Cu-BTC Derived Mesoporous CuS Nanomaterial as Nanozyme for Colorimetric Detection of Glutathione.

In this paper, Cu-BTC derived mesoporous CuS nanomaterial (m-CuS) was synthesized via a two-step process involving carbonization and sulfidation of Cu-BTC for colorimetric glutathione detection. The Cu-BTC was constructed by 1,3,5-benzenetri-carboxylic acid (H3BTC) and Cu2+ ions. The obtained m-CuS showed a large specific surface area (55.751 m2/g), pore volume (0.153 cm3/g), and pore diameter (15.380 nm). In addition, the synthesized m-CuS exhibited high peroxidase-like activity and could catalyze oxidation of the colorless substrate 3,3',5,5'-tetramethylbenzidine to a blue product. Peroxidase-like activity mechanism studies using terephthalic acid as a fluorescent probe proved that m-CuS assists H2O2 decomposition to reactive oxygen species, which are responsible for TMB oxidation. However, the catalytic activity of m-CuS for the oxidation of TMB by H2O2 could be potently inhibited in the presence of glutathione. Based on this phenomenon, the colorimetric detection of glutathione was demonstrated with good selectivity and high sensitivity. The linear range was 1-20 µM and 20-300 µM with a detection limit of 0.1 µM. The m-CuS showing good stability and robust peroxidase catalytic activity was applied for the detection of glutathione in human urine samples.

Dispersive solid phase extraction based on cross-linked hydroxypropyl ß-cyclodextrin polymers for simultaneous enantiomeric determination of three chiral triazole fungicides in water.

An efficient method is presented for simultaneous enantioselective determination of three chiral triazole fungicides (namely paclobutrazol, hexaconazole, and diniconazole) in water samples by DSPE-HPLC-UV. The perfect chiral separation of the enantiomers was achieved on a Chiralpak IH column within 15 min. In order to adsorb and enrich the analytes from water matrices, a cross-linked hydroxypropyl ß-cyclodextrin polymer was synthesized. The prepared material exhibited good adsorption capacity, which was assessed by adsorption kinetic and adsorption thermodynamic experiments. One-variable-at-a-time and the response surface methodology were used to optimize the extraction parameters. Under the optimum sample preparation conditions, good linearity (2.0 ~ 800 µg L-1, R2 ≥ 0.9978), detection limits (0.6 to 1.0 µg L-1), quantitation limits (2.0 to 3.2 µg L-1), recoveries (86.7 ~ 105.8%), and the relative standard deviation (intra-day RSD ≤ 3.7%, inter-day RSD ≤ 5.1%) were obtained, satisfying the requirements of pesticides residues determination. These results demonstrated that the proposed method was applicable for routine determination of chiral triazole fungicide residues in water samples.

Advances in Extraction, Purification, and Analysis Techniques of the Main Components of Kudzu Root: A Comprehensive Review.

Kudzu root (Pueraria lobate (Willd.) Ohwi, KR) is an edible plant with rich nutritional and medicinal values. Over the past few decades, an ample variety of biological effects of Pueraria isoflavone have been evaluated. Evidence has shown that Pueraria isoflavone can play an active role in antioxidant, anti-inflammatory, anti-cancer, neuroprotection, and cardiovascular protection. Over 50 isoflavones in kudzu root have been identified, including puerarin, daidzein, daidzin, 3'-hydroxy puerarin, and genistein, each with unambiguous structures. However, the application of these isoflavones in the development of functional food and health food still depends on the extraction, purification and identification technology of Pueraria isoflavone. In recent years, many green and novel extraction, purification, and identification techniques have been developed for the preparation of Pueraria isoflavone. This review provides an updated overview of these techniques, specifically for isoflavones in KR since 2018, and also discusses and compares the advantages and disadvantages of these techniques in depth. The intention is to provide a research basis for the green and efficient extraction, purification, and identification of Pueraria isoflavone and offers investigators a valuable reference for future studies on the KR.

The Research Progress of Extraction, Purification and Analysis Methods of Phenolic Compounds from Blueberry: A Comprehensive Review.

Blueberry is the source of a variety of bioactive substances, including phenolic compounds, such as anthocyanins, pterostilbene, phenolic acids, etc. Several studies have revealed that polyphenols in blueberry have important bioactivities in maintaining health, such as antioxidant and anti-tumor activities, immune regulation, the prevention of chronic diseases, etc. Therefore, these phenolic compounds in blueberries have been widely used in the field of healthcare, and the extraction, isolation, and purification of phenolic compounds are the prerequisites for their utilization. It is imperative to systematically review the research progress and prospects of phenolic compounds present in blueberries. Herein, the latest progress in the extraction, purification, and analysis of phenolic compounds from blueberries is reviewed, which can in turn provide a foundation for further research and usage of blueberries.

Using UPLC-QTOF/MS and multivariate analysis to explore the mechanism of Bletilla Striata improving PM2.5-induced lung impairment.

Exposure to fine particulate matter (PM2.5) is closely related to lung diseases and has become more and more harmful to public health. The traditional Chinese medicine of Bletilla Striata has the effect of clearing and nourishing the lungs in clinics. The purpose of the study is using metabolomics methods to explore the mechanism of PM2.5-induced lung injury and Bletilla Striata's therapeutic effect. In this article, we used an Ultra Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (UPLC-QTOF/MS) method to identify the potential biomarkers. The results showed that there were 18 differential metabolites in the plasma and urine of rats with PM2.5-induced lung injury, involving the glycerophospholipid metabolism pathway, the tryptophan metabolism pathway, and the purine metabolism pathway, etc. After the administration, Bletilla Striata changed the levels of 21 metabolites, and partly corrected the changes in the level of metabolites caused by PM2.5. The results indicated that Bletilla Striata could exert a good therapeutic effect by reversing the levels of some biomarkers in the rats with PM2.5-induced lung impairment.

Development of a sensitive ultra high performance liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of nine active compounds in rat plasma and its application to a pharmacokinetic study after administration of Viscum coloratum extracts.

A simple, specific, and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was developed and validated for the simultaneous quantification of nine compounds including a new compound, rhamnazin-3-Ο-ß-D-(6″-ß-hydroxy-ß-methyglutaryl)-ß-D-glucoside-4'-Ο-ß-D-glucoside, in rat plasma using baicalin as an internal standard. The plasma samples were pretreated and extracted by protein precipitation with 0.2% formic acid in acetonitrile. The analytes were separated on a Thermo Syncronis C18 column by gradient elution with a mobile phase consisting of acetonitrile and 0.1% aqueous formic acid at a flow rate of 0.25 mL/min. The detection of the analytes was performed on an electrospray ionization interface operating in positive-ion and multiple reaction monitoring acquisition modes. The calibration curves of these analytes showed good linearity (r > 0.99) within the test ranges. The lower limit of quantification ranged from 0.4 to 20.1 ng/mL for the analytes. The intra- and interday precision and accuracy were all within ±15%, and the recoveries were higher than 80.0%. The validated method was successfully applied to a pharmacokinetic study of the nine flavonoids after administration of the Viscum coloratum extracts by intravenous injection.

Differential pharmacokinetics and the brain distribution of morphine and ephedrine constitutional isomers in rats after oral administration with Keke capsule using rapid-resolution LC-MS/MS.

Opioid and ephedra alkaloids known as the active ingredients for Keke capsule, which is used to treat coughs and bronchial asthma, could have potential adverse effects on the central nervous system. Therefore, an efficient, sensitive rapid-resolution LC-MS/MS method for the simultaneous determination of morphine, ephedrine, and pseudoephedrine in rat plasma and brain tissue homogenate has been developed. The method was validated in the plasma and brain tissue samples, showed good linearity over a wide concentration range (r(2) > 0.99). The intra- and interday assay variability was less than 15% for all analytes, and the accuracy was between -8.8 and 5.7%. The study provided the pharmacokinetics profiles and the brain regional distribution of the three active alkaloids after oral administration of Keke capsule. The results also indicated that significant difference in pharmacokinetics parameters of the epimers was observed between ephedrine and pseudoephedrine.

