复方黄连素片中盐酸小檗碱含量测定

目的：建立测试黄连素片中盐酸小檗碱含量的高效液相方法,并对此方法进行系统的方法学验证,以确保应用该方法测试的结果准确、可靠。方法：采用色谱柱：Agilent TC-C18柱（4．6 mm ×150 mm,5μm,Agilent,美国）,流动相：乙腈－0．05 mol／L磷酸二氢钾溶液（45∶55,含5％的0．05 mol／L庚烷磺酸钠溶液）,检测波长为265 nm。结果：盐酸小檗碱在2．5～80μg／mL范围内线性关系良好,得到线性回归方程为Y＝421 ．5X＋17．32,相关系数为0．9997（n＝6）;低、中、高浓度批内精密度的RSD值分别为0．30％、0．58％、0．30％,批间精密度的RSD为0．80％;重复性RSD为0．27％;低、中、高浓度的加样回收率分别为99．66％、99．88％、99．98％;供试品溶液室温放置8h稳定,RSD为0．41％。结论：本方法测定黄连素片中盐酸小檗碱的含量准确、可靠,操作简单、用时短,可用于黄连素片中盐酸小檗碱的含量测定。     

高效液相色谱法测定羊痫疯丸中盐酸小檗碱含量

目的：建立高效液相色谱法测定羊痫疯丸中盐酸小檗碱含量的方法。方法：采用Agilent ZORBAX SB-C18（250mm×4．6mm,5μm）色谱柱,流动相：乙腈-0．05mol／L磷酸二氢钠溶液（用磷酸调节pH值至3）（25：75）,流速：1．0mL／min,检测波长264nm,柱温40℃。结果：线形范围是：盐酸小檗碱0．0446～1．1150μg,r=0．9998（n=5）。平均回收率为97．25％,RSD为3．14％。结论：方法简便、快速准确,重现性好。可作为羊痫疯丸的质量控制方法。     

盐酸小檗碱对白色念珠菌菌态转换的影响研究

为探讨盐酸小檗碱对白色念珠菌酵母相向菌丝相转换的抑制作用和分子机制,采用微量稀释法测定盐酸小檗碱抑制白色念珠菌生长的MIC值,倒置荧光显微镜观察菌丝动态形成过程;hochest染色法观察不同浓度盐酸小檗碱对菌丝形成的影响;RT-PCR检测在不同浓度盐酸小檗碱作用下白色念珠菌菌丝形成关键基因EFG1、HWP1、ECE1、ALS1表达水平的变化。结果显示,盐酸小檗碱对白色念珠菌的MIC值为32μg/mL,同时白色念珠菌在4 h芽管形成明显,8 h转化为菌丝;hochest染色结果显示:128和32μg/mL的盐酸小檗碱可以通过抑制菌丝的形成以及降低细胞密度,从而达到抑制白色念珠菌发生菌态转换的目的,并且128μg/mL盐酸小檗碱的抑制作用明显优于32μg/mL盐酸小檗碱和4μg/mL氟康唑,而8μg/mL盐酸小檗碱抑制作用不明显;RT-PCR结果表明,128μg/mL盐酸小檗碱可以抑制白色念珠菌4 h干预组菌丝形成关键基因HWP1和ECE1的表达、6 h干预组HWP1、ECE1和ALS1的表达,差异有统计学意义(P0.05);32μg/mL盐酸小檗碱可以抑制白色念珠菌4 h干预组菌丝形成关键基因EFG1和ALS1的表达,6 h干预组EFG1、HWP1和ALS1的表达,差异具有统计学意义(P0.05),但8μg/mL盐酸小檗碱无明显抑制作用。结果表明,盐酸小檗碱可以明显抑制白色念珠菌的菌态转换,其作用机制可能与菌丝形成关键基因EFG1、HWP1、ECE1、ALS1的表达下调相关。     

黄金分割法结合动态设计优选盐黄柏提取工艺

采用黄金分割法结合正交设计以及动态设计对盐黄柏提取工艺参数进行优选。以HLPC法测定盐酸小檗碱、木兰花碱、盐酸小檗红碱、黄柏碱、巴马汀、药根碱得率,黄金分割法初选正交设计时间范围,单因素设计优选溶剂比,基于黄金分割法及单因素设计采用正交设计优选提取溶剂比、提取次数、提取时间。以正交设计优选方案为基础,用动态设计进一步优化盐黄柏的提取工艺参数。结果表明,盐黄柏的优选提取工艺为:提取次数:2次;容积比:1∶25;超声时间:第一次超声60 min,第二次超声20 min;盐酸小檗碱、木兰花碱、盐酸小檗红碱、黄柏碱、巴马汀、药根碱提取率分别为6,51、1,48、0,67、0,62、5,01、73,22 mg/g。因此,黄金分割法结合正交设计、动态设计对盐黄柏提取工艺参数进行优选基本可行,可作为中药提取工艺的筛选方法之一。     

