法国产夏枯草中的两个新的乌索烷型三萜皂甙

从法国产夏枯草（ＰｒｕｎｅｌｌａｖｕｌｇａｒｉｓＬ．）的甲醇提取物中分离得到两个新的乌索烷型三萜皂甙：夏枯草甙（ｐｒｕｖｕｌｏｓｉｄｅ）Ａ和Ｂ;同时还分离到５个已知化合物：ｎｉｇａ－ｉｃｈｉｇｏｓｉｄｅＦ＿２,ｓｅｒｉｃｏｓｉｄｅ,槲皮素（ｑｕｅｒｃｅｔｉｎ）,槲皮素－３－Ｏ－葡荡糖甙（ｑｕｅｒｃｅｔｉｎ３－Ｏ－ｇｌｕｃｏｓｉｄｅ）,山奈酚－３－Ｏ－葡荡糖甙（ｋａｅｍｐｆｅｒｏｌ－３－Ｏ－ｇｌｕｃｏｓｉｄｅ）,及ａｒｊｕｎｇｌｕｃｏｓｉｄｅⅠ和ｎｉｇａ－ｉｃｈｉｇｏｓｉｄｅＦ＿１的混合物。它们的结构是通过波谱的方法证明的。     

石香薷中化学成分的研究

从石香薷（Ｍｏｓｌａ ｃｈｉｎｅｎｓｉｓ Ｍａｘｉｍ ．）中分离到１０ 个化合物,经光谱分析、化学方法及与已知化合物对照,分别鉴定为：６－甲基三十三烷（１）、β－谷甾醇（２）、熊果酸（３）、５－羟基－６,７－二甲氧基黄酮（４）、５－羟基－６－甲基－７－Ｏ－β－Ｄ－吡喃木糖（３→１）－β－Ｄ－吡喃木糖双氢黄酮甙（５）、５,７－二羟基－４－甲氧基黄酮（６）、洋芹素（７）、山奈素－３－Ｏ－β－Ｄ－葡萄糖甙（８）、桑色素－７－Ｏ－β－Ｄ－葡萄糖甙（９）、鼠李柠檬素－３－Ｏ－β－Ｄ－芹糖（１→５）芹糖－４－Ｏ－β－Ｄ－葡萄糖甙（１０）。其中,化合物５和１０ 为新化合物     

喙果绞股蓝黄酮类化合物的分离及结构测定

从喙果绞股蓝（Ｇｙｎｏｓｔｅｍｍａ　ｙｉｘｉｎｇｅｎｓｅＣ．Ｙ．ＷｕｅｔＳ．Ｋ．Ｃｈｅｎ．）的茎叶分离到７种化合物：喙果黄素（ｙｉｘｉｎｇｅｎｓｉｎ）（Ｉ）、山奈酚（ｋａｅｍｐｆｅｒｏｌ）（Ｉ）、商陆素（ｏｍｂｕｉｎ）（Ⅲ）、商甙（ｏｍ－ｂｕｏｓｉｄｅ）（Ⅳ）、槲皮素（ｑｕｅｒｃｅｔｉｎ）（Ｖ）、异鼠李素（ｉｓｏｒｈａｍｎｅｔｉｎ）（Ⅵ）和硬脂酸（Ⅶ）。其中,喙果黄素为新的黄酮甙,通过光谱分析及化学反应鉴定为商陆素一３－Ｏ－β一Ｄ一葡萄糖成。     

牛至化学成分的研究

从药用植物牛至（Ｏｒｉｇａａｎｕｍ ｖｕｌｇａｒｅ Ｌ．）中分离并鉴定了８个化合物;乌素酸（１）、齐墩果酸（２）、原儿茶酸（３）、日本椴甙（４）、Ｓａｇｉｔｔａｔｏｓｉｄｅ Ａ（５）、胡萝卜甙（６）、β－谷甾醇（７）、豆甾醇（８）。２～５为首次从该种植物中分离得到。     

云木香化学成分研究 II

从丽江产云木香（ＳａｕｓｓｒｅａｌａｐｐａＣ．Ｂ．Ｃｌａｒｋｅ）根中分离得到的另外７化合物,它们分别是孕甾炮醇酮（ｐｒｅｇｎｅｎｏｌｏｎｅ）（１）,β－谷甾醇（β－ｓｉｔｏｓｔｅｒｏｌ）（２）葫萝卜甙（ｄａｕｃｏｓｔｅｒｏｌ）（３）,苯丙素甙（ｓｙｒｉｎｇｉｎ）（４）,木质素甙（１－ｈｙｄｒｏｘｙｐｉｎｏｒｅｓｉｎｏｌ－１－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｉｄｅ）（５）油酸（ｚ,ｚ）－９,１２－ｏ     

藏玄参中的抑精三萜皂甙

从藏药植物藏玄参（ＯｒｅｏｓｏｌｅｎｗａｔｔｉｉＨｏｏｋ．ｆ．）的全草中分离到４个三萜皂甙,密蒙花甙（ｍｉｍｅｎｇｏｓｉｄｅ）Ａ和Ｂ及醉鱼草甙（ｂｕｄｄｌｅｊａｓａｐｏｎｉｎ）Ｉ和Ｉａ,另外还得到阿克甙（ａｃｔｅｏｓｉｄｅ）和６－羟基木犀草素－７－Ｏ－葡萄糖甙（６－ｈｙｄｒｏｘｙｌｕｔｅｏｌｉｎ－７－Ｏ－ｇｌｕｃｏｓｉｄｅ）。体外抑精实验表明,４个三萜皂甙均有较强的抑精活性,其中密蒙花甙Ａ和醉鱼草     

云木香化学成分研究Ⅱ

从丽江产云木香（ＳａｕｓｒｅａｌａｐｐａＣ．Ｂ．Ｃｌａｒｋｅ）根中分离得到的另外７个化合物,它们分别是＿孕甾烯醇酮（ｐｒｅｇｎｅｎｏｌｏｎｅ）（１）,β－谷甾醇（β－ｓｉｔｏｓｔｅｒｏｌ）（２）,葫萝卜甙（ｄａｕｃｏｓｔｅｒｏｌ）（３）,苯丙素甙（ｓｙｒｉｎｇｉｎ）（４）,木质素甙（１－ｈｙｄｒｏｘｙｐｉｎｏｒｅｓｉｎｏｌ－１－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｉｄｅ）（５）,油酸［（ｚ,ｚ）－９,１２－ｏｃｔａｄｅｃａｄｉｅｎｏｉｃａｃｉｄ］（６）和油酸－１,３－甘油二酯［（ｚ,ｚ）－９,１２－ｏｃｔａｄｅｃａｄｉｅｎｏｉｃａｃｉｄ－２－ｈｙｄｒｏｘｙ－１,３－ｐｒｏｐａｎｅｄｉｎｙｌｅｓｔｅｒ］（７）．它们的结构通过波谱和化学的方法得到鉴定。其中化合物１作为天然产物首次从植物中分离得到,化合物３,４,５和７为首次从该植物中分离得到。     

云南永善产蜘蛛抱蛋的甾体成分

从云南省永善县产的百合科植物蜘蛛抱蛋（Ａｓｐｉｄｉｓｔｒａ ｅｌａｔｉｏｒ）根状茎中分离得到８个甾体化合物。其中６个为已知的甾体化合物,分别鉴定为（２５Ｓ）－３β－ｈｙｄｒｏｘｙ－ｓｐｉｒｏｓｔ－５－ｅｎｅ ３－Ｏ－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙｌ（１→）「β－Ｄ－ｘｙｌｏｐｙｒａｎｏｓｙｌ（１→３）」－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙｌ（１→４）－β－Ｄ－ｇａｌａｃｔｏｐｙｒａｎｏｓｉｄｅ     

匙叶翼首花的化学成分

从药用植物匙叶翼首花（Ｐｔｅｒｏｃｅｐｈａｌｕｓ ｈｏｏｋｅｒｉ）中分离了７个化合物。通过波谱分析及已知物数据对照,分别鉴定为ｓｏｎｇｏｒｏｓｉｄｅＡ⑴,ｌｏｇａｎｉｎ⑵,软脂酸（ｐａｌｍｉｔｉｃ ａｃｉｄ,３）,乌索酸（ｕｒｓｏｌｉｃ ａｃｉｄ,４）,齐墩果酸（ｏｌｅａｎｏｌｉｃ ａｃｉｄ,５）,β－谷甾醇（β－ｓｉｔｏｓｔｅｒｏｌ,６）,β－龙胆二糖（β－ｇｅｎｔｉｏｂｉｏｓｅ,７）,其中２是     

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．     

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.     

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.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.