In Vivo Metabolism Study of Timosaponin BIII in Rat Using HPLC-QTOF-MS/MS

Timosaponin BIII, as one of the steroid saponins isolated from Anemarrhena asphodeloides Bge., was proved to have many pharmacological activities in recent years and became a natural active compound with good development prospect. In the present study, a simple and rapid method using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry was developed for the determination of the structures of timosaponin BIII and its metabolites in rats after administrating intragastrically at 300 mg kg^?1. By comparing their changes in molecular masses (ΔM), retention times and spectral patterns with those of the parent compound, nine metabolites were detected and identified in urine, and eight in plasma as well as four in brain. It is also indicated that the deglycosylation and oxidation reactions were the main metabolic pathways in the biotransformation of timosaponin BIII in vivo and the structures of the nine metabolites were identified and proposed to be timosaponin BII(M1), the hydroxylated metabolite of TBII(M2), the hydroxylated metabolites of TBIII(M3 and M4), deglycosylation and monooxygenation product of TBIII(M5), the deglycosylation product of TBII(M6), timosaponin AIII(M8), the isomers of timosaponin AIII(M7 and M9).     

In Vivo Metabolism Study of Timosaponin BIII in Rat Using HPLC-QTOF-MS/MS

Timosaponin BIII, as one of the steroid saponins isolated from Anemarrhena asphodeloides Bge., was proved to have many pharmacological activities in recent years and became a natural active compound with good development prospect. In the present study, a simple and rapid method using high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry was developed for the determination of the structures of timosaponin BIII and its metabolites in rats after administrating intragastrically at 300 mg kg⁻¹. By comparing their changes in molecular masses (ΔM), retention times and spectral patterns with those of the parent compound, nine metabolites were detected and identified in urine, and eight in plasma as well as four in brain. It is also indicated that the deglycosylation and oxidation reactions were the main metabolic pathways in the biotransformation of timosaponin BIII in vivo and the structures of the nine metabolites were identified and proposed to be timosaponin BII(M1), the hydroxylated metabolite of TBII(M2), the hydroxylated metabolites of TBIII(M3 and M4), deglycosylation and monooxygenation product of TBIII(M5), the deglycosylation product of TBII(M6), timosaponin AIII(M8), the isomers of timosaponin AIII(M7 and M9).

     

HPLC-ESI-MS/MS识别蓝莓提取物中的花青素和黄酮醇

用高效液相色谱-电喷雾离子化串联质谱联用技术(HPLC-ESI-MS/MS)对蓝莓提取物中的黄酮类物质进行了分析, 可以快速地鉴定其主要成分为花青素和黄酮醇. 结构上的不同导致花青素和黄酮醇在紫外-可见光谱吸收、离子化以及裂解方式上都存在差异. 尽管花青素和黄酮醇在270 nm处都有吸收, 但两者分别在530和372 nm附近有特征吸收. 负离子模式下, 黄酮醇可以生成负离子和自由基负离子, 而正离子型的花青素则几乎不产生质谱信号, 这一显著差异可用以区别花青素和黄酮醇. 花青素与黄酮醇在串联质谱中分别拥有各自的特征产物离子更进一步证实了其结构存在差别. 该研究对于蓝莓提取物的质量分析与控制很有帮助.     

Facile Synthesis and Antitumor Activities of Timosaponin AIII and Its Analogs

An efficient synthesis of timosaponin AIII (TAIII) and five structurally modified analogs via a one-pot sequential glycosylation strategy is described. A partially protected D-galactopyranosyl thioglycoside was employed for regioselective glycosylation to facilitate the target synthesis. The antitumor activities of the synthetic saponins against human epithelial cervical cancer cell (HeLa) were preliminarily evaluated by means of CCK-8 assay. An L-rhamnosyl analog was discovered to display stronger inhibitory activity (IC₅₀ 3.3 μM) than TAIII (IC₅₀ 10.7 μM) to HeLa cell. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file.     

利用HPLC-ESI-MS/MS区分黄芩中黄酮C-苷异构体的研究

采用HPLC-ESI-MS/MS联用技术区分了黄芩中两种互为同分异构体的黄酮C-苷类化合物5,7-OH-6-C-阿拉伯糖-8-C-葡萄糖黄酮和5,7-OH-6-C-葡萄糖-8-C-阿拉伯糖黄酮.阐述了黄酮C-苷类化合物同分异构体的电喷雾串联质谱(ESI-MSⁿ)的特征碎裂规律,证明了[M-H-60]^-,[M-H-90]^-及[M-H-120]^-离子是其特征离子.实验结果表明,对于C-6位五碳糖取代和C-8位六碳糖取代的黄酮C-苷二级串联质谱产生的[M-H-60]^-离子(^0,3₅X),其丰度一般大于50%;而对于C-6位六碳糖取代和C-8位五碳糖取代的黄酮C-苷二级串联质谱产生的[M-H-60]^-离子(^0,3₅X),其丰度一般小于50%.据此可区分两种互为同分异构体的黄酮C-苷类化合物.     

HPLC-ESI-MS/MS检测典型废水与活性污泥中4种大环内酯类抗生素

应用超声波辅助萃取技术,联合固相萃取及高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)技术建立了典型废水和活性污泥中4种大环内酯类抗生素(MLs)的高灵敏分析方法。水样经Oasis HLB萃取小柱富集、净化后以甲醇洗脱;活性污泥样品以乙腈-磷酸盐缓冲溶液为溶剂超声萃取、富集、净化。采用HPLC-ESI-MS/MS进行定量分析;流动相为乙腈-乙酸铵水溶液,采用电喷雾正电离源和选择性反应监测模式进行检测。结果表明,4种抗生素的线性范围为0.1～100μg·L-1,相关系数均大于0.99,方法检出限为0.002～0.019 pg,废水和活性污泥样品中MLs的平均回收率分别为70.2%～90.6%和75.6%～88.7%,方法检出限分别为0.013～0.025 ng·L-1和0.09～0.22 ng.g-1。将建立的方法应用于新疆石河子市可能的抗生素污染源典型废水和活性污泥样品中4种MLs的检测,结果表明,MLs普遍存在于各废水(未检出～308.23ng·L-1)和活性污泥(未检出～120.46 ng.g-1)样品中。     

Investigation of antibacterial phytochemicals in the bark and leaves of Ficus coronata by high-performance liquid chromatography-electrospray ionization-ion trap mass spectrometry (HPLC-ESI-MS(n) ) and ESI-MS(n)

The ethyl acetate extracts of the bark and leaves of Ficus coronata were separated by column chromatography and the resulting fractions tested for their bioactivity toward methicillin-resistant-Staphylococcus aureus (MRSA) and M. luteus. The bioactive column chromatography fractions were further separated by preparative thin layer chromatography (TLC) and the resulting bands investigated by high-performance liquid chromatography-electrospray ionization-ion trap mass spectrometry (HPLC-ESI-MS(n) ) and ESI-MS(n) . The resulting retention times, molecular masses, their fragmentation patterns, and the chemnet database (www.chemnetbase.com) were then used in the dereplication process by structural elucidation of some of the compounds when compared with known structures of natural origin. Some molecular masses and the corresponding fragmentations were found that did not correlate with any known compounds thus revealing potentially novel natural products that could be investigated on a larger scale and could ultimately find application as new drugs against MRSA and other multidrug-resistant microorganisms. Structures are also proposed for known compounds that have not been previously reported for F. coronata.     

用密度泛函理论研究ZrnB（n=1-13）团簇的结构及性质

利用密度泛函理论,得到了ZrnB(n=1-13)团簇的基态结构,计算并讨论了团簇能量的二阶差分和离解能.结果表明,n=2,5,12时,相应团簇较稳定,特别是Zr5B团簇的稳定性最高.同时分析了ZrnB团簇的电子性质及磁性,结果显示能隙随n值的增大出现奇偶振荡趋势,特别是ZrM12B团簇的能隙只有0.015 eV,表明该团簇已具有金属性.电倚转移随n值增大,整体呈增大趋势,除了二聚体ZrB,电荷由B原子转移到Zr原子.利用Mulliken布居分析得到二聚体ZrB(5.000 μB)和团簇Zr4B(3.000 μB)的磁矩较大,ZrnB团簇中总磁矩主要来自Zr原子的4d轨道.     

Identification and Simultaneous Determination of Mangiferin,Neomangiferin, Timosaponin A-III,and Timosaponin C in Rhizoma Anemarrhenae by Rapid Resolution Liquid Chromatography Coupled with Triple Quadrupole Mass Spectrometry

A new and rapid method was developed for simultaneous determination of mangiferin, neomangiferin, timosaponin A-III, and C in Rhizoma Anemarrhenae using rapid resolution liquid chromatography coupled with triple quadrupole mass spectrometry. The analysis was performed on an Eclipse Plus C₁₈ column (I.D. 4.6 × 100 mm, 3.5 μm). Electrospray ionization–tandem interface in the negative mode was employed prior to mass spectrometric detection. Quantitation was based on multiple reaction monitoring (MRM) for determination. Limits of detection (LODs) ranged from 0.7 to 3 pg. The average recoveries ranged from 98.16 to 100.7% with RSDs ≤ 2.03%. The established method was validated, sensitive, and reliable.     

手性毛细管色谱法测定人尿中美芬妥英对映体的含量及其在代谢分型中的应用

采用手性毛细管色谱柱和ＦＩＤ检测器建立了人尿中美芬妥英（ＭＰ）对映体的定量分析方法。尿样用二氯乙烷提取，用酸、碱洗涤得以纯化，测得各对映体的最低检测限为６０μｇ／Ｌ。在１１５～６９０μｇ／Ｌ浓度范围内，标准曲线呈良好的线性关系，ｒ＞０．９９，日内、日间精密度ＲＳＤ＜６．５％，Ｓ－ＭＰ的平均回收率为７４．４１％，Ｒ－ＭＰ的平均回收率为７３．７８％。并以ＭＰ为探针药物，对３２名志愿者的尿样进行了ＭＰ氧化代谢分型研究。     

Fast and Sensitive HPLC-ESI-MS/MS Method for Etoricoxib Quantification in Human Plasma and Application to Bioequivalence Study

Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation. The objective of the current study was to develop a sensitive, fast and high-throughput HPLC-ESI-MS/MS method to measure etoricoxib levels in human plasma using a one-step methanol protein precipitation technique. A tandem mass spectrometer equipped with an electrospray ionization (ESI) source operated in a positive mode and multiple reaction monitoring (MRM) were used for data collection. The quantitative MRM transition ions were m/z 359.15 > 279.10 and m/z 363.10 > 282.10 for etoricoxib and IS. The linear range was from 10.00 to 4000.39 ng/mL and the validation parameters were within the acceptance limits of the European Medicine Agency (EMA) and Food and Drug Analysis (FDA) guidelines. The present method was sensitive (10.00 ng/mL with S/N > 40), simple, selective (K prime > 2), and fast (short run time of 2 min), with negligible matrix effect and consistent recovery, suitable for high throughput analysis. The method was used to quantitate etoricoxib plasma concentrations in a bioequivalence study of two 120 mg etoricoxib formulations. Incurred sample reanalysis results further supported that the method was robust and reproducible.     

线粒体体外代谢热动力学研究

线粒体是细胞重要的细胞器之一，有细胞的“能源工厂”之称．因为线粒体内有许多酶，是特殊的酶催化氧化反应的场所山；所有动、植物细胞的线粒体都能通过各种营养物的氧化而产生“富能”物质ATP．采用一定的技术可将线粒体从细胞中分离出来，分离出来的线粒体中的酶系统还有一定的活性，而且线粒体内也有一定的营养物质，这样酶系统就能利用这些营养物进行代谢，从而释放出一定的能量．我们用微量热法对两种鱼肝脏线粒体进行了测量，发现线粒体代谢过程分四个阶段：停滞期、活性恢复期、稳定期、活性衰减期．在活性恢复期和活性衰减期，…     

用密度泛函理论研究ZrnB(n=1-13)团簇的结构及性质

利用密度泛函理论, 得到了ZrnB(n=1-13)团簇的基态结构, 计算并讨论了团簇能量的二阶差分和离解能. 结果表明, n=2, 5, 12时, 相应团簇较稳定, 特别是Zr5B团簇的稳定性最高. 同时分析了ZrnB团簇的电子性质及磁性, 结果显示能隙随n值的增大出现奇偶振荡趋势, 特别是Zr12B团簇的能隙只有0.015 eV, 表明该团簇已具有金属性. 电荷转移随n值增大, 整体呈增大趋势, 除了二聚体ZrB, 电荷由B原子转移到Zr原子. 利用Mulliken布居分析得到二聚体ZrB(5.000 μB)和团簇Zr4B(3.000 μB)的磁矩较大, ZrnB团簇中总磁矩主要来自Zr原子的4d轨道.     

