抱茎獐牙菜的San酮甙和黄酮甙

从龙胆科植物抱茎獐牙菜（Swertia franchtiana H.Smith)中分得3种San酮甙,1种黄酮甙和1种三萜酸,通过光谱和化学等方法,分别鉴定为当药醇甙,当药黄素,芒果甙,1－O－[β－D－吡喃木糖－（1－6）－β－D－吡喃葡萄糖],－3,5－二甲氧基San酮（XI）和齐墩果酸,其中晶XI为一新化合物。     

抱茎獐牙菜的San酮甙和黄酮甙

从龙胆科植物抱茎獐牙菜（Swertia franchtiana H.Smith)中分得3种San酮甙,1种黄酮甙和1种三萜酸,通过光谱和化学等方法,分别鉴定为当药醇甙,当药黄素,芒果甙,1－O－[β－D－吡喃木糖－（1－6）－β－D－吡喃葡萄糖],－3,5－二甲氧基San酮（XI）和齐墩果酸,其中晶XI为一新化合物。     

滇黄芩中的两个酮甙

从龙胆科滇黄芩属植物滇黄芩(Veratrilla baillonii Franch.)中分离得到两个新的(口山)酮甙,分别命名为:滇黄芩甙C(I)和滇黄芩甙D(Ⅱ).经各种光谱解析及化学反应证明,其结构推定为:2,3,4,5-四甲氧(口山)酮-1-O-β-D-吡喃葡萄糖基(6←l)-β-D-吡喃木糖甙(I)和3,4,5-三甲氧基(口山)酮-1-O-β-D-吡喃葡萄糖基(6←1)-β-D-吡喃本糖甙(Ⅱ).     

川西獐牙菜甙类成分

对川西獐牙菜(Swertia mussotii Franch.)的水溶性成分进行了研究。应用层析方法,分离得到裂环烯醚萜甙,黄酮甙,(口山)酮甙,3类8种单体成分(Ⅰ—Ⅷ)。除先前报道过的芒果甙外(Ⅱ),又分离和鉴定了苦龙甙(Ⅲ),当药黄素(Ⅷ),8-O-β-D-吡喃葡萄糖-1,3,5-三羟基(口山)酮(Ⅶ),8-O-[β-D-吡喃木糖-(1→σ)-β-D-吡喃葡萄糖]-1,7-二羟基-3-甲氧基(口山)酮(Ⅵ)4种已知天然化合物。应用化学和光谱分析方法,测定另外3种新(口山)酮甙的结构为:7-O-[α-L-吡喃鼠李糖-(1→2)-β-D-吡喃木糖]-1,8-二羟基-3-甲氧基咄酮(Ⅰ),7-O-β-D-吡喃木糖-1,8-二羟基-3-甲氧基(口山)酮(Ⅳ),3-O-β-D-吡喃葡萄糖-1,8-二羟基-5-甲氧基(口山)酮(Ⅴ)。芒果甙,苦龙甙和7-O-[α-L-吡喃鼠李糖-(1→2)-β-D-吡喃木糖]-1,8-二羟基-3-甲氧基(口山)酮为川西獐牙菜主要甙类成分。有兴趣的是在已发现的龙胆科植物(口山)酮糖甙中,未见(口山)酮木糖甙,(口山)酮鼠李糖-木糖甙的报道。     

白首乌甙A,B和C的结构

从著名中药白首乌(Cynanchum auricutatum Royle ex Wight)根中分离得到7个C_2(?)体甙。其小4个已知物——wilfosidc C3N (Ⅰ), C1N (Ⅱ), C1G (Ⅲ), K1N (Ⅴ),和另外3个新C_(21)甾体甙,命名为白首乌甙A (Ⅵ),B (Ⅶ),C(Ⅳ) (cynauricusidc A, B,C)。经光谱数据分析和化学反应,证明其结构分别为:开德甙元 3-氧-β D-葡萄糖吡喃基-(1→4)-α-L-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-(1→4)-α-L-迪吉糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃甙(kidjoranin 3-O-β-D-glucopyranosyl-(1→4)-α-L-cymaropyranosy-(1→4)-β-D-cymaropyranosyl-(1→4)-α-L-diginopyranosyl-(1→4)-β-D-cymaropyranoside, Ⅵ);萝藦甙元 3-氧-α-L-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-α-L-迪吉糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃甙(metaplexigenin -O-α-L-cymaropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-α-L-diginopyranosyl-(1→4)-β-cymaropyranoside,Ⅶ);告达庭 3-氧-β-D-葡萄糖吡喃基-(1→4)-β-L-葡萄糖吡喃基-(1→4)-α-L-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-(1→4-α-L-迪吉糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基(caudatin 3-O-β-D-glucopyranosy-(1→4)-β-D-glucopyr     