苦玄参药材中苦玄参苷ⅠA和ⅠB的含量分析

采用HPLC法对不同产地的苦玄参药材主成分苦玄参苷ⅠA和ⅠB的含量进行分析,发现苦玄参苷ⅠB含量高于苦玄参苷ⅠA;色谱条件:Waters C18(4.6mmi.d.×250mm,5μm)色谱柱,流动相∶乙睛∶水=36?64(体积比),流速为0.8mL/min,检测波长为264nm。苦玄参苷ⅠA、ⅠB分别在0.05～0.50mg/mL和0.072～0.720mg/mL与峰面积有良好的线性关系。苦玄参苷ⅠA的线性回归方程Y=13658X-92.72(r=0.9993),平均回收率为100.58%(n=5),相对标准偏差(RSD)为1.86%;苦玄参苷ⅠB的线性回归方程Y=5258.9X-41.01(r=0.9994),平均回收率为101.15%(n=5),相对标准偏差(RSD)为1.31%。该研究为制定苦玄参药材质量检测标准提供了简便、快速、准确的方法。     

鳖甲消痔胶囊中中药化学成分的测定

采用薄层色谱法(thin-layer chromatography,TLC)对药方中的土大黄、地榆、槐角和栀子进行定性鉴别,并用高效液相色谱法(high performance liquid chromatography,HPLC)测定胶囊中盐酸小檗碱的含量。结果表明,TLC法可用于土大黄、地榆、槐角和栀子的定性鉴别;盐酸小檗碱对照品在0.1～1.0μg范围内呈线性关系,r=0.999 4;加样回收率为97.80%,RSD为1.40%。本方法结果准确,灵敏度高,重复性好,能够有效地控制鳖甲消痔胶囊的质量。     

蛇伤药酒的质量控制

目的　建立蛇伤药酒的质量控制方法。　方法　用薄层色谱法对蛇伤药酒制剂中黄连、黄柏、大黄进行定性鉴别 ;用紫外分光光度法测定黄连、黄柏中有效成分小檗碱的含量。测定波长为 ( 2 64± 1 ) nm。　结果　定性鉴别色谱特征明显 ,易于区别 ;盐酸小檗碱的含量测定线性范围在 1 .42～ 7.1 0 μg,r=0 .9996,平均回收率为 99.1 4% ,RSD为 1 .3 4%。　结论　该方法可有效的控制蛇伤药酒的质量。     

蜜楝花及果实中吴茱萸碱、吴茱萸次碱及内酯含量积累变化研究

分析测定了不同生长时期蜜楝花及果实中吴茱萸生物碱及吴茱萸内酯含量及其积累变化。色谱条件为:色谱柱为Inertsil ODS-3C_(18)柱(4.6×150 mm,5μm),以乙腈-四氢呋喃-水(41∶1∶58)为流动相,流速1.0 mL/min,检测波长225 nm,柱温30℃。蜜楝中吴茱萸内酯在49.65~248.25μg/mL范围内呈良好的线性关系,Y=1955.4X-5577.3(R~2=0.9996),平均加样回收率102.70%,RSD为3.00%(n=6);吴茱萸碱在8.88~88.80μg/mL范围内呈良好的线性关系,Y=89913X+73191(R~2=0.9990),平均加样回收率103.99%,RSD为2.18%(n=6),吴茱萸次碱在8.25~49.49μg/mL范围内呈良好的线性关系,Y=56127X-51856(R~2=0.9990),平均加样回收率103.50%,RSD为1.48%(n=6)。随着发育阶段的推移,蜜楝花、果实中吴茱萸碱、吴茱萸次碱及吴茱萸内酯的含量逐渐增加,在近成熟的果实中三种成分含量最高。研究结果表明,蜜楝果实中生物碱和吴茱萸内酯的含量丰富,可作为提取制备吴茱萸生物碱及吴茱萸内酯成分的一种植物资源,具有很好的开发利用价值。     

HPLC测定海风藤药材中海风藤酮的含量

建立了HPLC法测定海风藤药材中海风藤酮含量的方法,采用Hypersil ODS2柱(4.6×250mm,5μm),甲醇-水(70∶30)为流动相,流速为1.0mL/min;检测波长280nm;海风藤酮在116~1160μg/mL范围内线性关系良好,回归方程为Y=4561.1X-10927(r=0.9994),平均回收率为99.83%,RSD=1.08%(n=6)。用本方法测得海风藤酮在风藤、石南藤和山蒟中的含量分别为0.25%,0.0057%和0.0014%。     

火焰原子吸收光谱法测定不同品种沙枣中铁、锌的含量

目的:建立干灰化-火焰原子吸收光谱法测定沙枣中铁和锌的含量测定方法。方法:样品的前处理采用干灰化法,含量测定采用空气-乙炔火焰原子吸收光谱法(FAAS)。结果:分别以铁和锌标准溶液的浓度与吸光度进行线性回归:铁标标准曲线回归方程为Y=0.025 82X-0.000 17,相关系数为R2=0.999 8(n=5),线性范围为0.4 0~2.0 0μg/m L,回收率为9 8.6 9%~9 8.9 1%,RSD为0.9 4%~1.0 3%(n=5);锌标准曲线回归方程为Y=0.013 577 X-0.013 67,相关系数为R2=0.999 7(n=5),线性范围为0.40~2.00μg/m L,回收率为98.75~101.95%,RSD为0.86%~1.04%(n=5)。结论 :该方法操作简便、灵敏度高、准确性好、干扰少、环境污染小等特点,是一种比较理想的方法。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).