法测定了挥发油对7种供试细菌的抑制活性。【结果】串钱柳叶片和果实中挥发油的得率分别为0.87% 和0.16%,从串钱柳叶片和果实中分别鉴定出14和17个成分,分别占二者挥发油总量的93.34%和90.29%。叶片挥发油中的主要成分为桉叶油醇(52.89%)、(1R)-(+)-α-蒎烯(17.28%)和α-松油醇(10.70%); 而果实挥发油的主要成分为桉叶油醇(38.53%)、(1R)-(+)-α-蒎烯(29.90%)和2-莰烯(8.02%); 串钱柳叶片和果实挥发油对7种供试细菌均表现出一定的抑制作用,其中果实挥发油对根癌农杆菌的抑制活性最强,抑菌圈直径为(25.2±2.8)mm,而叶片挥发油对桉树青枯病菌的抑制活性最强,抑菌圈直径为(22.3±1.5)mm。【结论】串钱柳叶片中挥发油的含量高于其果实,叶片和果实挥发油的主要成分均为桉叶油醇和(1R)-(+)-α-蒎烯,果实挥发油的抑菌活性要强于叶片挥发油。     

佛手叶挥发油的成分分析及生物活性研究

分析了佛手叶挥发油的成分,检测了其生物活性.采用水蒸气蒸馏法提取佛手叶挥发油,气相色谱-质谱联用技术(GC-MS)检测了佛手叶挥发油的成分,比浊法检测了其抑菌活性,噻唑蓝法检测了其细胞活力.佛手叶挥发油含有40种成分,以d-柠檬烯、γ-松油烯、对伞花烃、α-蒎烯、β-蒎烯为主要成分,其中d-柠檬烯和γ-松油烯的含量分别占50.53%和24.05%.佛手叶挥发油对草绿色链球菌、肺炎克雷伯菌、摩氏摩根菌、大肠杆菌、表皮葡萄球菌和溶血性链球菌等均有抑制作用,其半抑制浓度(IC50)分别为1.1,2.1,6.8,7.2,13.7和19.3 mg/mL;佛手叶挥发油对Hep3B,HUVEC,Huh7,SP2/0,A549和PANC-28等癌细胞具有抑制作用.     

乌蕨挥发油成分分析及其抗菌活性

 对植物乌蕨(Stenoloma chusanum(L)Ching)中的挥发油成分进行定性和定量分析并开展其抗菌试验.采用水蒸汽蒸馏提取挥发油成分,用气相色谱-质谱(GC/MS)联用仪进行成分分析;采用纸片法扩散法开展其抑菌试验.从乌蕨挥发油中分析出36种成分,鉴定了其中的24种,其主要成分是芳樟醇(24.76%),松油醇(7.24%)和香叶醇(6.06%).抗菌活性研究显示,乌蕨挥发油对枯草芽孢杆菌、伤寒沙门氏菌有明显的抑制作用,对铜绿假单胞菌大肠埃希氏菌、金黄色葡萄球菌和藤黄微球菌抑制活性很低或没有活性.乌蕨挥发油成分检出率为72.0%,其中主要成分为单萜类化合物;挥发油具有一定的抗菌活性.     

苏木挥发油成分的GC-MS分析

目的:分析苏木挥发油化学成分,为其开发利用和质量评价提供科学依据.方法:采用水蒸气蒸馏法提取苏木挥发油,采用GC-MS法鉴定挥发油化学成分.结果:检出38个色谱峰,鉴定出16个化合物,占挥发油总量的42.01%.其中(Z,Z)-9,12-十八碳二烯酸(10.53%),邻苯二甲酸二丁酯(5.02%),(E,E)-2,4-癸二烯醛(4.36%),邻苯二甲酸异壬酯(3.01%),桉油烯醇(2.27%),1,2,3,4-四氢化-5-甲基-1-3-异丙氧基萘(2.08%)是主要成分,占挥发油总量的27.27%.结论:苏木挥发油进一步研究及开发利用提供科学依据.     