Theoretical Study of Structure and Stability of B n O and B n O2 Clusters

The structures and stabilities of B _n O and B _n O₂ clusters with n ≤ 6 are studied systematically by using density-functional theory. The lowest-energy structures of B _n O clusters favor two-dimensional, and can be obtained from B _n or B _n−1O. For B _n O₂, unexpectedly, all of the most stable B _n O₂ clusters but B₆O₂ are linear. Furthermore, in B _n O₂ clusters, the longer the distance between two O atoms, the more stable the structure. To investigate the relative stability of considered clusters, binding energies per atom, reaction energies, and fragmentation energies are also calculated and discussed.     

The Influence of the Framework: An Anion‐Binding Study Using Fused [n]Polynorbornanes

A series of bis‐thiourea‐functionalized [n]polynorbornane hosts ( 1 – 6 ) with increasing size were synthesized and their anion‐binding properties were evaluated by using ¹H NMR spectroscopic titration and Job’s plot analysis. The larger bis‐thiourea‐[3]polynorbornane scaffolds 4 and 5 bound acetate in a 1:1 (cooperative) arrangement, whereas the corresponding smaller norbornane host 2 , identical in preorganization, bound acetate in a 1:2 (independent) arrangement. In contrast, the size of the framework had no influence on the binding of dihydrogenphosphate. These results clearly highlight the subtle influence that the framework itself can have on host–guest interactions.     

An Investigation of the Metabolism of Amitriptyline Using High Performance Liquid Chromatography

Abstract

A systematic study of the metabolism of the antidepressant amitriptyline was conducted using an inbred strain of rats. Variables affecting rat liver metabolism in vitro that were examined include age of the rat, the substrate concentration, and pH. A liquid-liquid extraction with hexane-butanol and back extraction into phosphoric acid was developed to provide efficient extraction for the wide range of polarity exhibited by amitriptyline and seven metabolites (amitriptyline-N-oxide, cis and trans isomers of 10-hydroxy-amitriptyline, cis and trans isomers of 10-hydroxynortriptyline, nortriptyline, and desmethylnortriptyline). HPLC was performed with 5 μm C-8 reversed phase column and a methanol/sodium phosphate buffer/amine modifier mobile phase.     

Metabolism Studies of Polycyclic Mutagens and Carcinogens Using Liquid Chromatography with Ultraviolet and Electrochemical Detection

Abstract

HPLC ultraviolet (UV) and electrochemical (EC) detectors connected in series were used to classify the metabolites of naphthalene, anthracene, acridine, and phenanthridine into phenolic and nonphenolic categories. This method of classification is based on comparison of the relatively high response of the EC detector to electroactive species such as phenols to the more nonselective response of the UV detector. The method is generally useful for many biologically active substances.     

Simultaneous determination and pharmacokinetic study of metformin and rosiglitazone in human plasma by HPLC-ESI-MS

A fast, sensitive and specific high-performance liquid chromatography tandem mass spectrometry method was developed for simultaneous determination of metformin and rosiglitazone in human plasma. With phenformin as an internal standard, the analysis was carried out on a C(18) column (50 mm × 2.1 mm, 3.5 μm) using a mobile phase consisting of acetonitrile-10 mM ammonium acetate (20:80, v/v). The detection was performed by tandem mass spectrometry via electrospray ionization. Linear calibration curves were obtained in the concentration of 1.054-263.5 ng/mL for rosiglitazone and 4.040-5050 ng/mL for metformin. The method was applicable to clinical pharmacokinetic study of metformin and rosiglitazone in healthy volunteers following oral administration.