云南匙羮藤甙A和B的结构

从云南匙羹藤(Gymnema yunnaflense Tsiang)中分离得到2个新C_(21)甾体甙,命名为云南匙羹藤甙A(Ⅰ)和B(Ⅱ)(gymnemaroside A, B)。据化学反应和光谱数据,推定其结构分别为:本波甙元3-氧-β-D-葡萄糖吡喃基-(1→4)-3-氧-甲基-6-去氧-β-D阿洛糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃甙〔penupogenin 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside〕和吉马甙元3-氧-β-D-葡萄糖吡喃基-(1→4)-3-氧-甲基-6-去氧-β-D-阿洛糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃甙〔symnemarsgenm 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→d)-β-D-cymaropyranoside〕。     

丝瓜中一个新脑甙脂类化合物

在继续研究鲜丝瓜果实成分时,又分离出3个化台物,其一(L-I)为一新脑甙脂,mp、140°～142℃,分子式:C_(39)H_(73)O_9N,它的结构经理化及光谱(IR、MS、HNMR、~(13)CNMR)数据确定为N-[D-2~1羟基十四烷酰基]-1-O-[β-D-吡喃葡萄糖)-D-赤式-十九鞘氨-4(E),8(E)-二烯醇,命名为Lucyobroside。另2个化合物(L-Ⅱ与L-Ⅲ)为已知五环三萜皂甙,即3-O-[β-D-吡喃葡萄糖)-常春藤甙元-28-O-β-D-吡喃葡萄糖甙(Lucyoside E);3-O-β-D-吡喃葡萄糖]-丝石竹甙元-28-O-β-D-吡喃葡萄糖甙(Lucyoside F),此两皂甙均系首次从我国产丝瓜中分得。     

细萼扁蕾的化学成分研究

从细萼扁蕾(Gentianopsis barbata var.stennocaryx H.W.Li ex T.N.Ho)全草中分离得到9种化合物,6种(口山)酮成分,1种黄酮甙,2种三萜酸。经化学和光谱方法,分别鉴定为1-羟基-3,7,8-三甲氧基(口山)酮(Ⅰ),1,7-二羟基-3,8-二甲氧基(口山)酮(Ⅱ),1,7,8-三羟基-3-甲氧基(口山)酮(Ⅲ),1-O-[β-D-吡喃木糖-(1→)-β-D-吡喃葡萄糖]-3,7,8-三甲氧基(口山)酮(Ⅳ),1-O-[β-D-吡喃木糖-(1→6)-β-D-吡喃葡萄糖]-7-羟基-3,8-二甲氧基(口山)酮(Ⅴ),1-O-[β-D-吡喃木塘-(1→6)-β-D-吡喃葡萄糖]-7,8-二羟基-3-甲氧基(口山)酮(Ⅵ),木樨草素-7-O-β-D-葡萄糖甙(Ⅶ),齐墩果酸(Ⅷ)和熊果酸(Ⅸ)。     

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.     

滇黄芩甙A和B的结构

从龙胆科滇黄芩属植物滇黄芩(Veratrilla baillonii Franch)中分离得到两个新的酮二糖甙,经~1H NMR,~(13)C NMR,FAB-MS,MS,2D NMR,UV,IR等物理方法和化学反应,推定为:2,3,4,7-四甲氧基酮-1-O-β-D-葡萄糖(6←1)-β-D-木糖甙(1)和7-羟基-2,3,4-三甲氧基酮-1-O-β-D-葡萄糖(6←1)-β-D-木糖甙(2),分别命名为:滇黄芩甙A和滇黄芩甙B。     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细