染料木素4＇-O-β-D-吡喃木糖苷的合成与表征

以染料木素为原料,采用相转移催化法与乙酰溴代木糖反应,首次选择性地合成了染料木素4＇-O-β-D-吡喃木糖苷。采用聚酰胺柱层析、制备高效液相色谱进行分离纯化得到产物并对其进行了IR、^1H、^13CNMR和MS结构表征。     

迷迭香水溶性物质及抗菌活性研究

采用硅胶柱色谱等方法对迷迭香水溶性提取物进行分离纯化,用^13C NMR、^1H NMR、Ms等方法鉴定出3个化合物：迷迭香酸（1）、香叶木素-7-O-β-D-葡萄糖醛酸甙（2）、木犀草素（3）,其中香叶木素-7-O-β-D-葡萄糖醛酸甙为首次从该植物中发现。对化合物2进行体外抑菌实验,结果为：对金色葡萄球菌和枯草芽孢杆菌均有一定的抑菌作用。     

渐行渐少的红木资源

2000年国家质量技术监督局发布实施了国家标准GB/T 18107-2000《红木》。该标准明确规定了红木定义:紫檀属、黄檀属、柿属、崖豆属及铁刀木属树种的心材,其密度、结构和材色(以在大气中变深的材色进行红木分类)符合《红木》标准规定的必备条件。此外,上述5属中本标准未列入的其他树种的心材,其密度、结构和材色符合《红木》标准的也可称为红木。红木家具承载了中华民族的历史文化,自明清以来,它在中国家具史上独领风骚,一直被誉为家具中的经典。改革开放以后,随着国民经济的高速发展,人民生活水平大幅度提高,红木制品从宫廷走到普通老百姓家,市场欣欣向荣。但是,福兮祸之     

渐行渐少的红木资源

2000年国家质量技术监督局发布实施了国家标准GB/T 18107-2000《红木》。该标准明确规定了红木定义：紫檀属、黄檀属、柿属、崖豆属及铁刀木属树种的心材,其密度、结构和材色（以在大气中变深的材色进行红木分类）符合《红木》标准规定的必备条件。此外,上述5属中本标准未列入的其他树种的心材,其密度、结构和材色符合《红木》标准的也可称为红木。红木家具承载了中华民族的历史文化,自明清以来,它在中国家具史上独领风骚,一直被誉为家具中的经典。改革开放以后,随着国民经济的高速发展,人民生活水平大幅度提高,红木制品从宫廷走到普通老百姓家,市场欣欣向荣。     

美国红木林与红木国家公园

美国红木指生长在美国西北海岸的北美红杉Sequoia sempervirens 与巨杉Sequoiadendron giganteum 的统称。前者称海红木, 分布北加州海岸绵延至俄勒冈州南部州界; 后者称山红木, 分布加州中北部内华达山脉西坡沟谷。它们分别为世界最高和体积最大的长寿植物。红木林是原始复杂的生物群落。红木在史前是北美地区代表植物, 后因环境变迁, 至目前仅剩一个小的生存区域。美国政府为保护现有红木林, 建立了多个红木国家公园和红木州立公园。联合国教科文组织亦将红木国家公园与附近3 个红木州立公园列入世界遗产和国际生物圈保护区中心。红木有多种用途,树形壮丽, 是城市绿化的优良植物。红木公园的巨树与幽谷, 吸引无数游客, 游客绝大部分能自觉遵守有关保护法规。     

雷公藤甲素对哮喘豚鼠外周血CD4^＋和CD8^＋淋巴细胞的影响

探讨雷公藤甲素在治疗哮喘中对外周血T淋巴细胞的影响机制,采用免疫细胞化学方法检测30例豚鼠外周血淋巴细胞CD4^ 、CD8^＋的表达。实验动物分为对照组、哮喘组和雷公藤甲素治疗组（治疗组）,每组各10只。结果表明,治疗组CD4^ 淋巴细胞表达阳性率及表达强度明显低于哮喘组（P＜0.01）,CD8^ 阳性率高于哮喘组（P＜0.05）,与对照组比较差异无显性,本研究认为,雷公藤甲素可能通过增高哮喘豚鼠CD8^ 淋巴细胞,降低CD4^ 淋巴细胞来发挥抗哮喘气道炎症作用。     

红木知识

Q1.硬木是不是红木?硬木指质地细致坚硬的木材(即阔叶材)。硬木是大概念,红木是硬木中约定俗成的一类木材,这两个概念并不一致。2.红色的木材就是红木吗?红色的木材不一定都是红木,红木心材的材色也不全红色的。《红木国标》中共列出5属(紫檀属、黄檀属、柿属、崖豆属和铁刀木属)及AAQQ     

杂色云芝分泌的具有螯合铁离子活性的低分子量成分在木素生物降解中作用机制的研究

从杂色云芝（Coriolus versicolor）培养基中分离到一类低分子量组分,该组分具有螯合Fe^3＋的能力,并能够将Fe^3＋还原为Fe^2＋,推测该组分可能是Fenton反应中的一类电子传递体．将此组分与酶分离木素（cellulolytic enzyme lignin,CEL）作用,并用^1H-NMR,^13C-NMR：离子差光谱及碱性硝基苯氧化方法对作用后CEL的结构变化进行了表征．结果表明,该组分能够破坏非酚型木素中的B-O-4结构,并且能够在非酚型木素结构中添加酚羟基,从而导致木素中形成新的酚型亚结构,使木素更易于被漆酶和锰过氧化物酶降解．因此,该组分可以加速木素降解酶对木素的降解．     

酸枝木类原植物分类学概述

酸枝木类为《红木》国家标准中最大的一类,原植物皆隶属于豆科(Leguminosae)黄檀属(Dalbergia).为准确鉴定红木酸枝木市场的树种,回顾了豆科黄檀属分类学历史,对13种酸枝木的原植物进行了分类学文献考证研究并提供了详细的形态描述.     

天然染料及观赏植物—红木

红木(Bixa orellana L.)又名胭脂木,为红木科多年生常绿灌木或乔木,原产美洲热带地区,我国台湾、华南、云南有少量引种栽培。 红木是一种优质天然染料植物,果实中的红色果瓤,可用于糖果、糕点和各种纺织品染色。红木又是重要的观赏植物,其树形优雅,花、果期长。开花时,色彩鲜艳,花后果实累累,鲜红     

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