美飞蛾藤（Porana spectabilis Kurz）植物中的化学成分

首次从旋花科飞蛾藤属植物美飞蛾藤（Porana spectabilis Kurz)醇提物中分离鉴定了8个已知化合物,通过波谱方法确定了它们的结构分别为东莨菪素（7－hydroxy-6-methoxycoumarin or soopoletin)(1),东莨菪甙（scoplin)(2);咖啡酸乙酯（ethyl caffeate)(3)和3,5－二羟基肉桂酸（3－（3,5－dihydroxyphenyl)-2E-propenoic acid)(4);α－（D）－甲基呋喃果糖甙（Methylα-Dfrucofuranoside)(5)β－（D）－甲基吡喃果糖甙（Methyl β－D-frucopyranoside)(6);2,5-二羟基基苯甲酸（2,5－dihydroxybenzoic acid)(7);丁香脂素－4－O－β－D－吡喃葡萄糖甙（＋）syringaresinol-4-O-β-(D)-glucopyranoside)(8)。     

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。     

何首乌中新的二苯乙烯甙

用反相层析法从何首乌（Polygonum multiflorum Thunb.)根茎的水提物只发得2个新的二苯乙烯甙（1,2）及9个已知化合物：没食子酸（3）,2,6－二羟基－苯甲酸（4）,吲哚－3－（L－）α氨基－α－羟基－丙酸）甲酯（5）1,2－二羟基丙烷－1－（4－羟基－苯基）（6）,大黄素（7）,大黄素－8－β－D－葡萄糖甙（8）,（＋）－lyoniresinol-3α－O－β－D－葡萄糖甙（9）,2,3,4、,5－四羟基反式二苯乙烯－2－O－β－D－吡喃葡萄糖甙（10）和2,3,4',5－四羟基反式二苯乙烯－2,3,－二－O－β－D－吡喃葡萄糖甙（11）。亲化合物结构通过理化性质与波谱分析特别是2D NMR得以确定。化合物2表现出很强的DNA裂解活性,化合物1,2与10具有很强的抗脂质过氧化活性。     

青檀树皮中的化学成分

从我国特有的单种属药用植物青檀（Pteroceltis tatarinowii Maxim.）的树皮中分离鉴定出10个化合物,其结构分别为：N－p－香豆酰酪胺（paprazine,1）、丁香脂酚－4－O－β－D－葡萄糖甙（2）、丁香脂酚－4,4′－二－O－β－D－葡萄糖甙（liriodendrin,3）、甲基丁二酸（4）,香草酸（5）、甲基肌醇（6）、β－谷甾醇（7）、胡萝卜甙（8）、α－香树素（9）和β－香树素混合物（10）。这些化合物均为首次从青檀树皮中分离得到,其中化合物3为主要成分。     

黄白红菇的化学成分

从野生真菌黄白红菇Russula ochroleuca(Pers).Fr.子实体中首次分得11个化合物,经光谱法和化学法分别鉴定为2个脑苷脂,1－0－β－D－吡喃葡萄糖基－（2S,3R,4E,8EE,2'R）－2－N－(2'－羟基棕榈酰）－9－甲基－4,8－sphingadienine(cerebrosideB,1)和1－O－β－D－啉喃葡萄糖基－（2S,3R,4E,8E,2'R) -2-N-(2'-羟基十八酰B,I）和－9－甲基－4,8－sphingadienine(cerebrosideD,2);3个麦角甾醇,5α,8α－epidioxy-(22E,24R)-ergosta-6,22-dien-3β-ol3,(22E,24R)-ergosta-7,22-dien-3β-ol4,(24S)－ergosta-7-en-3β-ol5.2个含氮杂环化合物,尿嘧啶（uracil6),腺嘌adenine7),1个含硫化合物,硫代乙酰酐（thioacetic anhydride8),以及乙基－β－D－吡喃呤（adenine7),1个含硫化合物,硫代乙酸酐（thioacetic anhydride8),以及乙基－β－D－吡喃葡萄糖苷（ethy1-β－D－glucopyranosde9),D－阿洛醇（D-allitol10),硬脂酸（stearic acid11),化合物1和2为首次从红菇科真菌获得,8作为天然产物系首次报道。     

小叶臭黄皮的黄酮苷甙成分

从云南西双版纳的小叶臭黄皮（Clausena excavata Burm.f.）中分离到一个新黄酮甙,5,7,5′－三羟基－3′,4′－二甲氧基黄酮3－0－α－L－吡喃鼠李糖甙（1）和4个已知黄酮甙,分别为5,7,3′,5′－四羟基－4′－甲氧基黄酮3－O－α－L－吡喃鼠李糖甙（2）,5,7,3′－三羟基－4′－甲氧基黄酮3－O－α－L－吡喃鼠李糖甙（3）,5,7,4′－三羟基－3′,5′－二甲氧基黄酮3－O－α－L－吡喃鼠李糖甙（4）,5,7,4′－三羟基黄桐3－O－α－L－吡喃鼠李糖甙（5）。根据HMQC、HMBC实验修正了化合物2－5C6和C8的位碳化学位移的归属。     

