中草药“一口钟”的原植物鉴定及其精油的化学成分

云南,四川等省市售的中草药“一口钟”为蓝桉(Eucalyptus globulus Labill.)的果实.用气相色谱-质谱-计算机联用技术、标准品迭加和毛细管保留指数定性法,对其精油的化学成分进行分析.从分离的65个成分中,鉴定出36个成分,其含量占总组成的93.80％,主要成分是别香树烯(23.37％),1.8-桉叶油素(20.81％)、金合欢醇(9.95％)、α-水芹烯(8.30％)、δ-愈创木烯(5.95％)、δ-蒎烯(4.09％)、β-水芹烯(3.43％)、α-愈创木烯(3.15％)等.     

三种桉叶油化学成分研究

通过水蒸汽蒸油试验,发现已贮藏半年多的风干桉叶,仍有较高的含油量。云南省弥勒产的直杆桉(Eucalyptus maidenii)得油率为4.14％,蓝桉(E.globulus)为3.5％,福建省惠安产的窿缘桉(E.exserta)为1.2％,桉叶油生产厂也可以通过贮藏的风干桉叶生产桉叶油。通过气相色谱和质谱分析,从直杆桉叶油中鉴定出44个组份,蓝桉叶油中鉴定出35个组份,窿缘桉叶油中鉴定出26个组份。三种桉叶油单萜部分的组份基本一致,只是相对含量各有不同。桉油素含量,以直杆桉最高为68.02％,其次是蓝桉为67.54％,窿缘桉最低为34.33％。直杆桉、蓝桉可以怍材、油两用树种,窿缘桉不宜作油用树种。     

毛桂和少花桂叶精油的化学成分

湖北省鄂西自治州产毛桂和少花桂叶精油,分别使用Finnigan-4510型毛细管气相色谱/质谱/电子计算机联用(GC/MS/DS)方法进行了化学成分分析。从毛桂叶精油中共检出61个成分,鉴定了其中21个化合物,占精油总量的76.39%,主要成分为1,8-桉叶油素(37.02%)和乙酸龙脑酯(16.24%)。从少花桂叶精油中共检出60余个成分,鉴定了其中33个成分,占全精油的77.85%,含量较高的有α-蒎烯(9.09%)、1,8-桉叶油素(8.27%)、香叶醇(6.03%),香叶醛(5.90%),乙酸香叶酯(4.94%)和黄樟油素(4.43%)等。     

不同生长年限巨尾桉叶挥发性成分GC-MS分析

为了分析不同年限巨尾桉叶挥发油的化学成分及生长年限对化学成分组成的影响,采用水蒸气蒸馏法,分别提取2006～2010年种植的巨尾桉叶片中的挥发性成分,并用气相色谱质谱联用技术分析鉴定其化学成分。结果表明:不同生长年限的巨尾桉叶片挥发油产量在0.55%～1.35%之间,随生长年限的增加而升高。利用GC-MS共鉴定出63个化合物,占总挥发油的93.00%～97.07%。其中相对含量较高的物质为:1,8-桉叶油素(55.72%～63.47%)、α-松油醇(9.78%～14.15%)、乙酸松油酯(4.96%～7.06%)、α-蒎烯(0.99%～4.31%)、龙脑(2.40%～4.89%)。由于生长年限的不同,挥发油中物质的组成及相对含量均存在差异。     

茶树挥发油化学成分的研究

采用毛细管气相色谱-质谱(CGC-MS)联用技术对茶树挥发油的化学成分进行研究,经毛细管气相色谱分离出47个峰,共确认了其中39种成分,占总油量的97％。其主要成分是4-甲基-1-(1-甲乙基)-3-环己烯-1-醇、1-甲基-4-(1-甲乙基)-1,4-环己烯、桉叶油素、( )-4-蒈烯等。     

芳香樟精油毛细管色谱分析

采用弹性石英毛细管柱色谱法测定芳香樟精油中芳樟醇和桉叶油素含量,结果表明：采用４０ｍ石英毛细管柱,程序升温方式提升柱温。方法回收率平均达９４．２％以上,变异系数为３．２１％以下,并认为该法是较好的测试方法。     

野生香料植物石荠Zhu资源的开发利用研究

石荠Zhu,广布于长江以南各省,全草含挥发油,含量为0.40％－1.20％。对不同产地的全草挥发油的化学成分进行对比分析,其挥发油主要成分为：香荆芥酚(carvacrol)、1,8－桉叶油素（1,8－cineole）、百里香酚（thymol)、β-(caryophyllene)、侧柏酮(thujone等）,不同产地,其挥发油的化学成分存在遗传相似性,又有一定的差异。植物资源在香精香料、医药、化妆品等行业具有广大开发利用的价值。     

赤桉单萜合成酶基因的分子克隆与生物信息学分析

桉叶油是一种从桉树叶分泌出来的挥发性芳香精油,主要含有1,8-桉叶油素和萜类化合物等物质,具有重要的药用活性.为深入了解桉树萜类化合物的生物合成途径和分子调控机理,该研究通过扩增从赤桉嫩叶中获得了1条单萜合成酶基因组序列的保守区段后,利用 RACE 技术得到此基因的 cDNA 序列,将其命名为 EC-MS 基因,并进一步获得此基因的 DNA 序列.通过生物信息学分析发现,EC-MS 基因的 DNA 序列长为3763 bp,含有7个外显子和6个内含子,cDNA 长度为1734 bp,编码577个氨基酸,并且具有 MS 蛋白特有的保守序列和相关特征,与蓝桉和白千层等植物的 MS 蛋白具有较高的相似性.EC-MS 的等电点为5．615,存在1个跨膜区,Arg21为信号肽剪切位点,同时,EC-MS 的立体结构以α-螺旋为主,几个底物结合点经过空间折叠后形成了“口袋型”底物结合区.     

柠檬醛和桉叶油素的新资源植物

对湖北川桂叶油等四个样品的化学成分,使用毛细管气相色谱/质谱/计算机联用系统进行分析。结果表明,其中三个样品富含柠檬醛:长阳产川桂叶油(含77.99%)、咸丰产川桂叶油(含86.47%)和湖北樟叶油(含95.01%)。另外,樟树油樟型的叶油中,主要成分为1.8-桉叶油素,含量高达65.76%。这几种樟属植物是湖北的常见树种,资源丰富,鲜叶出油率较高,可供开发利用。     

姜樟叶油的化学成份研究

姜樟鲜叶经水蒸汽蒸馏得到一种淡黄色的精油,得率为0.5-0.8％。我们应用气相色谱、红外光谱、气相色谱/质谱/计算机联用以及测定衍生物熔点等方法,对该精油进行成份分析、鉴定。共鉴定出α-,β-柠檬醛,香叶醇,柠檬烯,1,8-桉叶油素,芳樟醇,氧化芳樟醇,樟脑,龙脑,石竹烯等47个已知化合物,其中α-,β-柠檬醛含量高达64.11％。它们是香料工业和医药工业上的重要原料。     

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

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.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).