反相高效液相色谱法测定不同品种花椒中芦丁和槲皮素的含量

目的:建立RP-HPLC测定花椒中芦丁与槲皮素含量的方法,并对不同种花椒的中芦丁与槲皮素含量进行测定与比较。方法:Zorbax Eclipse C18色谱柱(150 mm×4.6 mm,5μm),流动相∶甲醇-0.4%磷酸(50∶50);流速1 mL/min;检测波长:360 nm;柱温25℃。结果:芦丁在0.25~5.0μg,r=0.999 9峰面积与质量浓度呈良好的线性关系;平均回收率为99.1%,RSD为4.3%(n=3)。槲皮素在0.25~0.5μg,r=0.999 9峰面积与质量浓度呈良好的线性关系;平均回收率为111.2%,RSD为5.1%(n=3)。结论:该方法可用于花椒中芦丁和槲皮素的测定。测定结果表明,韩城红花椒中芦丁含量最高,茂汉红花椒次之,四川青花椒较少,云南青花椒最低。槲皮素在韩城红花椒中含量较高,在其他三种花椒中差别不大。     

壮、瑶药小槐花中异柠檬酚的分离鉴定及含量测定研究

采用硅胶色谱柱分离纯化的方法从小槐花药材中分离得到一种黄酮类化合物,根据理化性质及光谱数据鉴定其为异柠檬酚。采用HPLC法对异柠檬酚的含量进行测定,HPLC分析条件如下:色谱柱为Agilent ZORBAX SB-C18(250 mm×4.6 mm,5μm),流动相为甲醇-0.2%磷酸水溶液(70∶30),流速为1.0 mL/min,检测波长为270 nm,柱温为35℃。实验结果表明异柠檬酚在0.011~0.242μg范围与其峰面积呈良好的线性关系;平均回收率为99.76%,RSD为1.42%(n=6),不同采集地的小槐花药材中异柠檬酚的含量存在一定差异。     

高效液相色谱法同时测定荷叶中6种黄酮类成分

为了探索同时测定荷叶茶及饮片中6种黄酮类成分(芦丁、金丝桃苷、紫云英苷、槲皮素、山奈素和异鼠李素)含量的方法,本研究以8种不同的荷叶样本为材料,采用高效液相色谱分析法对6种黄酮类成分进行了同时测定。样品经过前处理,以0.5%甲酸-水(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱,流速为1mL/min,柱温为25℃,进样量为20μL,经Agilent TC-C18(2)(150mm×4.6mm,5μm)色谱柱分离,于360nm波长处检测,结果显示,芦丁、金丝桃苷、紫云英苷、槲皮素、山奈酚、异鼠李素6种黄酮类成分分别在1.6~160、1.8~180、2.16~216、1.4~140、2.12~212、1.6~160μg/mL浓度范围内有良好的线性关系(R20.9992),其检测稳定性、重复性、日内精密度、日间精密度以及加样回收率的RSD均小于2%。进一步用该方法对不同来源的8个荷叶样本进行检测,结果显示荷叶样本中6种黄酮类成分含量以槲皮素最高,并且以样本G荷叶茶(购自G公司,批号为130802)的槲皮素含量最高。本研究建立的同时测定6种荷叶黄酮类成分含量的方法快速、准确,可为荷叶有效成分的检测和质量控制提供技术支撑。     

川楝子中香草酸含量测定研究

本实验采用薄层色谱法对川楝子中香草酸、异香草酸进行定性鉴别;采用高效液相色谱法对川楝子中香草酸进行含量测定。色谱柱:Hypersil BDS C18(250 mm×4.60 mm,5μm),柱温:30℃,流动相:甲醇∶水∶冰乙酸=25∶75∶0.5,流速:1.0 mL.min-1,检测波长:260 nm。最终,定性鉴别斑点清晰。结果表明香草酸含量在1.022～16.352μg范围内,进样量与峰面积呈良好线性关系,相关系数r=0.9998;香草酸的平均回收率为102.45%,RSD=1.22%(n=6)。     

RP-HPLC法测定盐肤木中桦木酸和桦木醇含量的方法

为了建立盐肤木中RP-HPLC法测定桦木酸、桦木醇含量的方法,采用正交试验法,以桦木酸、桦木醇的含量为指标,采用料液比为1∶20,乙醇浓度为60%,提取温度为50℃作为提取工艺;采用Hypersil-C18色谱柱(250 mm×4.6 mm, 5μm),以乙腈-水-磷酸(89∶10∶0.1)为流动相,体积流量0.8 mL·min~(-1),柱温为室温,进样量20μL,灵敏度1.00 AUFS,检测波长为205 nm。盐肤木中桦木酸、桦木醇分别在在5.2～52μg·mL~(-1)(r=0.9996)、10.8～108μg·mL~(-1)(r=0.9995)范围内与峰面积线性关系良好,平均加样回收率为99.3%(RSD=1.6%)、99.0%(RSD=0.9%)。该方法简便、稳定、重复性好,可用于盐肤木根茎的质量控制。     

