HPLC测定炎消迪娜糖浆中大黄酚的含量

本文用HPLC法测定炎消迪娜儿糖浆中大黄酚的含量。色谱条件：采用Luna 5u C18柱,流动相为甲醇-水（含0．1％醋酸）（98：2,v／v）,检测波长254nm。：大黄酚在0．008～0．088μg（r=0．9997）范围内成线性关系。平均回收率（n=9）为98．79％,RSD为2．24。实验结果表明本法简便,可靠,可用于该制剂的质量控制。     

高效液相色谱法测定红景天根中红景天甙的含量

建立了一种高效液相色谱法测定红景天根中红景天甙的含量。色谱柱为Hypersil—C18（5μm,150mm×4．6mm）,甲醇-水为流动相,梯度洗脱,柱温25℃,在250nm波长处检测。研究结果表明：红景天甙的检测限为50μg/L,线性范围为4—40mg／L,回归方程为Y=5．6348X-4．0931,r=0．9996,加样回收率为98．05％。方法操作简便、快速、准确。     

保健食品中红景天甙含量测定及其稳定性研究

测定保健食品中红景天甙的含量以控制产品质量。采用十八烷基硅烷键合硅胶柱;以乙腈-水（1：9）为流动相,流速为1.0mL／min,检测波长为280nm。结果表明红景天甙在0．4—4．0μg范围内呈线性关系,平均回收率（n=6）为98．96％（RSD=1.16％）。该方法简便、准确、重现性好,可用于保健食品中红景天甙的质量控制。     

西藏红景天组织培养研究

以西藏红景天嫩叶和幼茎为材料,研究西藏红景天不同外植体的离体培养技术。结果表明：西藏红景天嫩叶是诱导愈伤组织和芽的理想外植体,诱导松散型愈伤组织有两种培养基,分别是黑暗培养下MS 6-BA2．0 mg／L NAA0．2mg／L和MS 6-BA3．0mg／L NAA0．3mg／L;生芽培养基为MS 6-BA2．0mg／L IAA0．25mg／L;生根培养基为MS IAA0/5～1．0mg／L。     

4种红景天植物的组织培养研究

以大花红景天、云南红景天、长鞭红景天和库页红景天的茎和叶为外植体进行组织培养,结果表明：大花红景天以茎为外植体诱导芽效果最好,其它3种红景天以叶为外植体诱导芽效果最好。云南红景天和长鞭红景天适合的芽诱导激素组合是0．1mg／L NAA和2．5mg／L 6-BA的组合,在该激素水平下两种红景天的出芽频率分别达到71％和84％;大花红景天和库叶红景天适合的芽诱导激素组合是0．5mg／L NAA和2．5mg／L 6-BA的组合,在该激素水平下两种红景天的出芽频率均达到80％。长鞭红景天和库叶红景天在添加IBA的培养基上容易生根形成完整植株,生根率分别达到87％和73％;经过炼苗后,长鞭红景天再生苗能够成功移栽,成活率达66％。     

高速逆流色谱制备玫瑰红景天中的三种酚性化合物

采用高速逆流色谱方法(HSCCC,High-speed Counter-current Chromatography)同时分离三种玫瑰红景天酚性化合物。玫瑰红景天提取物经聚酰胺吸附多酚后经硅胶柱分级得预分离样品,采用正己烷∶乙酸乙酯∶甲醇∶水(4∶5∶4∶5,v/v/v/v)组成的两相溶剂系统对预分离样品进行分离纯化,一次进样150 mg,一次色谱分离得到化合物1:68.5 mg、化合物2:8.5 mg、化合物3:45.5 mg,纯度都超过98%。通过ESI-MS、1H NMR对其结构进行鉴定化合物1为没食子酸(Gallic acid),化合物2为没食子酸甲酯(Methyl gallate),化合物3为山奈酚(Kaempferol)。结果表明利用HSCCC可以成功分离三种酚性化合物,分离效果好,产品纯度高。     

无籽罗汉果的组织培养和快速繁殖

以无籽罗汉果优良株系的幼嫩茎段为试验材料,经消毒处理后,剪成带一个腋芽的茎段,在MS＋6-BA0．5mg·L^-1＋NAA0．05mg.L^-1培养基上进行培养,获得无菌芽苗,再以无菌芽苗的单芽茎段为外植体,建立无籽罗汉果的组培快繁体系。结果表明,最佳继代增殖培养基为MS＋6-BA0．5mg·L^-1＋IBA0．2mg·^-1＋GA30．03mg·L^-1,30d的增殖系数为16．4;芽苗伸长的最适培养基为MS＋6-BA0．05mg.L^-1＋IBA0．1mg·L^-1＋GA30．1mg·L^-1;芽苗生根的最适培养基为1／2MS＋IBA0．5mg·L^-1：炼苗后,移入蛭石：珍珠岩：熟土=1：1：2（v／v／v）的基质中,成活率达98．1％。该体系的建立为无籽罗汉果规模化生产提供了技术平台。     

甲氨基阿维菌素苯甲酸盐微乳剂热贮稳定性研究

采用高效液相色谱法分析甲维盐微乳剂,以甲醇＋0．2％三乙胺溶液＋乙腈（V：V：V=30：30：40）为流动相,采用XterraRP184．6150mm色谱柱,检测波长245nm,测得54±2℃条件下14d分解率为3．42％。室内毒力测定热贮前后1％甲维盐微乳剂Lc50分别为0．499mg／L和0．524mg／L,热贮分解率为4．78％,与高效液相色谱测定结果基本一致。     

固相萃取-高效液相色谱法测定复合薯片中丙烯酰胺

建立了一种利用固相萃取小柱与高效液相色谱联用,采用光电二极管阵列检测器测定复合薯片中丙烯酰胺的方法。以0．1％的甲酸水溶液为提取试剂,采用Waters Oasis HLB固相萃取小柱（200mg／6cc）对提取液净化处理,然后以流动相为甲醇／水（5：95,V：V）,流速为0．6mL／min,检测波长为210nm,利用AgilentC18反相色谱柱进样分析。在该条件下丙烯酰胺的回收率达80％以上,最低检测限小于10ng／mL。该方法操作简便、重复性好、稳定性高,可用于油炸复合薯片中丙烯酰胺的快速检测。     

反相高效液相色谱法对大鼠体内菲达司他的药代分析

建立反相高效液相色谱（RP—HPLC）测定大鼠血浆中菲达司他浓度的方法,在此基础上对菲达司他在大鼠体内的药代动力学进行初步研究。菲达司他的血浆样品利用乙酸乙酯提取法进行处理,色谱检测条件为用安捷伦Zorbax Eclipse XDB C18色谱柱,紫外检测波长200nm,流动相中v（水）：v（甲醇）为72．28,流速1mL／min,柱温30℃。建立的RP—HPLC法线性范围为0．8～400ug／mL（R=0．9997）。提取回收率大于95％,日内、日间精密度相对标准差（RSD）小于2％。本法简便、准确,适用于菲达司他药代动力学的研究;菲达司他在大鼠体内的药代动力学过程二室模型．     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

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.