天胡荽属药用植物的积雪草苷与羟基积雪草苷的含量测定

目的:建立天胡荽属植物的积雪草苷和羟基积雪草苷HPLC含量分析的方法,为开发利用天胡荽属植物药用资源奠定基础。方法:以积雪草苷和羟基积雪草苷为指标成分,采用高效液相色谱法,以Symmetry C18(4.6 mm×250 mm,5μm)为色谱柱;乙腈-水(29∶71,v/v)为流动相;流速0.8 mL/min;柱温30℃;检测波长210 nm,外标法进行测定。结果:积雪草苷的回归方程为:Y=34 958X+154 822 R2=0.999 1(n=8),羟基积雪草苷的回归方程为:Y=114 318X-21 002 R2=0.999 2(n=8),结果表明线性关系与分离度良好,平均加样回收率为99.98%、100.53%,RSD为1.86%、2.31%。结论:该方法稳定性、重复性良好,可做为天胡荽属药用资源的评价方法之一,实验结果为野生与栽培资源的开发与利用奠定了基础。     

积雪苷滴丸的TLC鉴别和HPLC法测定积雪草苷的含量

目的探索建立积雪苷滴丸的鉴别和含量测定的方法。方法TLC法鉴别积雪苷滴丸中积雪草苷和羟基积雪草苷,HPLC法测定积雪草苷的含量。结果TLC法鉴别积雪草苷和羟基积雪草苷结果满意,HPLC法测定积雪草苷的含量,线性范围：y=0.234x＋49.869,r=0.9999,检出线性范围：0.91～45μg,加样回收率为98.9%。结论上述方法准确、专属性强,可作积雪苷滴丸的定性和定量分析方法。     

HPLC法测定积雪草总苷转化产物中积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷的含量

本文建立了积雪草总苷转化产物中积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷含量的测定方法。采用Agilent 1100 Series高效液相色谱仪,Welch Materials,XB-C18(250 mm×4.60 mm,5μm)色谱柱,流动相为乙腈-4 mmol/Lβ-CD溶液(1～15 min:26∶74;15～45 min:28∶72;45～60 min:29∶71,磷酸调节至pH 2.8)梯度洗脱,流速为1.0 mL/min,柱温为30℃,检测波长为204 nm的方法。积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷依次在0.6～6.0μg、1.24～12.4μg和1.34～13.4μg范围内线性关系良好,Y=335.19X-4.7855(r=0.9999)、Y=303.61X-15.208(0.9998)和Y=281.77X-16.357(0.9999);平均加样回收率(n=6)依次为97.59%、100.19%和100.33%,RSD分别为1.70%、0.91%和0.45%。方法学研究结果表明该方法准确、可靠,适用于积雪草总苷转化产物中积雪草酸B单葡萄糖苷、羟基积雪草酸单葡萄糖苷和积雪草酸单葡萄糖苷的含量测定。     

正交试验优化乙醇回流提取积雪草苷的工艺研究

为了优化积雪草中积雪草苷的提取工艺,本研究采用乙醇回流法,以积雪液草苷含量为研究指标,在单因素试验的基础上采用正交试验设计,考察乙醇浓度、液料比、粉碎粒度以及提取时间等因素对提取结果的影响。结果表明,积雪草苷的最佳提取工艺条件为:乙醇浓度70%、液料比10∶1、粉碎粒度140目、提取时间6h,该工艺条件下积雪草苷的提取含量达到8.32mg·g-1。     

RP-HPLC法测定银黄冲剂中黄芩苷在大鼠体内的血药浓度及药代动力学研究

采用高效液相色谱法测定银黄冲剂中黄芩苷在大鼠血浆中的浓度,并研究其药代动力学。色谱柱为D iamonsilTMC18(250 mm×4.6 mm,5μm)柱,流动相:甲醇-磷酸二氢钠缓冲液(pH 2.6),体积比为52:48,检测波长275 nm,流速:1.0 mL/m in。结果血浆中黄芩苷在0.05~20μg/mL范围呈良好的线性关系,r2=0.9997,最低定量限为6 ng/mL。大鼠按1.6 g/kg灌胃银黄冲剂后,黄芩苷的血药浓度时间曲线符合口服吸收有滞后时间的二房室模型,主要药动学参数为t1/2:0.17 h,Vd:2.65 L,K12:5.36/h,K21:0.71/h,Ke:4.25/h,AUC:2.01μg.h/mL。HPLC测定黄芩苷的血药浓度操作便捷,灵敏度高,适用于黄芩苷的药代动力学研究。     

