圆穗蓼中的新黄酮甙成分

从圆穗蓼（Ｐｏｌｙｇｏｎｕｍ ｓｐｈａｅｒｏｓｔａｃｈｙｕｍ Ｍｅｉｓｎ．）中分离得到２个新黄酮甙,经光谱分析和化学方法鉴定为：３＇－羟基－５,４＇－二甲氧基－６,７－二氧亚甲基黄酮－３－Ｏ－「β－Ｄ－吡喃木糖基（１→６）」－β－Ｄ－吡喃葡萄糖甙⑴和５,４＇－二甲氧基－３＇－异丙烯基乙酰基－６,７－二氧亚甲基黄酮－３－Ｏ－「β－Ｄ－吡喃木糖基（１→６）－β－Ｄ－吡喃葡萄糖甙⑵,分别命名为圆穗蓼素Ａ     

单条草的皂甙成分

从单条草（ＬｙｓｉｍａｃｈｉａｃａｎｄｉｄａＬｉｎｄｌ）全草中分离出３个皂甙类化合物,经波谱分析并结合化学方法鉴定为：报春花素Ａ３ＯβＤ吡喃木糖基（１→２）βＤ吡喃葡萄糖基（１→４）［βＤ吡喃葡萄糖基（１→２）］αＬ吡喃阿拉伯糖甙（１）、原报春花素Ａ３ＯβＤ吡喃木糖基（１→２）βＤ吡喃葡萄糖基（１→４）［βＤ吡喃葡萄糖基（１→２）］αＬ吡喃阿拉伯糖甙（ｌｙｓｉｋｏｉａｎｏｓｉｄｅ,２）和α菠甾醇葡萄糖甙（３）。其中１是新化合物,命名为单条草甙（ｃａｎｄｉｄｏｓｉｄｅ）。     

红木荷树皮的化学成分

从红木茶树皮中分离出４个化学成分,经光谱解析和化学降解,分别被鉴定为α－菠甾醇,α－菠甾醇葡萄糖甙,表儿茶素和一新的三萜皂甙２２－Ｏ－当归酰酯－３－Ｏ（α－Ｌ－鼠李吡喃糖基（１→２））－（β－Ｄ－葡萄吡喃糖基（１→２）－β－Ｄ－半乳吡喃糖基（１→４））－β－Ｄ－葡萄糖醛酸甙。     

仙茅根茎中的配糖体

从仙茅（ Ｃｕｒｃｕｌｉｇｏ ｏｒｃｈｉｏｉｄｅｓＧａｅｒｔｎ） 根茎中分离到７ 个化合物, 经光谱分析推定其化学结构分别为： ２, ６ － 二甲氧基苯甲酸（Ａ） ; 苔黑酚葡萄糖甙（Ｂ） ; 仙茅素Ａ （Ｃ） ; 仙茅甙（Ｄ） ; ２４ｓ, ３β, １１α, １６β, ２４ － 四羟基环阿尔廷醇－ ３ － Ｏ－ α－ Ｌ－ 鼠李吡喃糖基（１ →２） － β－Ｄ－ 葡萄吡喃糖甙（Ｅ） ; ２４ｓ, ３β, １１α, １６β, ２４ － 四羟基环阿尔廷醇－ ３－ Ｏ－ β－ Ｄ－ 葡萄吡喃糖基（１ →２） － β－ Ｄ－ 葡萄吡喃糖甙（Ｆ） 和胡萝卜甙（Ｇ） 。Ｆ为一新甙。     

慈溪麦冬甙A和B的结构

从浙江慈溪产中药麦冬（Ｏｐｈｉｏｐｏｇｏｎ ｊａｐｏｎｉｃｕｍ）中分离得到２个新的Ｃ２７甾体甙－－慈溪麦冬甙Ａ（２）和Ｂ（３）以及已知甙ｏｐｈｉｏｇｅｎｉｎ３－氧－α－Ｌ－鼠李糖吡喃基（１→２）「β－Ｄ－木糖吡喃基（１→３）」－β－Ｄ－葡萄糖吡喃甙（２）和ｏｐｈｉｏｇｅｎｉｎ ３－氧－α－Ｌ－鼠李糖吡喃基（１→２）「β－Ｄ－木糖吡喃基（１→３）」「β－Ｄ－葡萄糖吡喃基（１→４）」－β－Ｄ－葡萄糖吡     

婆婆针的化学成分

婆婆针（ＢｉｄｅｎｓｂｉｐｉｎｎａｔａＬｉｎｎ）是具有清热解毒功能的民间药用植物,从婆婆针的地上部分分离鉴定了３个苯丙素甙类化合物,４－Ｏ－（６″－Ｏ－对香豆酰基－β－吡喃葡萄糖）－对－香豆酸（１）,４－Ｏ－（２″－Ｏ－乙酰基－６″－Ｏ－对－香豆酰基－β－Ｄ－吡喃葡萄糖）－对－香豆酸（２）及４－Ｏ－（２″,４″－Ｏ－二乙酰基－６″－Ｏ－对－香豆酰基－β－Ｄ－吡喃葡萄糖）－对－香豆酸（３）,其中（３     

麦冬的配糖体成分

从川麦冬（Ｏｐｈｉｏｐｏｇｏｎ ｊａｐｏｎｉｃｕｓ）根部乙醇提取物中分离得到四个已知化合物,经波谱分析确定其结构分别为：龙脑７－Ｏ－β－Ｄ－吡喃葡萄糖甙（１）,龙脑７－Ｏ－〔β－Ｄ－呋喃芹糖（１→６）〕－β－Ｄ吡喃葡萄糖甙（２）,４－烯丙基－１,２－苯本酚１－Ｏ－〔α－Ｌ－吡喃鼠李糖（１→６）〕－β－Ｄ－吡喃葡萄糖甙（３）,５－烯－１β,３β,１６β,２２Ｓ－胆甾四醇１－Ｏ－α－Ｌ－吡喃鼠李糖１６     

鞭打绣球中的苯丙素甙和环烯醚萜甙

从鞭打绣球（ＨｅｍｉｐｈｒａｇｍａｈｅｔｅｒｏｐｈｙｌｌｕｍＷａｌｌ．）（玄参科）的全草中分离到２个新的苯丙素甙,命名为鞭打绣球甙Ａ和Ｂ（ｈｅｍｉｐｈｒｏｓｉｄｅＡａｎｄＢ）,２个已知的苯丙素甙,ｐｌａｎｔａｍａｊｏｓｉｄｅ和ｐｌａｎｔａｉｎｏｓｉｄｅＤ,以及３个已知的环烯醚萜甙,ｇｌｏｂｕｌａｒｉｃｉｓｉｎ,ｇｌｏｂｕｌａｒｉｎ和ｉｓｏ－ｓｃｒｏｐｈｕｌａｒｉｏｓｉｄｅ．通过化学和光谱分析,鞭打绣球甙Ａ和Ｂ的结构分别鉴定为２－（３－羟基－４－甲氧基苯基）乙基０－β－Ｄ－葡萄吡喃糖基（１→３）－４－Ｏ－反式阿魏醚基－β－Ｄ－葡萄吡喃糖试和２－（３,４－二羟基苯基）乙基Ｏ－［６－Ｏ－乙醚基－β－Ｄ－葡萄吡喃糖基（１→３）］－４－Ｏ－反式咖啡醚基－β－Ｄ－葡萄吡喃糖甙．     

日本续断中新五糖皂甙的结构及其核磁共振光谱

从日本续断（Ｄｉｐｓａｃｕｓ ｊａｐｏｎｉｃｕｓ Ｍｉｑ．）根的乙醇提取物中分得一个新的三萜皂甙,其结构被鉴定为３．－Ｏ－〖β－Ｄ－吡喃葡萄糖（１→）〗〖α－吡喃鼠李糖（１→３）〗－β－Ｄ－吡喃葡萄３９糖（１→３）－α－Ｌ吡喃鼠李糖（１→２）－α－吡喃阿拉伯糖－齐墩酸。采用一维ＳＥＭＤＹ谱和转坐标ＮＯＥ差谱核磁共振新技术相结合的方法,对糖体间和９糖体与甙元间的连接顺连接位置进行了研究。该方法的结果     

滇重楼地上部分的配糖体

从滇重楼ＰａｒｉｓｐｏｌｙｐｈｙｌｌａＳｍ．ｖａｒ．ｙｕｎｎａｎｅｎｓｉｓ（Ｆｒ．）Ｈ－Ｍ,地上部分,分离出４个微量的配糖体,经光谱分析和化学降解证明其化学结构分别为２５Ｓ－异钮替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃甙（Ａ）,２６－β－Ｄ－葡萄吡喃糖基－纽替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）－β－Ｄ－葡萄吡喃糖甙（Ｂ）,山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄吡喃甙（Ｃ）,７－Ｏ－α－Ｌ－鼠李吡喃糖基－山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄糖甙（Ｄ）。     

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     

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.