弯蕊开口箭中的新甾体配糖体

从百合科植物弯蕊开口箭（Tupistra Hook,f．）的根茎中分离得到4个新的甾体配糖体,分别命名为弯蕊苷（wattoside)B-E(1-4),其中,3个多羟基呋甾型配糖体,另1个为强心苷,经化学降解和光谱分析,其化学结构分别鉴定为：22－0－甲基－25（R,S）,－呋甾烷－1β,3β,4β5β,22ξ,26β－六醇－26－O－β－D－葡萄吡喃糖苷（1）：22－O－甲基－26－O－β－D-葡萄吡喃糖基－25（S）－呋甾烷－5－烯－β,3β,22ξ,26β－甲醇－3－0－[O-β-D-葡萄吡喃糖基（1－4）]－β－D-半乳吡喃糖苷（2）;22－0－甲基－25（S)-呋甾烷－1β,2β,3β,4β,5β,22,26β－七醇－26－O-β－D－葡萄吡喃糖苷（3）和夹竹桃苷元－3－O－[O-β-D-葡萄吡喃糖基（1－2）]－α－L－鼠李吡喃糖苷,弯蕊苷E为开口箭属植物中首次分离到的强心苷。     

长缘厚朴中的新配糖体

从长缘厚朴（Magnolia rostrata W.W.Smith)干燥树皮的乙醇提取物中分离得到一个新的配糖体,1,1'－联苯－6',8',9'-三羟基－3－丙基－4－O－β－D吡喃葡萄糖苷（1）,以及6个已知的苯丙素类配糖体,3,4－二羟基－烯丙基－3－O－α－L－吡喃鼠李糖（1→6）β－D－吡喃葡萄糖苷（2）,3,4－二羟基－烯丙基苯－3－O－α－L－吡鼠李糖（1→2）β－D－吡喃葡萄糖苷（3）,sinapaldehyde(E)-O-β-D-glucopyranoside(4),syringaresinol-di-O-β-D-glucopynanoside(5),A阿克苷（E）（6）,IcarisideE5(7),经光谱和化学方法鉴定其结构。     

牛心朴子须根的化学成分研究

从采自宁夏的萝摩科鹅绒藤属植物牛心朴子 (CynanchumkomaroviiAl.Iljinski.)须根的乙醇提取物中分离鉴定了十个非C2 1 甾体类化合物 :β D 呋喃果糖基 (2→ 1) α D [6 O 芥子酰基 ] 吡喃葡萄糖甙 (1) ,β D (3 O 芥子酰基 ) 呋喃果糖基 (2→ 1) α D [6 O 芥子酰基 ] 吡喃葡萄糖甙 (2 ) ,[6 O β D 吡喃葡萄糖基 (1→ 6 ) β D 吡喃葡萄糖基 1,2 双氧 (4 羟基 3,5 二甲氧基肉桂酰 ) (3) ,7 脱甲氧基娃儿藤碱 (4) ,9 羟基 芳樟醇 3 O β D 吡喃木糖基 (1→ 6 ) β D 吡喃葡萄糖甙 (5 ) ,(2E ,6R) 2 ,6 二甲基 2 ,7 辛二烯 1,6 二醇 (6 ) ,[(+) 丁香素 ](7) ,4′ O demethylepiyangambin(8) ,4′ 羟基 2′ 甲氧基苯乙酮 (9) ,(2S ,3S ,4R ,12E) N [2′ (R) 羟基二十二碳烷基 ] 1,3,4 三羟基 2 酰胺 二十碳烷基 12 烯 (10 )。除化合物 4和 9外 ,其余化合物均为首次从该植物中分离得到。     

白穗花的甾体皂甙

从中国特有植物白穗花（Speiranthagardenii（Hook．）Baill．）根茎中分离得到两个新的甾体皂甙。经化学和光谱方法鉴定其化学结构分别为22－甲氧基－（25R）－5β－呋喃甾烷－1β,3β,4β,5β,26-五羟基26－O-β-D-吡喃葡萄糖甙（Ⅰ）和22-甲氧基-（25R）－5β-呋喃甾烷-1β,2β,3β,4β,5β,26-六羟基26－O－β-D-吡喃葡萄糖甙（Ⅱ）。     

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.