祁州漏芦中一个新的三萜皂甙

从祁州漏芦(Rhaponticum uniflorum (L.) DC.)的根中分离得到6个三萜皂甙(1～6),其中化合物3为一新的三萜皂甙,命名为unifloroside,其结构经1D, 2D-NMR及化学方法鉴定为3-O-α-L-arabinopyranosyl-urs-9(11),12-dien-28-oic acid β-D-glucopyranosyl ester.     

白花刺参中两个新三萜皂甙

从著名藏药白花刺参(Morina nepalensis var.alba Hand.-Mazz.)的水溶性部分分离到2个新三萜皂甙--刺参甙K(1)和刺参甙L(2),以及一个已知三萜皂甙mazusaponin I(3).应用波谱和化学方法,刺参甙K和刺参甙L的结构分别鉴定为3-O-α-L-arabinopyranosyl-(1→3)-β-D-xylopyranosyl siaresinolic acid(1)和3-O-β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl siaresinolic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside(2).     

白花刺参中两个新三萜皂甙

从著名藏药白花刺参（Morina nepalensis var.alba Hand.-Mazz)的水溶性部分分离到2个新三萜皂甙-刺参甙K（1）和刺参甙L（2）,以及一个已知三萜皂甙mazusaponinⅠ（3)。应用波谱和化学方法,刺参甙K和刺参甙L的结构分别鉴定为3-O-α-L-arabinopyranosyl-（1→）-β-D-xylopyranosyl siaresinolic acid(1)和3-O-β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl siaresinolic acid28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside(2)。     

多花黄芪的三萜皂甙研究

豆科黄芪属(Astragalus)药用植物的三萜皂甙具有促进微循环和强心作用[1,2],临床上可明显改善心力衰竭病人的心功能。载入青海省新版药品标准[3]的黄芪属植物多花黄芪(AstragalusfloridusBenth.)其化学成分尚未见报道。为科学评价其质量,进一步扩大黄芪药源,作者对多花黄芪的化学成分进行了研究,从其干燥根中提取的总甙粗品部分,经硅胶柱层析和结晶纯化,分得5种三萜皂甙成分,通过光谱分析和化学方法,鉴定为绵毛黄芪甙(1)、黄芪皂甙(2)、黄芪皂甙(3)、绵毛黄芪甙(4)和膜荚黄芪甙(5)[4～7]。实　验　部　分熔点用4显微熔点测定仪测定,温度计…     

蓣知子的化学成份研究（Ⅲ）

从木通科木通属植物白木通[Akebia trifolinta (Thunb.) Koidz. var. australis(Dies)Rehd]的种子(蓣知子)抗肿瘤活性的乙醇提取物中以硅胶层析等方法分得一种三萜皂甙。经波谱分析及酸碱水解确定了其化学结构,命名为:3-O-α-L-吡喃阿拉伯糖常春藤皂甙元-28-O-β-D吡喃葡萄糖-(1→6)-β-D-吡喃葡萄糖甙(即Saponin D),为首次自该植物中获得。     

秦岭产珠子参叶的达玛烷型皂甙研究(1)

从陕西省秦岭产珠子参(Panax japonicus C.A.Meyer var.major(Burk.)Wu etFeng)的叶中分离到十个新的达玛烷型四环三萜皂甙,经光谱测定和化学降解,其中四个的化学结构分别为珠子参甙(majoroside)F_1(1)、F_2(2)、F_3(3)和F_4(4)。同时,还分离到已知的人参甙(ginsenoside)Rd(5)、Re(6)、Rg_1(7)、Rg_2(8)和F_2(9)。     

无患子中两个新的大戟烷型三萜皂甙

从无患子科无患子(Sapindus mukorossi Gaertn.)根中分离到两个新的大戟烷型三萜皂甙Sapimukoside A (1) 和Sapimukoside B (2).运用波谱和化学方法鉴定它们的结构为3-O-α-L-鼠李吡喃糖基-(1→2)-[α-L-阿拉伯吡喃糖基-(1→3)]-β-D-葡萄吡喃糖基-21, 23R-epoxyl tirucall-7, 24R-diene-3β, 21-diol (1) 和3-O-α-L-鼠李吡喃糖基-(1→6)-β-D-葡萄吡喃糖基21, 23R-epoxyl tirucall-7, 24R-diene-3β, 21-diol (2).     

大理产升麻中一个新环阿尔廷三萜皂甙

从升麻(CimicifugafoetidaL.)根茎中分离得到一个新的四环三萜皂甙和5个已知化合物,它们分别是12β-乙酰基升麻醇-3-O-β-D-木糖甙(1),升麻醇(2),25-O-乙酰基升麻醇(3),升麻醇3-O-β-D-升麻醇木糖甙(4),阿科特素(5),小升麻甙B(6)。其化学结构经光谱解析和化学方法鉴定。     

中国特有药用植物铁破锣中的新皂甙类成分

从铁破锣（Beesia calthaefolia(Maxim.)Ulbr.根茎中分离得到5个化合物（1－5）,经化学和波谱学方法鉴定,其中2个为有机酸－铁破锣酸（beesic acid,9-phenyl-2E,4E,6E,8E-nontetraenoic acid,1)和香草酸（2）;3个为齐墩果酸型三萜皂甙：oleanolic acid-3-o－α-Larabinopyranosyl-－28－O-α-L-rhamnopyranosyl-(1→4）-β-D-glucopyranosyl-（1→6）-β-D-glucopyranosyl ester(3),hederasaponin B(oleanolic acid-3-O-α-L-rhamnopyranosyl-(1→2)-α－L-arabinopyranosly-28-Oα-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6）－β－D－glucopyranosyl ester,4)和铁破锣皂甙Q（beesioside Q,oleanolic acid-3-O-β-D-glucopyranosyl-(1→3）－α－L-rhamnopyranosyl-(1→2)-α-L-arabinopyranolsyl-28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6）－β－D－glucopyranosyl ester,5)。化合物1系首次从自然界中分离得到,化合物5为新化合物。     

无患子中两个新的大戟烷型三萜皂甙

从无患子科无患子（Sapindus mukorossi Gaertn.)根中分离到两个新的大戟烷型三萜皂甙SapimukosideA（1）和SapimukosideB（2）。运用波谱和化学方法鉴定它们的结构为3－O－α-L鼠李吡喃糖基－（1→2）-[α-L－阿拉伯吡喃糖基－（1→3）]－β－D－葡萄吡喃糖基－21,23R－epoxyl tirucall-7,24R-diene-3β,21-diol(1)和3－O－α-L－鼠李吡喃糖基－（1→6）－β-D-葡萄吡喃糖基21,23R-epoxyl tirucall-7,24R-diene-3β,21-diol(2)。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV