液相色谱-串联质谱法同时测定大鼠血浆中阿霉素和塞来昔布

目的:建立同时测定大鼠血浆中阿霉素和塞来昔布的液相色谱-串联质谱(LC/MS/MS)方法,研究这两种药物联合应用的药代动力学.方法:大鼠尾静脉注射阿霉素和塞来昔布,眼眶取血并抗凝,离心分离血浆,采用乙酸乙酯提取血浆中的阿霉素和塞来昔布,N2吹干乙酸乙酯,残留物用50μL甲醇溶解,取20μL用于LC/MS/MS分析.结果:用LC/MS/MS法检测大鼠血浆中阿霉素和塞来昔布的线性范围为1-800ng/mL,日内、日间精密度(RSD)均小于15%,检测血浆低、中、高三个浓度(8、50、500ng/mL)阿霉素的回收率分别为101.2%、95.1%和91.4%,检测血浆低、中、高三个浓度(8、50、500ng/mL)塞来昔布的回收率分别为105.6%、106.8%和93.7%.大鼠尾静脉注射5.8mg/kg阿霉素和3.8mg/kg塞来昔布的半衰期分别为2.3 h和3.6h,曲线下面积分别为670 ng·h·mL-1和1480ng·h·mL-1.结论:建立的方法灵敏、准确、快速,适甩于阿霉素和塞来昔布的药代动力学研究.     

LC-MS/MS 法测定人血浆中伊伐布雷定浓度及药动学

目的:建立人血浆中伊伐布雷定的液相色谱-质谱-质谱联用测定方法,研究健康人体药代动力学.方法:以地西泮为内标物,采用液相色谱-质谱-质谱联用法,电喷雾电离源选择性正离子峰检测.测30名健康志愿者单剂量口服盐酸伊伐布雷定片的体内血药浓度,获得药动学参数.结果:伊伐布雷定在0.101-101 ng·mL-1浓度范围内呈良好的线性关系(r=0.998),最低检测浓度为0.101 ng·mL-1.高、中、低浓度的方法提取回收率分别为93.2%、86.6%、87.5%,日内、日间精密度RSD均小于15%.结论:LC-MS/MS方法灵敏度高,专属性强,准确,简便,适用于盐酸伊伐布雷定片的人体药代动力学研究.     

黄芪甲苷在大鼠体内的药代动力学和组织分布研究

建立了固相萃取-HPLC-MS测定大鼠血浆中黄芪甲苷含量的方法,并对其在大鼠体内的药代动力学和组织分布进行了研究。分别以1,2,4 mg/kg的剂量对大鼠静脉给药,给药后2,10,20,30,60 min和1.5,2,3,4,6,8 h采集血样,同时以2 mg/kg的剂量对大鼠静脉给药,给药后20,60,240 min采集各组织,测定血浆样品和组织样品中的黄芪甲苷浓度。血药浓度-时间曲线按二室模型拟合最佳,t1/2(α)分别为12.36,7.05,15.98 min,t1/2(β)分别为69.14,73.28,95.24 min,AUC分别为277.36,415.36,623.15μg.min/mL,AUC与剂量的线性方程为y=113.64x 173.47(r=0.997),表明黄芪甲苷在大鼠体内呈线性消除。组织分布研究表明黄芪甲苷在体内分布较广。     

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。     

LC-MS/MS法测定人血浆中伊伐布雷定浓度及药动学

目的：建立人血浆中伊伐布雷定的液相色谱-质谱-质谱联用测定方法,研究健康人体药代动力学。方法：以地西泮为内标物,采用液相色谱-质谱-质谱联用法,电喷雾电离源选择性正离子峰检测。测30名健康志愿者单剂量口服盐酸伊伐布雷定片的体内血药浓度,获得药动学参数。结果：伊伐布雷定在0.101-101 ng·mL-1浓度范围内呈良好的线性关系（r=0.998）,最低检测浓度为0.101 ng·mL-1。高、中、低浓度的方法提取回收率分别为93.2%、86.6%、87.5%,日内、日间精密度RSD均小于15%。结论：LC-MS/MS方法灵敏度高,专属性强,准确,简便,适用于盐酸伊伐布雷定片的人体药代动力学研究。     

LC-MS/MS法同时测定大鼠血浆中地榆皂苷Ⅰ和地榆皂苷Ⅱ的血药浓度及其药代动力学

采用液相色谱-串联质谱法(LC-MS/MS)同时测定大鼠血浆中的地榆皂苷Ⅰ和地榆皂苷Ⅱ,并在此基础上研究这两种活性物质在大鼠体内的药代动力学。样品前处理采用沉淀蛋白法,选用Ultimate XB-C8色谱柱(100 mm×2.1 mm,3μm,Welch,USA),采用Sciex 4000 Q-TRAP型三重四级杆串联质谱,电喷雾(ESI)源,多级反应监测(MRM)负离子模式。血浆中地榆皂苷Ⅰ和地榆皂苷Ⅱ的标准曲线线性范围均为1～2 000 ng/mL(相关系数R0.995),本方法灵敏、快速且稳定。大鼠口服给予地榆标准品后,吸收较快,绝对生物利用度(F_(abs))较小。所建立的方法可准确、快速、灵敏地检测大鼠血浆中地榆皂苷Ⅰ和地榆皂苷Ⅱ的血药浓度,适用于临床前的药代动力学研究。     