Metabolism of TM-2, a potential antitumor drug, in rats by using LC-MS.

TM-2 (13-(N-Boc-3-i-butylisoserinoyl-4,10-ß-diacetoxy-2-α-benzoyloxy-5-ß-20-epoxy-1,13-α-dihydroxy-9-oxo-19-norcyclopropa[g]tax-11-ene) is a novel semisynthetic taxane derivative. Our previous study suggested that TM-2 is a promising antitumor analogue. In this paper, the metabolism of TM-2 was investigated in rats following intravenous administration. Two different types of mass spectrometry-hybrid linear trap quadrupole orbitrap (LTQ-Orbitrap) mass spectrometry and triple-quadrupole tandem (QQQ) mass spectrometry-were employed to acquire structural information of TM-2 metabolites. A total of 17 components were identified as the metabolites of TM-2 in bile, feces, and urine samples. Accurate mass measurement using LC-LTQ-Orbitrap-MS was used to determine the accurate mass data and elemental composition of metabolites thereby confirming the proposed structures of the metabolites. The metabolites proposed were mainly oxidates of TM-2, including methoxy, hydroxyl, dihydroxy, and trihydroxyl analogues. The major metabolic pathway of TM-2 was the hydroxylation of the taxane ring or the lateral chain. These important metabolic data serve as a useful resource to support further research of TM-2.

Arsenic Activates the NLRP3 Inflammasome and Disturbs the Th1/Th2/Th17/Treg Balance in the Hippocampus in Mice.

Arsenic exerts neurotoxicity and immunomodulatory effects. Studies have shown that the nervous system is not considered to be an immune-privileged site. However, the effect of arsenic-induced neuroimmune toxicity has rarely been reported. We aimed to investigate the toxic effects of arsenic on the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and the Th1/Th2/Th17/Treg balance in the brain tissue of mice. Mice were exposed to NaAsO2 (0, 2.5, 5, and 10 mg/kg) for 24 h. Our results showed that 10 mg/kg arsenic exposure significantly decreased brain and hippocampal indices (p < 0.05). The mRNA and protein levels of the blood‒brain barrier (BBB) tight junction protein occludin were decreased in the 5 and 10 mg/kg arsenic-treated groups. Compared with those in the control group, NLRP3 protein levels in 10 mg/kg arsenic-treated mice, caspase-1 protein levels in 2.5, 5, and 10 mg/kg arsenic-treated mice, and IL-1ß protein levels in 5 and 10 mg/kg arsenic-treated mice were increased in the hippocampus (p < 0.05). In addition, arsenic induced a hippocampal inflammatory response by upregulating the mRNA levels of the proinflammatory factors IL-6 and TNF-α and downregulating the mRNA level of the anti-inflammatory factor IL-10. Moreover, arsenic decreased the mRNA levels of the Th1 and Th2 transcription factors T-bet and GATA3 and the cytokines IFN-γ and IL-4 and increased the mRNA levels of the Th17 transcription factor RORγt and the cytokine IL-22 (p < 0.05). Collectively, our study demonstrated that arsenic could induce immune-inflammatory responses by regulating the NLRP3 inflammasome and CD4+ T lymphocyte differentiation. These results provide a novel strategy to block the arsenic-induced impairment of neuroimmune responses.

Sedimentary and diagenetic characteristics of the Z21 field in the Huizhou depression, Pearl River Mouth basin, South China Sea.

The Huizhou Depression in the Pearl River Mouth basin has prospective hydrocarbon potential, with Miocene sandstones as its main oil and gas-bearing reservoir. The sandstones in Miocene formation of the Z21 offshore oil-gas field composed of medium-grained, moderately sorted subarkose and lithic arkose. In this study, a total of six depositional lithofacies, namely Massive fine- to medium-grained sandstone (Sm), ripple cross-laminated fine-grained sandstone (Sr), parallel-laminated siltstone and claystone (Fl), lenticular siltstone (Sl), parallel-bedded fine-grained sandstone (Sp), wavy laminated siltstone (Sw), and two depositional systems, namely nearshore sand bar (SB) and sand sheet (SS) were identified based on core observations and seismic study. Distributions of the porosity (13.9%) and permeability (35.8 mD) reveal that the Miocene sandstones have characteristics of low porosity and low permeability, with high heterogeneity. The sedimentary system, primary texture and diagenesis jointly control the reservoir quality. Sandstones with sand bars as well coarse-grained tend to exhibit a higher quality. Mechanical compaction and calcite (average 6.81%) cementation are the major determinants to reductions in porosity and permeability. The total clay minerals (average 5.27%) generally lead to reduction of porosity, whereas chlorite coatings and illite within a certain content range may enhance the preservation of porosity in eodiagenesis. Dissolution of feldspar and debris contribute significantly to improving the reservoir quality.

Metabolomics-based comparative analysis of the effects of host and environment on Viscum coloratum metabolites and antioxidative activities.

Viscum coloratum (Kom.) Nakai is a well-known medicinal hemiparasite widely distributed in Asia. The synthesis and accumulation of its metabolites are affected by both environmental factors and the host plants, while the latter of which is usually overlooked. The purpose of this study was to comprehensively evaluate the effects of host and habitat on the metabolites in V. coloratum through multiple chemical and biological approaches. The metabolite profile of V. coloratum harvested from three different host plants in two habitats were determined by multiple chemical methods including high-performance liquid chromatography-ultraviolet (HPLC-UV), gas chromatography-flame ionization detector (GC-FID) and ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF/MS). The differences in antioxidant efficacy of V. coloratum were determined based on multiple in vitro models. The multivariate statistical analysis and data fusion strategy were applied to analyze the differences in metabolite profile and antioxidant activity of V. coloratum. Results indicated that the metabolite profile obtained by various chemical approaches was simultaneously affected by host and environment factors, and the environment plays a key role. Meanwhile, three main differential metabolites between two environment groups were identified. The results of antioxidant assay indicated that the environment has greater effects on the biological activity of V. coloratum than the host. Therefore, we conclude that the integration of various chemical and biological approaches combined with multivariate statistical and data fusion analysis, which can determine the influences of host plant and habitat on the metabolites, is a powerful strategy to control the quality of semi-parasitic herbal medicine.

Metabolomics analysis of Semen Cuscutae protection of kidney deficient model rats using ultra high-performance liquid chromatography-quadrupole time-of-flight Mass Spectrometry.

The traditional Chinese medicine syndrome "Kidney yang deficiency" is a kind of chronic kidney disease. With the development of society, the incidence of chronic kidney disease is increasing year by year, which also brings great economic pressure to people. Semen Cuscutae is an important traditional Chinese medicine to tonify liver and kidney, mainly used to tonify deficiency of liver and kidney, spleen and kidney deficiency and diarrhea. Although there are a lot of research at the molecular and cellular level to study the Semen Cuscutae on the treatment of Kidney yang deficiency syndrome, but there's no comprehensive research complete with metabolomics method from plasma, feces and urine metabolites aspects. The purpose of this study is to find the potential differential biomarkers of the Kidney yang deficiency model and blank group rats in plasma, urine and feces, and to investigate the mechanism of Semen Cuscutae in the treatment of Kidney yang deficiency syndrome. In this study, ultra high-performance liquid chromatography-quadrupole time-of-flight Mass Spectrometry (UPLC-QTOF/MS) was used to identify potential biomarkers. Through the analysis of metabolic profiles of plasma, urine, and feces, as well as multivariate statistical analysis and pathway analysis, the therapeutic mechanism of Semen Cuscutae for Kidney yang deficiency syndrome was described. The results showed that there were 69 differential metabolites in plasma, 93 differential metabolites in feces and 62 differential metabolites in urine, and the changes of the levels of these biomarkers showed that Semen Cuscutae had a good therapeutic effect on Kidney yang deficiency syndrome. Through the analysis of the channel, the metabolite changes mainly affected the steroid hormone biosynthesis, arachidonic acid metabolism, primary bile acid biosynthesis, sheath lipid metabolism and biosynthesis of tyrosine, phenylalanine metabolism, retinol metabolism,taurine and hypotaurine metabolism, lysine degradation and vitamin B6 metabolism, tryptophan metabolism, terpenoid backbone biosynthesis and starch and sucrose metabolism. Therefore, the results suggested that Semen Cuscutae could exert a good therapeutic effect by reversing the levels of some biomarkers.

Simultaneous determination of ten flavonoids from Viscum coloratum grown on different host species and different sources by LC-MS.

A high-performance liquid chromatographic-mass spectrometric method was developed for the simultaneous determination of 10 flavonoids in Viscum coloratum obtained from different host species and different sources. Viscum coloratum was extracted with 50% methanol. The extracts were separated on a C(18) column with a gradient of 0.1% (v/v) formic acid and methanol. The flavonoids in the extracts were detected by negative electrospray ionization mass spectrometry in selective ion monitoring mode. The calibration curves showed good linearity (r>0.998) within the test ranges (homoeriodictyol: 0.149-8.940 µg/ml, homoeriodictyol-7-O-ß-D-glycoside: 0.230-13.80 µg/ml, homoeriodictyol-7-O-ß-D-apiose (1→2)-ß-D-glycoside: 5.000-300.0 µg/ml, homoeriodictyol-7-O-ß-D-apiose (1→5)-ß-D-apiose (1→2)-ß-D-glycoside: 0.835-125.3 µg/ml, rhamnazin-3-O-ß-D-glucoside: 0.064-3.840 µg/ml, rhamnazin-3-O-ß-D-(6″-ß-hydroxy-ß-methyglutaryl)-glucoside: 1.435-86.10 µg/ml, isorhamnetin-3-O-ß-D-glucoside: 0.930-55.80 µg/ml, 5-hydroxy-3,7,3'-trimethoxyflavone-4'-O-ß-D-glucoside: 0.067-4.020 µg/ml, 5,7,4'-trihydroxy-3,3'-dimethoxyflavone: 0.270-16.20 µg/ml, pachypodol: 0.110-6.600 µg/ml). The limits of quantification were between 0.006-0.720 µg/ml. The assay was reproducible and the overall intra- and inter-day variations were less than 4.6%. The recoveries varied from 93.4 to 103.9% at three different concentration levels. The validation method was used to determine the contents of 10 flavonoids in Viscum coloratum. A one-way analysis of variance was applied to evaluate Viscum coloratum-host-source interactions. Compared with the host species, the sample source had a significant impact on the sample content.

A highly sensitive competitive immunosensor based on branched polyethyleneimine functionalized reduced graphene oxide and gold nanoparticles modified electrode for detection of melamine.

Branched polyethyleneimine functionalized reduced graphene oxide (BPEIGn) was prepared by a one-step reaction, catalyzed by NaOH, using branched polyethyleneimine (BPEI) and graphene oxide (GO) without reductant hydrazine hydrate or sodium borohydride. The branched polyethylenimine acted as both a grafting agent and a reducing agent of GO. An competitive electrochemical immunosensor based on the Au/sodium mercaptopropanesulfonate/BPEIGn/gold nanoparticles/melamine (Au/MPS/BPEIGn/AuNPs/Mel) modified electrode was constructed for the determination of melamine. The double amplification of BPEIGn and AuNPs increased the sensitivity of the sensor. The melamine was detected by differential pulse voltammetry (DPV) in buffer solution (pH 7.4) containing K3(Fe(CN)6]/K4[Fe(CN)6]. Under optimized conditions, the proposed melamine immunosensor showed a linear relationship in the concentration range of 1 × 10-6 to 1 µM, with a detection limit of 2.66 × 10-7 µM.

High resolution UPLC-MS/MS method for simultaneous separation and determination of six flavonoids from semen cuscutae extract in rat plasma: application to comparative pharmacokinetic studies in normal and kidney-deficient rats.

Semen Cuscutae, which mainly consisted of flavonoids, is a traditional Chinese herbal medicine and used for nourishing the liver and kidneys. The aim of this study was to develop a sensitive and selective UPLC-MS/MS method for simultaneous separation and determination of six main active renoprotective components of Hyperoside, Astragalin, Isoquercitrin, Quercitrin, Quercetin, and Kaempferol from Semen Cuscutae in rat plasma, and to reveal the pharmacokinetic differences between normal and kidney deficient rats. The validated method has been successfully applied to comparing pharmacokinetic profiles of the six analytes in rat plasma. The results indicated that there was significant difference in pharmacokinetic parameters of the six analytes between two groups, while absorptions in kidney deficient group were significantly lower than those in normal group. This study would be helpful for evaluating the Semen Cuscutae as renoprotective drug candidates for pre-clinical and clinical research.

Determination of endogenous substance change in PM2.5-induced rat plasma and lung samples by UPLC-MS/MS method to identify potential markers for lung impairment.

Exposure to fine particulate matter (PM2.5) could induce lung impairment aggravation. Moreover, endogenous substances are known to play a significant role in lung impairment. Therefore, the research objectives was to investigate the influence of PM2.5-induced lung impairment on the levels of the eight endogenous substances, γ-aminobutyric acid (GABA), acetylcholine (ACh), glutamate (Glu), serotonin (5-HT), 5-hydroxyindole-3-acetic acid (5-HIAA), noradrenaline (NE), dopamine (DA), and 3, 4-dihydroxyphenylacetic acid (DOPAC). A sensitive UPLC-MS/MS method for the simultaneous determination of these endogenous substances in rat plasma and lung tissues was developed. The validated method was successfully applied for comparing profiles of analytes in rat plasma and lung tissues. The results indicated that five endogenous substances, namely, GABA, Ach, Glu, DA, and DOPAC, had a significant change in the rats with PM2.5-induced lung impairment.

Simultaneous identification and quantification of the common compounds of Viscum coloratum and its corresponding host plants by ultra-high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry and triple quadrupole mass spectrometry.

Viscum coloratum is a perennial evergreen, semi-parasitic plant. It is generally used for treating cardiovascular diseases, cancer, hepatitis and hemorrhage. In this study, reliable methods were developed for the qualitative and quantitative analysis of the common constituents in Viscum coloratum and its corresponding host. In the rapid qualitative analysis, a method of ultra-high performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry was established for identification of the same compounds. Based on the retention times, accurate mass measurement and previous literatures, 23 components were clearly identified by comparison with reference substances. In the quantitative analysis, a method for Viscum coloratum and its corresponding host was developed by ultra-high performance liquid chromatography with triple quadrupole mass spectrometry. 13 common compounds of viscum coloratum and host plants from 19 batches were analyzed with a good linearity (r2≥0.9991), intra-day precision (RSD≤3.24%), inter-day precision (RSD≤3.31%), repeatability (RSD≤2.43%), stability (RSD≤2.63%), and recovery (98.2-102.4%). The overall limits of quantification were less than 5.0ng/mL. The results indicated that these effective and comprehensive methods can be applicable to simultaneous qualitative and quantitative analysis of these common compounds presented in Viscum coloratum and corresponding host plants.

Water-dispersible triethylenetetramine-functionalized graphene: Preparation, characterization and application as an amperometric glucose sensor.

The triethylenetetramine-functionalized graphene (TFGn) was prepared using graphene oxide (GO) and triethylenetetramine as raw materials through a one-step reaction under alkaline condition. The triethylenetetramine not only acted as cross-linker to combine GO, but also as reductant of GO. The TFGn was characterized by its ultraviolet spectrum (UV), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy and Scanning electron microscopy (SEM). The results showed that triethylenetetramine was successfully grafted onto the surface of the GO through covalent bonding between amine and epoxy groups. The resultant TFGn was uniformly dispersed in water over several weeks, suggesting that the introduction of amino groups greatly increased the hydrophilicity of TFGn. The triethylenetetramine-functionalized graphene was then applied to fabricate glucose biosensors with IO4(-) oxidized glucose oxidase (GOx) through layer-by-layer (LBL) self-assembly by the covalent bonding between the aldehyde groups of GOx and amino groups of TFGn. The gold electrodes modified with the (GOx/TFGn)n multilayer films were studied by cyclic voltammetry (CV) and showed outstanding electrocatalytical response to the oxidation of glucose when ferrocenemethanol was used as an artificial redox mediator. The response increased with an increasing number of GOx/TFGn bilayers, indicating that the analytical performance, such as the sensitivity of the glucose biosensor, could be adjusted by tuning the number of deposited GOx/TFGn bilayers. The linear response range of the biosensor constructed with six bilayers of GOx/TFGn to the concentration of glucose can extend to at least 8mM with a sensitivity of 19.9µAmM(-1)cm(-2). In addition, the sensor exhibited good stability due to the covalent interactions between the GOx and TFGn.

A study of pharmacokinetic interactions among co-existing ingredients in Viscum coloratum after intravenous administration of three different preparations to rats.

BACKGROUND: Viscum coloratum (Komar) Nakai, known as Hujisheng in china, has been widely used as a herb medicine to treat a variety of diseases, including cardiovascular diseases, cancer, hypertension, hepatitis and hemorrhage. OBJECTIVE: The aim was to investigate pharmacokinetic interactions among co-existing ingredients in V. coloratum after intravenous administration of three different preparations (four monomer solutions, the mixture of them and Viscum coloratum extracts) to rats. MATERIALS AND METHODS: After protein precipitation pretreatment with plasma samples, high performance liquid chromatographic methods were developed and applied to quantitatively determinate the four components [syringin (Syri), homoeriodictyol-7-O-ß-D-glycoside (Hedt-III), homoeriodictyol-7-O-ß-D-apiose (1 → 2)-ß-D-glycoside (Hedt-II) and homoeriodictyol-7-O-ß-D-apiosiyl-(1 → 5)-ß-D-apiosyl-(1 → 2)-ß-D-glycoside (Hedt-I)]. The pharmacokinetic parameters (Area under the curve [AUC(0-t)], AUC(0-∞), t 1/2) were calculated using DAS 2.1 software (Chinese Pharmacological Society, Shanghai, China) and compared statistically by One-way analysis of variance using SPSS software (18.0, Chicago, IL, USA) with P < 0.05 considered statistically significant. RESULTS: Good linearities were achieved in the measured concentration range with R (2) it0.9920. Precision, accuracy and extraction recovery were all within the acceptable range. For Syri, there was a significant difference only on t 1/2 among three treatment groups. For Hedt-I, Hedt II and Hedt-III, three flavonoid glycosides, the change of AUC(0-t), AUC(0-∞) and t 1/2 were markedly distinctive and even converse. CONCLUSION: Complex, extensive pharmacokinetic interactions were observed among these components in V. coloratum. They were mutually influenced by the in vivo absorption, distribution, metabolism and elimination. The result suggested traditional Chinese medicine was a complicated system, and we should take a scientific and dialectic view in the research and development processes.

Application of an LC-MS/MS method to the pharmacokinetics of TM-2, a potential antitumour agent, in rats.

TM-2 is a novel semi-synthetic taxane derivative, selected for preclinical development based on its greater anticancer activity and lower toxicity compared with docetaxel. In this study, a rapid and sensitive analytical method based on ultra performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of TM-2 in rat plasma. The biological samples were extracted with methyl tert-butyl ether and separated on a C18 column (50 mm × 2.1 mm, 1.7 µm) using a mobile phase consisting of acetonitrile and 2 mM ammonium acetate. The standard curves were linear over the range 5-1000 ng/mL in rat plasma. The precision (relative standard deviation, RSD, %) were within 14.5%, and the accuracy (relative error, RE, %) ranged from -1.56 to 2.36%. Recovery and matrix effect were satisfactory in rat plasma. The validated method was successfully applied to pharmacokinetic studies after intravenous administration of TM-2 to rats. The pharmacokinetics of TM-2 in rats were characterized by a large volume of distribution and a long half-life of elimination after single dose (4, 8, and 16 mg/kg), and a good correlation was observed between AUC and dose. The preclinical data will be useful for the design of subsequent trials of TM-2.