云木香挥发油化学成分的研究

目的:对云木香挥发油进行化学成分的研究,为云木香的进一步开发和利用提供科学依据.方法:采用水蒸气蒸馏法从云木香中提取挥发油,用气相色谱-质谱法对化学成分进行分析,以归一化法计算各个化学成分的相对含量.结果:共分离出140个峰,鉴定了其中56个化学成分,占挥发油总油量的83.29%.结论:云木香挥发油中的主要成分为(Z,Z,Z)-9,12,15-十八碳三烯-1-醇(20.07%)、1,2,3,3a,4,5,6,7-八氢-1,4-二甲基-7-(1-甲基乙烯基)-[1R-(1α,3aβ,4α,7β)]-薁(10.04%)、石竹烯(6.69%)、3a,4,6a,7,8,9,9a,9b-八氢-6-甲基-3,9-二亚甲基-[3aS-(3aα,6aα,9aα,9bβ)]-奥[4,5-b]呋喃-2(3H)-酮(6.37%).     

柏树果壳挥发油成分及其抗菌活性研究

该实验以柏树果壳(干壳)为原料,利用不同方法提取挥发油,并用气相色谱-质谱联用技术进行分析鉴定,测得挥发油含量为2.5%～3.0%,鉴定出19～26种化学组分,主要成分为(1R)-2,6,6-三甲基-二环[3.1.1]庚-2-烯、β-水芹烯、3-蒈烯,测得挥发油对5种供试菌具有较好的抑菌性,尤其对化脓性链球菌和金黄色葡萄球菌高度敏感.柏树果壳(干壳)挥发油含有多种抑菌活性的成分,为柏树果壳的进一步开发提供依据.     

巨尾桉叶挥发性成分的提取及成分分析

采用水蒸气蒸馏法从巨尾桉叶中提取挥发油中的油相成分,用乙醚作为溶剂从蒸馏残液中萃取挥发油的水溶性物质,利用气相色谱-质谱(GC-MS)联用法分析二者的化学成分并进行比较.巨尾桉叶挥发油油相成分的得油率为0.67%(W/W,以干重计),确认了32种成分,占油相部分总量的97.65%.主要成分为1,8-桉叶油素(39.70%),其后依次是α-蒎烯(22.03%)、α-松油醇(11.76%)、龙脑(5.78%)和乙酸松油酯(4.60%)等;水溶性成分的得油率为0.87%(W/W,以干重计),确认了32种成分,占水溶性部分总量的87.14%,异戊酸(15.03%)、1,8-桉叶油素(10.75%)、α-松油醇(9.85%)是水溶部分的主要成分.     

红千层挥发油的化学成分分析

用气相色谱(GC)-质谱(MS)-计算机分析技术对红千层挥发油进行成分分析。采用水蒸气蒸馏法从红千层中提取挥发油,利用气相色谱-质谱联用技术分离鉴定,采用GC峰面积归一化法确定其相对含量。挥发油平均得油率为0.2%;分离出60多个组分;鉴定了其中的40多种成分,其中1,8-桉叶素占53.46%、松油醇-4占2.66%、α-蒎烯占12.07%、α-松油醇占12.72%、γ-松油烯占1.39%、香叶醇占1.18%等;占色谱总馏出峰面积的90%以上。结果表明:红千层挥发油主要化学成分为蒎烯、桉叶素、松油醇等化合物。     

4种樟科园林树种挥发性物质杀菌能力测定及有效成分分析

以香樟、白楠、琼楠、润楠等4种樟科植物为试材,对其挥发性物质的杀菌能力及叶片精油的含量和成分进行测定和分析,结果表明:1d内平均抑菌率从大到小依次为白楠(68.99%),香樟(57.36%),润楠(43.44%),琼楠(40.54%);各树种的叶片精油出油率以香樟的出油率(2.47%)为最高,远高于琼楠(0.19%),润楠(0.16%)及白楠(0.14%);精油主要组成成分各有不同,香樟主要含有反式-橙花叔醇(26.77%),芳樟醇(10.35%),白楠主要含有萘的化合物(26.58%),α-蒎烯(8.46%),琼楠主要含有α-蒎烯(13.88%),乙酸冰片酯(6.91%),润楠主要含有癸醛(33.66%);4种精油的抑菌活性测定表明,其抑菌圈均在15mm以上.     

玫瑰茄挥发油的GC-MS分析及其抗菌活性研究

目的:研究玫瑰茄挥发油成分及其抑菌活性.方法:运用常规水蒸气蒸馏法提取玫瑰茄挥发油,采用气相色谱-质谱联用(GC-MS)的方法分析、鉴定其化学成份,并采用琼脂稀释法对其挥发油进行抗茵活性测试.结果:通过GC-Ms共鉴定出48个化学成分,且抑茵实验表明8种菌株为敏感菌株.结论:该研究为玫瑰茄的进一步应用与开发提供了科学依据.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the