新疆戈宝麻花、种子及叶片部位芦丁含量比较

目的:比较新疆戈宝麻花、种子、叶片中芦丁的含量。方法:采用回流提取法提取芦丁,高效液相层析法法测定新疆戈宝麻不同部位中芦丁的含量。色谱柱为Eclipse-C18柱(4.6 mm×150 mm, 5 um);流动相为乙腈-0.25%磷酸溶液(V/V,14.5∶85.5);流速为1.0 mL/min;柱温为30℃;检测波长为360 nm;进样量为20 uL。结果:芦丁含量在0.01～0.1 mg/mL范围内与峰面积呈良好的线性关系,相关系数为0.993 6;其中花、种子、叶片中芦丁得率分别为:0.094%、0.014%、0.6%。结论:新疆戈宝麻不同部位芦丁的含量分布为:叶﹥花﹥种子,上述结果可为增加戈宝麻新药源和新的药用部位开发利用提供有力依据。     

高效液相色谱法测定甜菊糖苷中甜菊醇的含量

建立高效液相色谱法测定甜菊糖苷中甜菊醇的含量。色谱条件:色谱柱为Phenomenex C18(4.6 mm×250 mm,5μm);流动相为乙腈-水(50∶50);流速1.0 mL/min;检测波长213 nm;柱温30℃;进样量10μL。线性范围为1.046μg/mL~52.3μg/mL(r=0.9997),加标平均回收率为96.60%,RSD为0.51%(n=6)。本方法准确度高、精密度高、重复性好、简捷易操作,可以作为甜菊糖苷中甜菊醇含量的测定方法。     

利用SEC-HPLC法测定重组人透明质酸酶的纯度

目的:建立检测重组人透明质酸酶(rHuPH20)纯度的高效分子排阻色谱法(SEC-HPLC)。方法:利用SEC-HPLC法建立检测rHuPH20纯度的方法,并对方法的专属性、线性、精密度(重复性和中间精密度)、检测限、定量限和耐用性等指标进行评估。结果:空白溶剂在设定的积分范围内无特异峰出现;样品浓度为30~480μg/m L时,数据呈线性关系,决定系数r~2=0.9994;重复性实验峰面积相对标准偏差(RSD)为1.9%;中间精密度实验峰面积RSD为1.1%;检测限为样品浓度10μg/m L时进样体积20μL,即进样量0.2μg;定量限为样品浓度30μg/m L时进样体积20μL,即进样量0.6μg;耐用性实验中,峰保留时间RSD为0.4%,峰面积RSD为1.0%。结论:建立的SEC-HPLC法各项指标符合要求,可用于rHuPH20的纯度检测。     

HPLC法测定神安颗粒中五味子醇甲含量的研究

以高效液相色谱法测定神安颗粒中五味子醇甲含量,建立神安颗粒多指标质量控制体系中脂溶性成分的控制指标。采用Kromasil C18色谱柱,流动相为甲醇-水(60∶40),检测波长为250 nm,流速为1.0 m L/min,柱温为室温,进样量为10μL。结果五味子醇甲进样量在0.15~6.0μg范围内与峰面积积分值线性关系良好(R2=1),平均回收率为97.38%(RSD=2.05%),测定神安颗粒中五味子醇甲含量约为1.30 mg/g。本方法简便、快捷、专属性强、重现性好,可用于神安颗粒天麻苷类成分的质量控制。     

高效液相色谱法测定消瘀跌打药酒中姜黄素的含量

目的建立高效液相色谱法测定消瘀跌打药酒中姜黄素的含量。方法采用Agilent Eclipse XDB-C18柱(250 mm×4.6 mm,5μm),流动相为乙腈-4%冰醋酸溶液(47∶53),检测波长430 nm,流速为1 ml·min~(-1),柱温为30℃。结果姜黄素的进样浓度在0.2114～5.2850μg·ml~(-1)范围内与峰面积积分值呈良好的线性关系,回归方程:Y=1.4044X-0.0780(r=0.9997);平均加样回收率为99.57%,RSD=1.19%(n=6)。结论该方法稳定、简便,可用于消瘀跌打药酒的质量控制。     

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.