Simultaneous Determination of Isopyrazam and Azoxystrobin in Cucumbers by Liquid Chromatography-Tandem Mass Spectrometry.

A rapid and sensitive analytical method based on high-performance liquid chromatography-tandem mass spectrometry was developed and validated for the determination of isopyrazam (IZM) and azoxystrobin (AZT) in cucumbers. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used as the pretreatment procedure. The samples were extracted with acetonitrile and cleaned up with octadecylsilyl silica (C18) and graphite carbon black.

Unexpected hydrated ions in the detection of sodium adduct coumarins using electrospray tandem mass spectrometry.

A series of coumarins were analyzed using electrospray ionization quadrupole time-of-flight tandem mass spectrometry in the positive-ion mode. Unexpected hydrated ions ([M + HO + Na]) was observed upon collision-induced dissociation of the sodiated ions ([M + Na]) of eight coumarins. Several factors which affected relative abundance of [M + HO + Na] ions such as collision energy, concentration and solvent were investigated.

[The Study of Methodology Validation in Multicomponent Quantitative Analysis of Raman Spectroscopy].

Raman spectroscopy with the help of sophisticated data analysis techniques based on multivariate analysis have made it possible to study the full information of Raman spectra and to draw conclusions about the chemical structure and composition of very complex systems. As Raman spectroscopy has the advantage to provide rich information of the sample, so it was first included in Chinese Pharmacopoeia (2010) as “Annex XIX L Guidelines of Raman spectroscopy”. However the validation method for multicomponent quantitative analysis of Raman spectroscopy was not discussed in this pharmacopoeia.

UDP-glucosyltransferase71c5, a major glucosyltransferase, mediates abscisic acid homeostasis in Arabidopsis.

Abscisic acid (ABA) plays a key role in plant growth and development. The effect of ABA in plants mainly depends on its concentration, which is determined by a balance between biosynthesis and catabolism of ABA. In this study, we characterize a unique UDP-glucosyltransferase (UGT), UGT71C5, which plays an important role in ABA homeostasis by glucosylating ABA to abscisic acid -: glucose ester (GE) in Arabidopsis (Arabidopsis thaliana).

Simultaneous determination of thirteen aminoalcohol-diterpenoid alkaloids in the lateral roots of Aconitum carmichaeli by solid-phase extraction-liquid chromatography-tandem mass spectrometry.

Aminoalcohol-diterpenoid alkaloids have been reported as the cardioactive components in the lateral roots of Aconitum carmichaeli (Fuzi) according to recent studies. Determination of these effective components is of great significance for quality control purposes for Fuzi. Here we report, for the first, the development and validation of a new method to determine the 13 aminoalcohol-diterpenoid alkaloids in Fuzi by using a simple and accurate solid-phase extraction-liquid chromatography-tandem mass spectrometry.

Profiling the dynamics of abscisic acid and ABA-glucose ester after using the glucosyltransferase to mediate abscisic acid homeostasis in by HPLC-ESI-MS/MS.

The HPLC-MS/MS method was developed to profile the dynamics of abscisic acid (ABA) and ABA-glucose ester (ABA-GE) after cloning glycosyltransferase enzyme family gene into . By constructing over-expression lines (OE) and down-expression lines (DN), we acquired mutant strains to analyze the function of . The multiple-reaction monitoring (MRM) was used for quantitative determination in negative mode.

Release test of alliin/alliinase double-layer tablet by HPLC-Allicin determination.

A simple, precise and accurate method was developed and validated for the determination of allicin release from alliin/alliinase double-layer tablets. According to Appendix XC II of Chinese Pharmacopoeia 2010 edition Volume II, a small glass-method was adopted at the rotational speed of 100 r/min using 100 mL phosphate buffer (pH 6.8) as release medium.

[Monitoring urine metabolic profiles of rat inflammation model with capillary electrophoresis].

Objective: To determine the comprehensive metabolic profiling of inflammation with capillary zone electrophoresis (CZE) in rat urine.

Methods: CZE-based metabolomics method was used to acquire urine metabolom data, with Computer Aided Similarity Evaluation System aligning peaks and analyzing urine profiling. Principle component analysis (PCA) was performed to compare and classify the phenotypes of the urine CZE spectra.

Effect of acupuncture on rats with acute gouty arthritis inflammation: a metabonomic method for profiling of both urine and plasma metabolic perturbation.

Acute gouty arthritis is a common inflammation model with multiple pathogenic mechanisms seen in clinical practice, for which acupuncture may potentially be an alternative therapy. To investigate the effect of acupuncture on acute gouty arthritis and search for its mechanism, a metabonomic method was developed in this investigation. Acute gouty arthritis model rats were induced by monosodium urate (MSU) crystals.

[Metabonomic study of the urine of rat acute gouty arthritis model].

Unlabelled: [

Objective: To analysis the metabonome characteristics of the urine of MSU crystal-induced acute gouty arthritis rats by the method of metabolomics.

Methods: Based on the method of metabolomics, which applies LC/MS as data acquisition platform, incorporating with the means of stoechiometry such as principal component analysis, we analyzed the metabonome difference between the urine of acute gouty arthritis rats and that of normal rats.

Results: Compare with control group, the metabolism status of acute gouty arthritis model group deviated.

Quantitative retention-activity relationship models of angiotensin converting enzyme inhibitors using biopartitioning micellar chromatography.

