云南“生态茶”的化学成分

从云南西双版纳产大叶茶（Ｃａｍｅｌｌｉａｓｉｎｅｎｓｉｓｖａｒ．ａｓｓａｍｉｃａ）制成的“生态茶”中分离到１１个化合物和１个混晶,经光谱测定,１１个化合物分别鉴定为没食子酸、（＋）儿茶素、（－）表儿茶素、（－）没食子儿茶素、（－）表没食子儿茶素、（－）表儿茶素－３－０没食子酸酯、（－）表没食子儿茶素－３－Ｏ没食子酸酯、茶素、１,４,６－三役食子酰基－β－Ｄ葡萄糖１－Ｏ－没食子酰基－４,６－（－）－六羟基联苯二甲醚基－β－Ｄ－葡萄糖以及咖啡因;混晶为芦丁和山奈酚－３－芸香糖甙的混合物。这是对国产大叶茶的第一次较详细的化学研究。     

茶叶品种及采摘时节对其活性成分的影响分析

本文利用福林酚法、DPPH和ABTS方法比较分析了宣城市特产茶叶涌溪火青、塔泉云雾、敬亭绿雪、溪口云尖的多酚含量及抗氧化活性。同时还对比分析了敬亭绿雪叶片在不同采收时期的多酚含量及抗氧化活性,并利用HPLC-MS分析了制茶过程对叶片多酚成分的影响。研究结果表明:涌溪火青中多酚含量最高为161mg儿茶素/g样品干重,溪口云尖则含量最少为127 mg儿茶素/g样品干重。相对应的,利用DPPH和ABTS法测得涌溪火青的抗氧化活性最高;通过对敬亭绿雪不同采摘时期中茶多酚含量的研究表明,随着采摘时间的延后,其叶片中茶多酚和抗氧化活性均会有所增加。且敬亭绿雪鲜叶片经制茶过程后其茶多酚含量整体上升,咖啡因含量则有所下降。     

白细胞介素6受体

白细胞介素６受体（ＩＬ－６Ｒ）是造血生长因子受体家族的一员。它由一个８０ｋＤ的配基结合链（ＩＬ－６Ｒ）和作为信号转导子的非配基结合链ｇｐ１３０组成,ＩＬ－６Ｒ既能以膜受体形式存在,也能以可溶性受体形式存在。可溶性白介素６受体（ｓＩＬ－６Ｒ）同样具有膜受体的功能。白介素６受体的表达及调节在某些白介素６相关疾病的发病过程中起着重要作用。     

乌约活性组分LEF的化学成分及抗风湿作用

从乌药（Ｌｉｎｄｅｒａ ａｇｇｒｗｅｇａｔａ（Ｓｉｍｓ）Ｋｏｓｔｅｒｍ）根的镇痛、抗火活性组分（ＬＥＦ）中分离得到６个缩合鞣质烃化合物,鉴定出其中４个,分别为表儿茶素（１）－ｅｐｉｃａｔｅｃｈｉｎ、表榈儿茶素（－）－ｅｐｉｇａｌｌｏｃａｔｅｃｈｉｎ、ｐｒｏｃｙａｎｉｄｉｎＢ－２及ｔｒｉｍｅｒｉｃ ｐｒｏａｎｔｈｏｃｙａｎｉｄｉｎ（ｃｉｎｎａｍｔａｎｎｉｎｓ Ｂ１）,另得到一个黄酮苷,鉴定为橙皮甙ｈ     

紫娟茶化学成分及其抗炎抗氧化活性研究

本文对紫娟茶的化学成分进行分离纯化及其抗炎、抗氧化活性进行考察。实验采用现代分离纯化方法,从紫娟茶中共分离得到12个化合物,根据波谱学数据进行结构鉴定为:山柰酚(1)、(+)-表儿茶素(2)、(-)-表儿茶素-3-O-没食子酸酯(3)、杨梅素(4)、表没食子儿茶素-3-O-(3″-O-甲基)没食子酸酯(5)、槲皮素(6)、没食子酸(7)、表没食子儿茶素没食子酸酯(8)、3-O-没食子酰基奎宁(9)、小木麻黄素(10)、1,4,6-三-O-没食子酰基-β-D-葡萄糖(11)、咖啡因(12),其中化合物9为首次从紫娟茶中分离得到。化合物11表现出良好的抗氧化活性,化合物1、3、4、6、8～11均具有显著的抗炎活性。     

