乐东拟单性木兰花部挥发油的化学成分及其抑菌活性

采用GS－MS技术分析了乐东拟单性木兰花部挥发油的化学组成,共鉴定了57种成分的化学结构与相对含量,占总含量地85．59％。其中,β－ 蒎烯（12．85％）、D－柠檬烯（7．78％）、石竹烯（4．89％）、十氢－4a－甲基－1－亚甲基－7－（1－甲基乙烯基）－萘（4．70％）为主要成分。此外,醇类中α-杜松醇（3．61％）、1氢－[1,3]环戊并[1,2]环戊并[1,2]环丙并－苯（3．52％）、倍半萜含氧衍生物石竹烯氧化物（3．33％）和α－蒎烯（3．22％）也占有较大比例。体外对4种供试病原菌的抑菌实验表明,该挥发油对大肠杆菌和伤寒杆菌有一定的抑制或杀灭能力。     

多花含笑叶的挥发油成分研究

运用气相色谱－质谱－计算机联用技术,结合标准谱库,对昆明产多花含笑叶的挥发油成分进行了研究,分离鉴定了42个化合物,其中单萜16个,倍半萜21个,分别占精油总含量的21＝21％和49．08％,主要成分为γ－木罗烯（12．04％）,十六碳三烯酸甲酸（7．45％）,兰桉醇（7．38％）,1,8－桉叶素（5．76％）,α－愈创木烯（5．64％）,香桧烯（4．26％）,十六碳二烯酸甲酯（4．26％）,β－槛香烯（3．76％）,β－蒎烯（3．20％）等。     

华北落叶松枝叶挥发性成分

利用水蒸气蒸馏法提取华北落叶松枝叶的挥发油,进一步采用气相色谱-质谱联用方法对其化学成分进行分析,共分离鉴定出79种化学成分,主要有大根香叶烯（11．35％）、1-异丙基4,7．二甲基-1,2,4a,5,8,8a-六氢萘酚（6．53％）、石竹烯（5．84％）、长叶松节烷（5．23％）、7-甲基4-亚甲基-1-（1-甲基乙基）-1,2,3,4,4a,5,6,8a-八氢萘（5．21％）、（E）-3,7,11-三甲基-1,6,10-十二烷三烯-3-醇（5．17％）、．tau．-muurolol（4．55％）、α-杜松醇（4．31％）、α-石竹烯（4．22％）等,其中萜烯类及其含氧衍生物占较大比例。     

拳卷地钱挥发油成分分析

采用水蒸气蒸馏法从拳卷地钱中提取挥发油成分,并用气相色谱-质谱法(GC—MS)联机分析,共分 离出25个峰,鉴定了其中10种物质,占挥发油总组分的40．0％。在所分离的化合物中,碳氢化合物5种,烃 类含氧衍生物5种。主要成分为norpinane和hedycaryol,另外8种含量均在1％以上。在气相色谱分析中, 选择了合适的色谱条件,采用非极性的HP5柱,对地钱挥发油中的弱极性和非极性成分有较好的分离效果。     

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。     

三七叶挥发油的化学成分分析

采用自制的同时蒸馏萃取装置提取文山三七叶的挥发油成分,然后用GC-MS法分析并鉴定了各组成及质量分数。挥发油中共鉴定出69个成分,占总峰面积的73．09。主要挥发性成分及面积归一化法测得含量为棕榈酸（27．36％）、亚油酸（10．68％）、亚麻醇（8．60％）、2,6-二叔丁基对甲基苯酚（4．67％）、1,3-环辛二烯（3．90％）、5．十八炔（2．31％）、植物醇（1．92％）、六氢化法尼基丙酮（1．39％）、斯巴醇（1．35％）等。     

巴戟天挥发性成分研究

目的：研究巴戟天中的挥发性成分。方法：利用水蒸气蒸馏法提取巴戟天（Radix morindae offtcinalis）挥发油,用GC—MS进行测定,结合计算机检索技术对分离的化合物进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果：鉴定出34个化学成分,其中相对百分含量大于2％的分别确定为L-龙脑（Bomeol L）29．28％,α-姜烯（Alpha—Zingiberene）4．88％,2-甲基-6-对甲基苯基-2-庚烯（Ar-Cureumene）4．49％,1-己醇（1-Hexanol）3．40％,β-倍半水芹烯（beta—sesquiphellandrene）3．34％,2-戊基呋喃（2-Amylfuran）3．32％,正壬醛（n—nonanal）2．17％,樟脑（L—camphor）2．07％,β-没药烯（bete—Bisabolene）2．06％。结论：34个挥发性成分均为首次从该植物中得到。     

石荠苧精油的GC-MS分析及其抑菌活性的研究

利用水蒸汽蒸馏法提取石荠芋（Mosla scabra（Thunb．）C．Y．Wu et H．W．Li]精油,得油率为1．2％。采用GC—MS方法分析了该挥发油的化学组成,检测到125个峰,共鉴定出其中67个化学成分并测定其相对含量。占总含量的95．25％。其中,（R）侧柏酮（26．11％）、（M）侧柏酮（13．66％）、石竹烯（8．89％）、桉叶油素（7．99％）、（R）-α-石竹烯（6．45％）、芹菜脑（5．43％）和β-荜澄茄油烯（4．51％）为主要成分。体外抑菌实验表明,该精油对7种供试细菌均有抑制作用,对金黄色葡萄球菌（Staphylococcus aureus Roenbach）、普通变形杆菌（Proteasv ulgarisHauser）、甘薯青枯假单胞菌（Ralstonia soanacearum E．F．Smith）、大肠杆菌（Esckrichia coli Castellani et Chalmers）和短小芽孢杆菌（Bacillus pumilus Meyer et Gottheil）的最低抑菌浓度（MIC）为2％,对枯草芽孢杆菌（Bacillus subtilis Cohn）和藤黄八叠球菌（Sarcina lutea Schroeter）的MIC为1％。     

元谋栽培印楝枝叶化学成分研究

从元谋栽培印楝Azadirachta indica的枝叶中分离得到15个化合物,结构类型有三萜、倍半萜、甾体等。经波谱解析鉴定为nimbin（1）,6-deacetylnimbin（2）,6-deacetylnimbinene（3）,nimbinene（4）,azadiradi-one（5）,7-acetoxy-elema-1,3-dien-8-ol（6）,1-naphthalenone（7）,acarusnol（8）,colvane-2β,9α-diol（9）,乌苏酸（10）,马斯里酸（11）,2α-羟基乌苏酸（12）,猕猴桃酸B（13）,2α,3α,4β-trihydroxypregnan-16-one（14）,2β,3β,4β-trihydroxypregnan-16-one（15）。化合物6～15为首次从该植物中分离得到。     

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）。     

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.