Biopartitioning micellar chromatography (BMC) is a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 under adequate experimental conditions and can simulate biopartioning process of many kinds of drugs and describe their biological behavior. The capability of BMC to describe and estimate pharmacokinetic and pharmacodynamic parameters of angiotensin-converting enzyme inhibitors (ACEIs) had been studied in this paper. The correlation between retention factors of ACEIs obtained using BMC and bioactivity parameters (half-life, volume of distribution, clearance, and IC(50)) was investigated utilizing a second-order polynomial model.

[Determination of sinigrin in semen Thlaspi from Sichuan and Tibet using near infrared diffuse reflectance spectroscopy].

The objective of the present study was to develop a method for the determination of sinigrin in semen Thlaspi from Sichuan using near infrared diffuse reflectance spectroscopy. Near infrared spectra (NIR) in the region of 7,502.1-5,446.

Development of predictive quantitative retention-activity relationship models of alkaloids by mixed micellar liquid chromatography.

The mixed micellar liquid chromatography is a mode that uses mixed micellar system of Brij35/SDS (85 : 15) as a mobile phase under adequate experimental conditions, can simulate the resting membrane potential and the conformation of the long hydrophilic polyoxyethylene chains remains unchanged. In this article, the applications of biopartitioning micellar chromatography, using mixed micellar system to describe and estimate bioactivities of alkaloids, has been focused. The BMC(Brij35/SDS)-QRAR models of half-life time, volume of distribution, plasma clearance and area under concentration-time curve were obtained using Brij35-SDS retention data.

Intra-herb pharmacokinetics interaction between quercetin and isorhamentin.

Aim: Quercetin and isorhamnetin are common constituents of some herb extracts, such as extracts of gingko leaves and total flavones of Hippophae rhamnoides L. The intra-herb pharmacokinetics interactions between isorhamnetin and quercetin were investigated in the present study.

Methods: Human MDR1 cDNA transfected MDCKII cells were used to validate whether isorhamnein interacted with P-gp.

Mixed micellar liquid chromatography methods: modelling quantitative retention-activity relationships of angiotensin converting enzyme inhibitors.

The capability of biopartitioning micellar chromatography (BMC), using pure Brij35 solution and mixed micellar system of Brij35-SDS (85:15) as mobile phase, to describe and estimate bioactivities of angiotensin converting enzyme inhibitors at different pH has been studied. Quantitative retention-activity relationships (QRAR) in BMC were investigated for these compounds. The obtained BMC(Brij35-SDS)-QRAR models were compared with the traditional BMC(Brij35)-QRAR, and better statistically models were obtained using Brij35-SDS retention data.

[Determination of isorhamnetin in Hippophae rhamnoides Linn from West Sichuan plateau using near infrared diffuse reflectance spectroscopy].

The objective of this study was to develop a method for the determination of isorhamnetin in Hippophae rhamnoides Linn from West Sichuan plateau using near infrared diffuse reflectance spectroscopy. Applying the method of mixing with SiO2, the near infrared spectra (NIS) with the range of 12 000-4 000 cm(-1) were recorded for the Hippophae rhamnoides Linn containing isorhamnetin with the content of 0.1%-0.

Biopartitioning micellar chromatography separation methods: modelling quantitative retention-activity relationships of cephalosporins.

In this article, recent applications of chromatographic systems, particularly biopartitioning micellar chromatography (BMC) systems based on amphiphilic structures, have been reported. The aim is to take a look at the capability of quantitative retention-activity relationship (QRAR) models with BMC to describe and/or estimate the bioactivity of cephalosporins. Better qualification of BMC systems was obtained according to the octanol-water partition coefficient (log P); the bioactivity parameters (Lag-T, T(1/2beta), F%, T(1/a), P%, AUC and C(max)) were correlated with the retention factors of cephalosporins processed by Alltech-chromstation software, and the classical data were compared with the predictive values based on QRAR models.

Development of predictive quantitative retention-activity relationship models of HMG-CoA reductase inhibitors by biopartitioning micellar chromatography.

Biological fluid cell membranes are barriers for the uptake of many kinds of drugs and their metabolites, along with passive transport across membranes and bioaccumulation. Biopartitioning micellar chromatography (BMC) is a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 under adequate experimental conditions and can be useful to simulate the drug's passive absorption and the transport in biological systems. The use of micellar aqueous solutions of Brij35 as mobile phases in reversed-phase liquid chromatography has proven to be valid to predict the biological activities of barbiturates, benzodiazepines, catecholamines, local anesthetics, non-steriodal anti-inflammatory drugs and tricyclic antidepressants.

Quantitative retention-activity relationship models for quinolones using biopartitioning micellar chromatography.

A simple and reproducible quantitative retention-activity relationship (QRAR) model utilizing biopartitioning micellar chromatography was developed for the biological parameter estimation of drugs. The correlation between retention factors of quinolones obtained in physiological conditions (pH, ionic strength) and biological activities was investigated using different second-order polynomial models. The predictive and interpretative ability of the chromatographic models was evaluated in terms of cross-validated data (RMSEC, RMSECV and RMSECVi).

[Study on quality evaluation methods of pretreatment for polystyrene-type macroporous absorbing resins].

Objective: To establish a GC method using wide bore open tubular columns f or controlling pretreatment for polystyrene-type macroporous absorbing resins and its eligible standard.

Method: A model macroporous absorbing resins made in our lab was eluted by anhydrous alcohol. The residual solvents in elution (xylene, styrene, diethylbenzene, divinybenzene, decane) were assayed by GC.