UPLC-Triple TOF-MS方法鉴定野漆树苷在大鼠体内的代谢物

目的:分析野漆树苷在大鼠体内的代谢产物结构。方法:大鼠灌胃给予野漆树苷96 mg/kg后,收集0~24h尿液及粪便样品,应用超高效液相色谱-串联四极杆飞行时间质谱(UPLC-Triple TOF-MS)技术分析野漆树苷在大鼠体内的代谢产物。结果:共检测到了除原型药的4个代谢产物。经过对野漆树苷可能代谢产物的母离子和碎片离子的准确分子量及裂解规律的解析,并结合黄酮类化合物的可能代谢途径,推断出了这些代谢产物的结构。结论:上述实验结果将为血浆代谢产物的寻找提供靶标,为野漆树苷体内物质基础的确立以及体内代谢途径和代谢机制的研究提供重要的参考。     

万氏牛黄清心缓释胶囊在比格犬体内药动学研究

目的:研究比格犬单剂量交叉口服万氏牛黄清心缓释胶囊和市售普通丸给药的药动学.方法:采用高效液相色谱法测定10只比格犬单剂量口服万氏牛黄清心pH-依赖型梯度释药胶囊和市售丸后血浆中盐酸小檗碱的血药浓度.血浆样品采用碱化后乙醚萃取浓缩方法制备.以青藤碱为内标物质,流动相采用乙腈-0.1 mol·L-1磷酸二氢钾溶液-磷酸(30:70:0.01),检测波长为262nm,流速为1.0mL·min-1.结果:血浆中内源性物质对盐酸小檗碱及青藤碱的测定无干扰;最低检出限为1.25ng·mL-1;盐酸小檗碱在1.25～250ng·mL-1浓度范围内线性关系良好,r=0.9990;绝对回收率为82.94%～88.36%,方法回收率为89.28%～92.29%;日内精密度RSD≤4.87%、日间精密度RSD≤7.03%.缓释胶囊和普通丸药动学参数AUC0∞分别为668.02和809.95 h·ng·ml-1,MRT分别为5.27和4.34h,缓释胶囊相对于普通丸的生物利用度为84.6%.结论:建立的测定方法处理简单,无干扰,灵敏度高,适合测定中药缓释制剂的药物动力学研究.万氏牛黄清心缓释胶囊具有明显的缓释作用,药物在体内呈梯度释放.     

LC-MS/MS方法测定比格犬血浆中沙芬酰胺及其代谢物

建立液相色谱-质谱联用/质谱(LC-MS/MS)测定比格犬血浆中沙芬酰胺异构体及其代谢物浓度的方法,在此基础上对沙芬酰胺异构体及其代谢物在比格犬体内的药代动力学进行研究。色谱检测条件方法一为用AS-RH手性柱测定沙芬酰胺异构体;方法二为用XB-C18分析柱测定沙芬酰胺代谢物。质谱条件离子源为APCI源,离子化方式为正离子模式,喷雾电压5 200 V,加热毛细管温度550℃,雾化气(N2)流速75.8 KPa,气帘气(N2)75.8KPa,碰撞气(N2)55.16 KPa,扫描方式为多反应监测(MRM)。建立的LC-MS/MS方法线性范围左旋沙芬酰胺为10~2 000 ng/m L(r=0.999 4),右旋沙芬酰胺为10~2 000 ng/m L(r=0.997 6),沙芬酰胺代谢物为10~1 000 ng/m L(r=0.994 1)。本方法灵敏,快速且稳定,适用于沙芬酰胺异构体及其代谢物药代动力学研究。     

小型猪血浆中二丙酸倍他米松及其代谢物倍他米松的LC-MS/MS 同时测定方法的建立及在药动学研究中的应用

目的：建立同时测定小型猪血浆中二丙酸倍他米松及其代谢物倍他米松的LC-MS/MS 法,并研究小型猪皮肤外用二丙酸倍他米松乳膏后,二丙酸倍他米松及倍他米松的药动学特征。方法：血浆样品经酸化后以乙醚- 环己烷（4 ∶ 1）提取,LC-MS/MS 分析,以Hedera ODS-2（150 mm×2.1 mm,5 μm）为分析柱,流动相为5 mmol?L-1 醋酸铵水溶液（含0.1% 乙酸）– 甲醇,梯度洗脱。二丙酸倍他米松、倍他米松及内标布地奈德的监测离子对分别为m /z 563.2（[M+CH3COO]-）→ 483.1、m /z 451.2（[M+CH3COO]-）→ 361.0 和m /z 489.3（[M+CH3COO]-）→ 357.1。对小型猪外用二丙酸倍他米松乳膏后其血浆中二丙酸倍他米松及代谢物倍他米松的浓度进行测定,并计算主要药动学参数。结果：二丙酸倍他米松血药浓度在26.85~644.4 ng?L-1 范围内线性关系良好,倍他米松血药浓度在10.62~637.2 ng?L-1 范围内线性关系良好。结论：本方法专属性强、简便、灵敏,可用于血浆样本中二丙酸倍他米松及其代谢物倍他米松的测定及药动学研究。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.