滇南红厚壳种子油的脂肪酸成分

应用GC-MS联用技术对云南省西双版纳产的滇南红厚壳（Calophyllumpolyanthum）种子油的脂肪酸成分进行分析.检出12种脂肪酸成分,占总量的99.39%,主要是亚油酸（38.75%）,棕榈酸（22.42%）,油酸（22.11%）和硬脂酸（9.81%）.     

朝鲜蓟叶中一个新的倍半萜内酯

从朝鲜蓟（Cynarascolyrnus）叶中分离得到2个倍半萜内酯,其中一个是新化合物,通过波谱学方法确定其结构为3β,8α,11α,13-四羟基-10（14）-愈创木烯-1α,4β,5α,6β氢-6α,12-内酯（1）。     

海南红厚壳花香气成分采集和TCT-GC-MS分析

用鲜花循环式动态顶空技术采集红厚壳鲜花的香气成分,TCT-GC-MS联用技术分析鉴定。4-羟基-2-丁酮,双烯酮,1、2-环氧-2-甲基丁烷,1、2-环氧-3-甲基丁烷,2-乙基戊烷,3-己醇,甲基环戊烷,2-丁醇等24个成分被检测出,占总离子流出峰面积的90.28%。并对结果进行了分析讨论。     

朝鲜蓟叶中的酚性糖苷化合物

从朝鲜蓟（Cynara scolymus）叶中分离得到2个酚性糖苷化合物,其中一个是新化合物,通过波谱学方法确定其结构为2-甲氧基-4-（2,3-二羟基-丙酰基）-苯基-1—O-（6′-O-没食子酰基）-β-D-吡喃葡萄糖苷（1）。     

银桦酸和银桦内酯的生源探讨

新的植物产物银桦内酯（I）（Grevillone)（即 6-羟基香豆素,－Hydroxycou－marin）与其结构相应的开环酸——银桦酸（Ⅱ）（Grevillic acid）（即2,5-二羟基-反式-桂皮酸,2,5－Dihydroxy－trans－cinnamic acid）共存于山龙眼科（Proteaceae）的银桦（Grevillea robusta A．Cunn．）叶,提示它们在生物化学上是密切相关的。并且,无论是银桦内酯或银桦酸,在植物界里迄今仅发现于银桦[1]中。桂皮酸（III）（Cinnamic acid）的羟基化衍生物及其结构相应的内酯——香豆素类化合物,都是高等植物的典型代谢产物[4]。在双子叶植物里,苯基丙氨酸（Phenylalanine）是它们的共同前体[4,5]。最常见的羟基桂皮酸类是P-香豆酸（IV）（P-Coumaric acid）,咖啡酸（V）（Caffeic acid）,阿魏酸（Ⅵ）（Ferulic acid）和芥子酸（Ⅶ）Sinapic acid）。它们之中的一个或几个,以酯或甙的结合形式存在于每种高等植物[6]中,并且在代谢上密切相关[3,4]。这几个酚酸的共同特征是在对位碳上连接着氧原子（羟基）。显然,这与几乎所有天然香豆素类（Coumarins）化合物都在 7位碳（C7）上连接着氧原子[7,8]的特征在结构关系上是一致的。表1列出了在高等植物里最常见的几个羟基桂皮酸[2, 4]和香豆素类化合物[4,7]。邻-羟基桂皮酸类[6]（O－Hydroxycinnamic acids）和间-羟基桂皮酸（m-Hydroxycinnamic acid）在植物界里较罕见。     

四方蒿的化学成分

从唇形科植物四方蒿（Elsholtzia blanda (Benth.)Benth.)中分离得到9个化合物,用光谱分析、化学方法及与已知化合物对照,分别鉴定为：5,6－二氢－6－苯乙类吡喃－2酮（1）、木栓桐（2）、4－羟基－3－甲氧基苯乙烯（3）、5,2′－二甲氧基－6,7－二氧亚甲基双氢黄酮（4）、5－羟基07－甲氧基－6－O[α－L－鼠李糖（1→2）－β－D－岩藻糖]黄桐甙（5）,5,5′－二羟基－7－乙酰氧基6,8,3″,3″－四甲基吡喃（3′,4′）黄酮（6）、5,5′－二羟基－5－（α－甲基）丁酰氧基－6,8,3″,3″－四甲基吡喃（3′,4′）黄酮（7）、5,5′－二羟基－6,7－二氧亚甲基－8,3″,3″－三甲基吡喃（3′,4′）黄酮（8）和丁香酸葡萄糖甙（9）。其中,6、7、8为新化合物,分别命名为四方蒿素Ⅰ、Ⅱ和Ⅲ。     

三叶崖爬藤中的新黄酮碳甙

从三叶崖爬藤（Tetrastigma hemsleyanum Diels et Gilg)的95%乙醇提取物中分离得到3个黄酮碳甙,经化学方法和光谱分析鉴定为：5,7,4′-三羟基黄酮-6-α-L-吡喃鼠李糖（1-4）-α-L-吡喃阿拉伯糖甙（1）,5,7,4′-三羟基黄酮-8-α-L-吡喃鼠李糖（1-4）-α-L-吡喃阿拉伯糖甙（2）,5,7,4′-三羟基黄酮-6,8-二-C-β-D-吡喃葡萄糖甙（3）,1和2为新化合物,分别命名为崖爬藤甙和异崖爬藤甙。     

多穗金栗兰中一个新的酚苷

从多穗金粟兰(Chloranthus multistachys)全株的甲醇提取物中分离得到1个新的酚苷,通过波谱技术鉴定其结构为丁香酸-4-O-a-L-鼠李吡喃糖苷(1).同时还首次从该植物中分离得到两个已知倍半萜内酯和一个已知木脂素:1β,4β-二羟基-5a,8β-二氢-7(11)Z-桉叶烯-8,12-内酯(2),lβ,4a-二羟基-5a,8β-二氢-7(11)Z-桉叶烯-8,12-内酯(3),(-)-(7S,8R)-dihydrodehydrodiconifery alcohol(4).     

樱草杜鹃中的黄酮类化合物

从樱草杜鹃（Rhododendron primulaeflorum）地上部分的乙醇提取物中分离得到10个黄酮类化合物,经理化性质及波谱分析,鉴定为杜鹃素（1）、4’,5,7-三羟基-8-甲基黄烷酮（2）、二氢山柰酚（3）、异鼠李素（4）、槲皮素（5）、陆地棉苷（6）、瑞诺苷（7）、（2R,3R）－花旗松素-3—O-α-L-吡喃阿拉伯糖苷（8）、（2R,3S）-花旗松素-3—O-α-L-吡喃阿拉伯糖苷（9）、（2S,3R）－花旗松素－3－O－α－L－吡喃阿拉伯糖苷（10）。所有化合物均为首次从该植物中分得。     

中药金樱子的化学成分

从中药金樱子（Rosa laevigata Michx.）的果实是分离到7个化合物,经理化性质和波谱分析分别确定为β－谷甾醇（1）、胡萝卜甙（2）、乌苏酸（3）、2α,3β,19α,23－四羟基乌苏－12－烯－28酸（4）,2α,3β,19α,23－四羟基乌苏－12－烯－28酸28－O-β-D-吡喃葡萄糖苷（5）,2α,3β,19α,23－三羟基乌苏－12－烯－28酸（6）和4',5,7－三羟黄酮醇－3－O－β-D-（6”－O－（E）－p－羟基苯丙烯酰）吡喃葡萄糖苷（7）,其中化合物4、5、7为首次从金樱子果实中分离得到。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV