乌奴龙胆中五个新的环烯醚萜甙

从藏药乌奴龙胆（ＧｅｎｔｉａｎａｕｒｎｕｌａＳｍｉｔｈ）（龙胆科）的全草中分离到５个新的环烯醚萜甙,命名为乌奴龙胆甙（ｇｅｎｔｉｏｕｍｏｓｉｄｅ）Ａ－Ｅ;它们的结构主要通过光谱分析得以确定。其中,乌奴龙胆Ａ－Ｃ是二聚环烯醚萜甙,而乌奴龙胆甙Ｄ和Ｅ为马钱素型的环烯醚萜甙,所有这些化合物的分子中都具有一个２,３－二羟基苯甲酰基或其衍生物的取代基。     

坚龙胆中的一个新裂环烯醚萜甙

从坚龙胆（Gentiana rigescens）的根中分离得到1个新的裂环烯醚萜甙,命名为坚龙胆甙A（1）,以及8个已知化合物：龙胆苦甙（2）,6＇-O-β-D-吡喃葡萄糖基-龙胆苦甙（3）,马钱子酸（4）,6＇-O-β-D-吡喃葡萄糖基．马钱子酸（5）,獐牙菜甙（6）,2＇-（邻,间-二羟基苯甲酰基）．獐牙菜甙（7）,獐牙菜苦甙（8）,四乙酰开联番木鳖甙（9）。它们的化学结构通过现代波谱解析得以鉴定。化合物3,5和9为首次从坚龙胆中分离得到。     

翅萼龙胆中的两个寡聚裂环烯醚萜甙

从翅萼龙胆的全株中分离得到两个新的寡聚裂环烯醚萜甙：翅萼龙胆甙Ｉａ和Ｉｂ,其结构通过光谱分析推定。     

不同生长季节下藏药麻花秦艽活性成分含量研究

采用高效液相色谱法测定了野生与栽培藏药麻花秦艽（Gentiana straminea）根中龙胆苦苷、落干酸、獐牙菜苦苷和獐牙菜苷四种环烯醚萜苷类化学成分的含量及其在不同生长季节的变化趋势。结果表明,4种环烯醚萜苷类成分的含量随植物的生长季节而波动,其活性成分含量在野生种与栽培种之间发生了一定的差异。但是,栽培根中的龙胆苦甙已达到药典的标准,可供药用。     

秦艽中的环烯醚萜甙成分

秦艽为著名传统中药。中青海西宁产秦艽的甲醇提取物的水溶性部分分离到１个新裂环烯醚萜甙,命名为秦艽甙Ａ,２个已知的环烯醚萜甙即龙胆苦甙和哈马甙以及２个甾醇甙,胡萝卜甙和β－谷甾醇－３－Ｏ－龙胆糖甙。这些化合物的结构通过红外光谱、紫外光谱、核磁共振波谱（包括－维氢醇－３－Ｏ－龙胆糖甙。这些化合牧的结构通过红外光谱、紫外光谱、核磁共振波谱（包括一维氢谱、碳谱、氢－氢相关谱、碳－氢相关谱、远程碳－氢相关谱     

HPLC法测定山茱萸环烯醚萜苷中莫诺苷的含量

使用HPLC测定山茱萸环烯醚萜苷中莫诺苷的含量。色谱柱为C18柱,流动相为甲醇-水（30：70）,流速0．8mL／min,检测波长240nm。本方法简单、灵敏、可靠。线性范围内莫诺苷的标准曲线呈良好的线性关系,平均加样回收率为98．0％,RSD为2．5％。     

黑蒴中的单萜甙类化合物

自黑蒴(Melasma arvense[Benth.]H.-M.)根中分离鉴定了羟基-β-紫罗兰酮葡萄醣甙(hydroxy-β-ionone glucosid 1)和一新的环烯醚萜甙—桃叶珊瑚甙元-1-O-β-龙胆双醣甙(aucubigenin-1-O-β-gentiobioside 2)。     

4种秦艽属植物不同器官中4种环烯醚萜苷成分含量的比较分析

利用HPLC法测定了秦艽(Gentiana macrophylla Pall.)、粗茎秦艽(G.crassicaulis Duthie ex Burk.)、麻花秦艽(G.straminea Maxim.)和小秦艽(G.dahurica Fisch.)根、茎、叶和花中4种环烯醚萜苷成分(包括马钱苷酸、獐牙菜苦苷、龙胆苦苷和獐牙菜苷)的含量,并对来源于不同产地秦艽和小秦艽不同器官4种环烯醚萜苷成分的含量进行了比较。结果显示:4种秦艽属植物不同器官4种环烯醚萜苷成分含量差异明显,来源于3个产地(陕西太白、甘肃西河乡和马狭)的秦艽和2个产地(青海互助和陕西麟游)的小秦艽不同器官中4种环烯醚萜苷含量也均具有明显差异。4种秦艽属植物根、茎、叶和花中龙胆苦苷和马钱苷酸总量分别为质量分数5.996%～10.869%、0.310%～4.065%、0.235%～4.138%和0.545%～5.591%;根中獐牙菜苦苷和獐牙菜苷的质量分数分别为0.516%～0.953%和0.042%～0.210%,茎中分别为0.173%～0.383%和0.031%～1.700%,叶中分别为0.068%～0.684%和0.020%～3.208%,花中分别为0.460%～0.832%和0.138%～3.827%。粗茎秦艽各器官龙胆苦苷和马钱苷酸总量均最高,小秦艽各器官龙胆苦苷和马钱苷酸总量均最低,总体上,秦艽和粗茎秦艽中龙胆苦苷和马钱苷酸总量高于小秦艽和麻花秦艽;小秦艽茎、叶和花中獐牙菜苷含量均最高,而秦艽茎和叶及粗茎秦艽花中獐牙菜苷含量均最低。4种秦艽属植物根部龙胆苦苷和马钱苷酸含量均明显高于茎、叶和花,獐牙菜苦苷在根和花中的积累较多,獐牙菜苷在花中的含量均相对最高。产自青海互助的小秦艽茎、叶和花中獐牙菜苷含量均最高,质量分数分别为2.884%、5.215%和7.321%。研究结果表明:4种环烯醚萜苷成分含量不但与植物种类和器官有关,而且与产地和采样时间也有关。     

毛球莸和小叶灰毛莸的化学成分

从毛球莸中分离出4个化合物,经MS、~1H-NMR和~(13)C-NMR等波谱分析方法分别鉴定为刺槐素(Ⅰ),香叶木素(Ⅱ),赪桐甾醇(Ⅲ)和一个环烯醚萜甙——8-acetyl ha-pagide。从小叶灰毛莸中除分离到上述环烯醚萜甙,还另外获得一个环烯醚萜甙ajugoside(Ⅴ)。     

环烯醚萜甙的快速原子轰击质谱和场解吸质谱研究

环烯醚萜甙是植物界分布较广泛的一类配糖体成分,极性较大,用通常的电子轰击质谱测试不能得到分子离子信息,且离子碎片零碎,难以进行结构解析。本文对２５个不同类型的环烯醚萜甙进行正,负离子快速原子轰击质谱和场解吸质谱分析,并讨论这两种质谱新技术在环烯醚萜甙类化合物结构解析中的应用。     

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.