HPLC测定7种龙胆科植物花中龙胆苦苷与獐牙菜苦苷的含量

目的:建立7种龙胆花中龙胆苦苷和獐牙菜苦苷含量测定的HPLC方法。方法:采用微波辅助动态回流法进行提取,色谱条件:Fusion-RP 80 A C18柱(150 mm×4.6 mm,5μm);流动相:甲醇-0.2%磷酸溶液梯度洗脱(0~25 min:15%~30%);流速:1 mL/min;柱温:30℃;检测波长240 nm。结果:7种龙胆花中獐牙菜苦苷和龙胆苦苷的色谱峰与共存组分完全达到基线分离,线性范围分别为0.105~0.945μg(r=0.999 9),0.3~0.7μg(r=0.999 9),平均加样回收率分别为97.8%(RSD=1.02%),98.9%(RSD=1.51%)。结论:所建立的方法测定快速,结果准确可靠。     

HPLC测定葛花中6″-O-木糖鸢尾苷的含量

本文建立了葛花中6″-O-木糖鸢尾苷含量测定的HPLC方法。采用GRACE C18(250 mm×4.6 mm,5μm)色谱柱,流动相为乙腈-水梯度洗脱,流速为0.8 mL/min,紫外检测波长为265 nm,柱温为室温。6″-O-木糖鸢尾苷的峰面积(Y)与浓度(X)在10.33～185.99μg/mL范围内线性关系良好,Y=30731X–216635,r=0.9992(n=7);平均回收率为100.2%,RSD<2%(n=9);测得8批葛花药材中6″-O-木糖鸢尾苷含量为11.08～48.23 mg/g。方法学验证结果表明该法准确、可靠,可用于葛花中主要成分6″-O-木糖鸢尾苷的含量测定。     

HPLC法测定葛花中鸢尾苷的含量

目的：测定8个产地葛花中鸢尾苷的含量,建立葛花中鸢尾苷含量测定的HPLC方法。方法：采用GRACEC18（250mm×4.6mm,5μm）色谱柱,流动相为乙腈-水梯度洗脱,流速为0.8mL/min,紫外检测波长为265nm;柱温为室温。结果：鸢尾苷的峰面积（Y）与浓度（X）在11.8～236.4μg/mL范围内具有良好线性关系,Y=34920X-1156.5,r=0.9995（n=7）;平均加样回收率为103.66%,RSD〈2%（n=9）;测得8批不同产地的葛花药材中鸢尾苷含量在37.00～113.1mg/g。结论：建立了高效液相色谱法测定葛花中鸢尾苷含量的方法,该法准确、可靠,可用于葛花中主要成分鸢尾苷的含量测定;不同产地葛花中均检测到鸢尾苷,但其含量有一定区别。     

HPLC法同时测定草苁蓉中草苁蓉纳拉苷和草苁蓉苷B

为建立高效液相色谱法同时测定草苁蓉干燥全草中草苁蓉纳拉苷和草苁蓉苷B的含量的分析方法,采用色谱柱:Klimail 100-5 C₁₈柱(250 mm×4.6 mm,5μm);流动相:以乙腈为流动相A,以0.5%甲酸水溶液为流动相B,梯度洗脱条件:0~12 min,15%A;12~30 min,15%~20%A;30~40 min,20%~25%A;40~45 min,25%~30%A;45~60 min,30%~100%A;流速:1.0 mL·min^-1;检测波长:260 nm;柱温:30℃;进样量:20μL。得到草苁蓉纳拉苷的线性范围为4.688~150μg·mL^-1(R²=0.999 5);草苁蓉苷B的线性范围为3.438~110μg·mL^-1(R²=0.999 1);平均回收率分别为97.86%、96.55%;RSD分别为1.01、1.23(n=9)。本研究利用高效液相色谱法建立了同时测定草苁蓉全草中草苁蓉纳拉苷和草苁蓉苷B两种组分的方法。方法学的验证结果证明,该方法简便、快捷,重现性好,可以用于草苁蓉中草苁蓉纳拉苷和草苁蓉苷B两种组分的含量测定。     

HPLC梯度洗脱同时测定牛蒡子液体制剂中牛蒡子苷和牛蒡子苷元的含量

目的:建立一种同时测定牛蒡子液体制剂中牛蒡子苷和牛蒡子苷元含量的HPLC梯度洗脱法。方法:采用Dionex Summit高效液相色谱系统,ODS C18柱(4.6mm×250 mm,5μm),乙腈-水为流动相梯度洗脱,流速1.0ml/min,测定波长280nm,柱温30℃下对牛蒡子液体制剂中牛蒡子苷和牛蒡子苷元进行含量测定。结果:牛蒡子苷进样浓度在0.098～0.98mg/ml、牛蒡子苷元进样浓度在0.0304～0.304mg/ml范围内线性关系良好(r=0.9997、r=0.9995),平均回收率分别为100.80%,RSD为1.9%(n=6)和98.6%,RSD为2.3%(n=6)。结论:该方法准确可靠、重现性好,可用于牛蒡子液体制剂的含量测定。     

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.     

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.

     

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.     

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).