单宁酶的固定化及其在酯型儿茶素水解反应中的应用

采用自制的壳聚糖为载体对单宁酶（ＴＡ）固定化,ＴＡ与壳聚糖配比１：２．５,３０℃固定２ｈ,活力回收达２３．６％～３３．１％;偶联效率为８４．９％～８８．０％。固定化单宁酶（ＩＴＡ）的表观Ｋｍ值（以没食子酸丙酯为底物）为２２．２×１０－６ｍｏｌ／Ｌ,ＴＡ的Ｋｍ值（以没食子酸丙酯为底物）为１０×１０－６ｍｏｌ／Ｌ,ＴＡ和ＩＴＡ的最适反应温度分别为４０℃和５０℃;６０℃处理１５ｍｉｎ,残存活性分别为１３．６％和６０．３％。ＴＡ和ＩＴＡ的最适ｐＨ值分别为５．８和６．４;ＴＡ在ｐＨ４．８～７．８活力稳定,而ＩＴＡ活力稳定范围在ｐＨ４．８～６．８．ＩＴＡ作用于ＥＧＣＧ的半衰期为７８．７ｈ,ＥＧＣＧ水解率达９０．３％。对茶多酚提取物进行水解,其所含的酯型儿茶素ＥＧＣＧ和ＥＣＧ水解率分别为９６．４％和９６．８％,非酯型儿茶素ＥＧＣ和ＥＣ的含量显著增加。     

小麦叶绿体中细胞分裂素结合蛋白的特性

小麦叶绿体中的ＣＴＫ结合蛋白属热敏感蛋白,它与６－ＢＡ结合的最适温度约为２５℃;最适ｐＨ为８左右;在其蛋白分子上存在两类ＣＴＫ结合位点,高亲和力位点与６－ＢＡ结合的Ｋα值为１．１×１０－９ｍｏｌ／Ｌ,低亲和力位点的Ｋα值为９×１０－７ｍｏｌ／Ｌ;激动素、玉米素对６－ＢＡ的结合只有部分抑制作用,而ＡＢＡ、ＧＡ３、ＩＡＡ及腺嘌呤则无竞争作用。ＣＴＫ结合蛋白分子中的中性氨基酸含量很高,在中性介质中带弱负电。     

用染料修饰吐温80液—固萃取体系从猪心肌匀浆液中分离纯化心肌黄酶

用三嗪类染料 Ｃｉｂａｃｒｏｎ Ｂｌｕｅ Ｆ３Ｇ－Ａ修饰的吐温８０,与吐温８０、硫酸被构成液－固萃取体系,从猪心肌匀浆液中分离纯化心肌黄酶。研究了吐温８０染料修饰物在吐温８０相中所占的比例、分相盐浓度、溶液的酸度、匀浆液的加入量等对匀浆液中酶及杂蛋白在两相中分配的影响。在室温条件下,酶选择性地进入吐温８０固相,杂蛋白主要留在盐水相。匀浆液中心肌黄酶的酶活力平均收得率为８１．４％,一步纯化倍数为６．６。降低盐浓度,提高盐水相酸度,能使酶从吐温８０固相反萃到盐水相。     

IL－6受体结构与功能的研究进展

ＩＬ－６是一个多功能的细胞因子,其生物学作用在很大程度上受ＩＬ－６受体（ＩＬ－６Ｒ）结构和功能的影响。ＩＬ－６Ｒ由两条多肽链组成,即配体结合链ｇｐ８０和信号传导链ｇｐ１３０。它们在结构和功能上既有分工又有合作。两种亚基组成的高和力ＩＬ－６Ｒ是介导细胞效应所必需的。ＩＬ－６Ｒα中的造血功能区属于造血因子受体超家族成员,它决定着结合ＩＬ－６的能力,然而ｇｐ１３０则是多种细胞因子共用的信号传递分子,其胞     

海南岛兴隆地区某些药用植物中的微量元素

本文研究海南兴隆地区１２种不同类型药用植物微量元素的生物吸收系数（Ａｘ）及其含量水平变化特性,结果表明不同科、属、种植物对同一元素的吸收量差异显著,以Ｍｇ＞Ａｌ＞Ｆｅ＞Ｍｎ＞Ｚｎ＞Ｃｕ为序;同属不同品种植物在不同生境中对微量元素的生物吸收系数各有差别,海南槟榔（Ａｘ０．３０×１０－６、１２．５１×１０－６）＞泰国槟榔（Ａｘ０．２９×１０－６、１１．５９×１０－６＞云南槟榔（Ａｘ０．２７×１０－６、１１．５６×１０－６）,元素间吸收量相比以Ｍｏ＞Ｚｎ＞Ｃｕ＞Ｍｎ＞Ｎｉ为例;同种植物不同器官微量元素的吸收量也是不同的,例如巴戟天的含量以根（２１８．４８×１０－６＞叶（１１５．１９×１０－６）＞茎（１１３．０２×１０－６）。植物与土壤中元素含量消长变化关系密切,相比之下,植物中Ｆｅ、Ｍｎ、Ｚｎ含量均高于Ｃｕ、Ｐｈ、Ｎｉ。绞股蓝（１８９．２６）＞巴戟天（１６９．０４）＞益智（１６１．７０）＞槟榔（１５５．８８）。     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).