小叶女贞果实挥发油的GC-MS分析及其抗氧化活性

首次采用气相色谱-质谱联用(GC-MS)分析小叶女贞果实挥发油化学成分,并以ABTS自由基和亚硝酸钠清除作用评价25%挥发油抗氧化活性。从小叶女贞果实挥发油中共鉴定出67种化合物,占挥发油总量的76.50%,主要成分有大根香叶烯D(8.57%)、顺式-2-反式-6-金合欢醇(6.38%)、α-荜澄茄烯(5.24%)、2-己烯醛(3.80%)、芳樟醇(3.78%)、α-衣兰油烯(3.70%)等。挥发油对ABTS自由基和亚硝酸钠具有明显地清除作用,样品量与清除率间呈量效关系。     

猪殃殃挥发油化学成分的GC-MS分析

利用水蒸气蒸馏法提取猪殃殃挥发油成分,进一步采用气相色谱-质谱(GC/MS)联用方法对其化学成分进行分析,共鉴定了110种主要成分(占挥发油总量的87.38%),主要为十六烷酸(13.88%)、芳樟醇(11.90%)、6,10,14-三甲基-2-十五烷酮(8.79%)、3-乙基-1,4-己二烯(2.37%)、2-戊-呋喃(2.09%)、2-己烯醛(1.90%)、己醛(1.89%)、(Z)-香叶醇(1.84%)和α-松油醇(1.83%)、植醇(1.81%)等。110个化合物均为首次从猪殃殃植物中被发现。     

贵州刺槐花精油的化学成分

刺槐(Robima Pseudoacacia L.)花精油,用 Finn(?)gan-4510色谱/质谱/计算机联用仪分析,共检出43个成分,鉴定了其中38个化合物,占全精油的97.70％。主要成分为已酸乙酯(0.20％),苯甲醇(0.17％),芳樟醇(3.11％)苯乙醇(12.07％),辛酸乙酯(0.13％),香叶醇(2.14％),王内酯(0.86％),特檀香醇(0.21％),橙花叔醇(0.89％)等。     

小果蔷薇净油化学成分的研究

从贵州的小果蔷薇(Rosa cymosa Tratt.)花制备净油。用毛细管色谱/质谱/计算机联用方法进行了化学成分分析,鉴定了34个化合物。占净油的93.75％。主要芳香成分为苯甲醇(46.26％).丁香酚(10.02％),苯乙醇(9.17％),肉桂醛(6.87％),苯丙酸乙酯(4.11％)。芳樟醇(3.76％),苯甲酸乙酯(3.19％),柠檬醛(2.07％)等。该油具有特殊芳香。适用于调配化妆品、食品、饮料等香精,具有增香、定香的作用。     

喜树种子挥发油化学成分的研究

利用常压水蒸气蒸馏法提取喜树种子挥发油,得率０．３５％。并进行ＧＣ／ＭＳ／ＤＳ研究研究,鉴定出占挥发油总组成８３．７４％和５５种成分的化学结构,其主要成分为：反－芳樟醇氧化物、苯乙醇、顺－芳樟醇氧化物、大牦牛儿烯、等。     

迎春挥发性成分HS—SPME—GC—MS分析

采用顶空固相微萃取和气质联用技术(HS-SPME-GC-MS),首次分析了河南产迎春花蕾和花的挥发性成分.花蕾中鉴定了34个成分,花中鉴定了23个成分,有13个共有成分.其中9个共有烷烃以十五烷为转折点,在此转折点以前,随着花蕾开放逐渐增多;在此转折点以后,随着花蕾的开放烷烃逐渐减少.4-亚硝酸基-苯磺酸(4-溴甲基-2-金刚烷基)酯(14.98%)、亚油酸(14.48%)和苯甲醇(3.32%)只存在与花中,苯乙醇在花蕾中含量很少,而在开放的花中含量明显增加,表明4-亚硝酸基-苯磺酸(4-溴甲基-2-金刚烷基)酯、苯甲醇和苯乙醇是迎春花主要香味成分.     

连翘花蕾与花的挥发性成分研究

本文采用顶空固相微萃取和气相色谱质谱联用(HS-SPME-GC-MS)技术比较分析了连翘花蕾和花的挥发性成分。从连翘花蕾和花中共鉴定了83个化合物,其中40个化合物是共有的。连翘花蕾的挥发性成分以烃类(41.04%)为主,而连翘花的挥发性成分以醇、醛和酮类化合物(26.46%)为主;酯类化合物在花蕾中的含量为8.11%,在花中下降到2.12%;而酸类化合物则从3.56%上升到5.18%。结果表明,随着花蕾的开放,酯类成分逐渐被水解为酸。     

樟树叶挥发性成分研究

通过GC/MS方法,对湖南樟树嫩叶、老叶以及枯叶挥发油的成分和抗氧化性能进行了研究,分析鉴定了其中含量占95%以上的31个化合物.结果表明:嫩叶中以Copaene(28.55%)、石竹烯(25.81%)和α-石竹烯(12.69%)为主要成分;老叶挥发油以芳樟醇含量最高(78.30%);枯叶挥发油主含石竹烯(38.64%...     

我国4种红茶的挥发性成分分析

为了解我国4种名优红茶挥发性成分的异同,采用全自动顶空固相微萃取结合气相色谱-质谱分析,对滇红、祁红、正山小种和金骏眉的挥发性成分进行了研究。结果表明,4种红茶中共鉴定出挥发性成分90种,滇红茶中主要是芳樟醇、香叶醇、芳樟醇氧化物、水杨酸甲酯、2-戊基呋喃和橙花叔醇,祁红中主要是十六碳酸、植酮、香叶醇、芳樟醇氧化物、β-紫罗酮、植醇和蒽等,正山小种中主要是植酮、香叶醇、β-紫罗酮、二氢猕猴桃内酯、咖啡因和芳樟醇氧化物,而金骏眉中主要是香叶醇、咖啡因、芳樟醇氧化物、β-紫罗酮、苯乙醇、橙花叔醇和植醇;他们共同成分有苯甲醛、苯乙醛、芳樟醇氧化物、芳樟醇、香叶醇、α-紫罗酮、β-紫罗酮、植醇等。4种红茶在挥发性组成及含量上差异较大,共有成分仅32种;醇类化合物含量均较高,其中滇红茶中醇类化合物含量高达69.08%;而祁红、正山小种和金骏眉中酮类化合物含量较高。不同化合物之间比例和阈值的不同,形成了4种红茶各自独特的香气特征。     

孜然芹种子挥发油化学成分的研究

本文用毛细管气相色谱和 GC/MS 联用技术,从孜然芹(Cuminum cyminum L.)种子挥发油中鉴定出:α-蒎烯、β-蒎烯、莰烯、月桂烯、γ-松油烯、对-聚伞花素、异松油烯、芳樟醇、胡薄荷酮、枯茗醛和桃金娘醛11个组分。又用硅胶柱层析,并经 IR、MS 和 NMR 等波谱法解析,确证了已知化合物的结构为     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.