利用GC-MS技术分析油橄榄叶挥发油化学成分

本文采用同时蒸馏萃取法(SDE)提取油橄榄叶挥发油化学成分,利用气相色谱-质谱(GC-MS)联用方法分析并用峰面积归一化法得出各化学成分在挥发油中的百分含量。结果从油橄榄叶挥发油中分离出62各色谱峰,鉴定出56个化合物,占挥发性组分总量的95.6%。其中主要成分为α-芹子烯(13.13%)、β-芹子烯(10.15%)、β-石竹烯(14.29%)、橙花叔醇(6.72%)、α-石竹烯(6.60%)、3-己烯-1-醇(5.03%)、苯乙醛(5.61%)等。     

火麻仁挥发油的化学成分研究

本文采用水蒸气蒸馏法提取传统中药火麻仁中的挥发油,用GC毛细管柱进行分析,面积归一化法测定其相对含量,并用GC-MS鉴定其化学成分.共检出90个色谱峰,鉴定其中62个化合物,占挥发油总量的89 25%.鉴定的成分包括44种烃类化合物、7种芳香族化合物和11种脂肪族化合物及其衍生物.烃类化合物中以萜类为主,占挥发油总量的32.01%,相对含量较高的单萜及其衍生物包括β-芳樟醇(1.66%)、β-顺式-罗勒烯(1.30%)、樟脑(0.93%)、冰片和薄荷醇(0.44%);相对含量较高的倍半萜及其衍生物包括大牦牛儿烯 D(8.20%)、α-芹子烯(5.23%)、β-丁香烯(3.65%)、氧化石竹烯(2.22%)、δ-愈创木烯(1.55%)和α-丁香烯(1.19%).     

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%...     

下田菊挥发油化学成分的研究

利用水蒸汽蒸馏法、两相溶剂萃取法提取下田菊(Adenostemma lavenia(L.)O.Ktze.)地上部分的挥发油,提取10h的挥发油得率为0.990%。采用毛细管气相色谱-质谱联用(GC-MS)技术结合计算机检索对该挥发油的化学成分进行了分析和鉴定,采用色谱峰面积归一化法计算了各成分的相对含量。从挥发油中共分离出36个峰,鉴定了其中的35种成分,占总量的99.56%,其中α-荜澄茄油烯(32.62%)、石竹烯(24.97%)和γ-榄香烯(5.53%)为主要成分,此外α-石竹烯(3.97%)、α-恰米烯(3.57%)、双环[4,3,0]-7-亚甲基-2,4,4-三甲基-2-乙烯基-壬烷(3.41%)、γ-萜品烯(3.07%)、d-柠檬烯(2.57%)、α-蒎烯(2.49%)及2-蒈烯(2.28%)的含量也较高。     

醉香含笑叶挥发油化学成分

应用气相色谱一质谱联用技术对水蒸汽蒸馏法提取的醉香含笑(Michelia maccturei Dandy)叶挥发油的化学成分进行分析.共检出61个峰,鉴定丫其中45个化合物,占挥发油总量的91.41%.其中石竹烯(18.74%)、β-榄香烯(14.56%)、榄香醇(13.14%)、.γ-榄香烯(9.18%)、α-桉叶醇(7.22%)、α-石竹烯(5.20%)和.γ-桉叶醇(4.90%)为主要成分.     

乌榄叶挥发油化学成分分析

采用气相色谱-质谱联用(GC-MS)方法首次对乌榄叶挥发油成分进行了测试分析,并应用色谱峰面积归一化法计算各成分的相对含量。分离出19个峰,确认了19种化合物,所鉴定的组分占挥发油总量的100%,主要成分是石竹烯(33.47)、α-蒎烯(18.03%)、d-柠檬烯(16.82%)、α-侧柏烯(11.74%)和α-水芹烯(6.51%)。     

鸭儿芹根、茎、叶挥发油的化学成分

采用水蒸气蒸溜法提取其根、茎、叶中的挥发油,利用GC-MS联用仪对其化学成分进行分析,以归一化法计算各个化学成分的相对含量.鸭儿芹根挥发油中共分离出11个峰,鉴定出11种化合物,占总离子峰的98.61％,主要成分为α-芹子烯、γ-芹子烯等;茎中共分离出25个峰,鉴定出25种化合物,占总离子峰的100.00％,主要成分为...     

假鹰爪鲜花挥发油成分研究

分别利用顶空固相微萃取法(Head Space-Solid phase microextraction,HS-SPME)和水蒸汽蒸馏法提取了黄色假鹰爪鲜花的挥发油成分,用气-质联用技术(GC-MS)对挥发油成分进行了分析,对比了两种提取方法得到的黄色假鹰爪鲜花挥发油成分的异同.顶空固相微萃取法得到的黄色假鹰爪鲜花挥发油成分中芳樟醇(46.19%),香茅醇(3.97%),反-香叶醇(4.21%),香叶酸甲酯(26.64%),(2Z)-3,7-二甲基-2,6-辛二烯酸乙酯(3.40%)五种物质的含量较高,其中三种醇类物质占总挥发油的54.37%;两种酯类物质占总挥发油的30.04%.水蒸汽蒸馏法得到的黄色假鹰爪鲜花挥发油成分中β-石竹烯(31.76%),α-石竹烯(8.63%),大根香叶烯D(4.65%),匙叶桉油烯醇(4.44%),α-石竹烯氧化物(12.98%)五种物质的含量较高.另外,通过对比发现不同生长期假鹰爪鲜花虽然香味差别较大,但是由水蒸汽蒸馏油得到的挥发油成分的种类及含量基本相同.     

野花椒果皮挥发性成分的研究

采用水蒸气蒸馏法提取野花椒果皮挥发油,出油率为0．603％。运用气相色谱-质谱联用技术分析,从野花椒果皮挥发油中分离出150个色谱峰,鉴定了107个化合物,占总量的92．96％,主要有1,8-桉油素（17．91％）、柠檬烯（12．66％）β-榄香烯（9．81％）、α-萜品醇（7．61％）β-芹子烯（4．81％）、β-芹子烯（3．79％）、α-石竹烯（3．71％）等。     

中国特有植物银杉叶精油成分的研究

本文用气相色谱-质谱-计算机联用仪,分离了银杉(Cathaya argyrophylla)叶精油主要成分26个,鉴定了19个化合物,并测定了含量。其中主要成分有α-蒎烯、β-蒎烯、α-龙脑烯醛、反式-松香芹醇、桃金娘烯醛、马鞭草烯酮和石竹烯氧化物等。     

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

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.