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1.
Comparative pharmacokinetic study on three formulations of Astragali Radix by an LC-MS/MS method for determination of formononetin in human plasma.
Rao, T, Gong, YF, Peng, JB, Wang, YC, He, K, Zhou, HH, Tan, ZR, Lv, LZ
Biomedical chromatography : BMC. 2019;(9):e4563
Abstract
Astragali Radix (AR) is a widely used traditional Chinese medicine for healing the cardiovascular, liver and immune systems. Recently, superfine pulverizing technology has been applied to developing novel formulations to improve bioavailability of the active constituents in herbs, such as ultrafine granular powder of AR. In this study, a universal and sensitive quantitative method based on LC-MS/MS was employed for determining formononetin, the main flavonoid in AR, in human plasma for comparative pharmacokinetics of three oral formulations of AR. Formononetin and IS (quercetin) were extracted by ethyl acetate from human plasma and were separated on a C18 column with a mobile phase consisting of acetonitrile and 0.1% formic acid. Positive-ion electrospray-ionization mode was applied in mass spectrometric detection. The quantitative method was validated with regards to selectivity, linearity, accuracy and precision, matrix effect, extraction recovery and stability, and was applied to comparing the pharmacokinetics of ultrafine granular powder (UGP), ultrafine powder (UP) and traditional decoction pieces (TDP) of AR after oral administration. The peak concentration and areas under the concentration-time curve of formononetin in UGP and UP were significantly higher than those of TDP. UGP and UP could significantly improve the bioavailability of AR in human compared with TDP after oral administration.
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2.
Development of a simple HPLC-MS/MS method to simultaneously determine teriflunomide and its metabolite in human plasma and urine: Application to clinical pharmacokinetic study of teriflunomide sodium and leflunomide.
Yao, X, Liu, Y, Song, L, Jiang, J, Xiao, F, Liu, D, Hu, P
Biomedical chromatography : BMC. 2019;(3):e4420
Abstract
A simple high-performance liquid chromatography coupled with tandem mass spectrometry method was developed and fully validated to simultaneously determine teriflunomide (TER) and its metabolite 4-trifluoro-methylaniline oxanilic acid (4-TMOA) in human plasma and urine. Merely 50 μL plasma and 20 μL urine were employed in sample preparation using protein precipitation and direct dilution method, respectively. An Agilent Zorbax eclipse plus C18 column was selected to achieve rapid separation for TER and 4-TMOA within 3 min. Electrospray ionization under multiple reaction monitoring was used to monitor the ion transitions for TER (m/z 269.0 → 159.9), 4-TMOA (m/z 231.9 → 160.0), internal standard teriflunomide-d4 (m/z 273.0 → 164.0) and 2-amino-4-trifluoromethyl benzoic acid (m/z 203.8 → 120.1), operating in the negative ion mode. This method proved to have better accuracy and precision over concentration range of 10-5000 ng/mL in plasma as well as 10-10,000 ng/mL in urine. After a full validation, this method was successfully applied in a pharmacokinetic study of teriflunomide sodium and leflunomide in Chinese healthy volunteers.
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3.
Miniaturized shake-flask HPLC method for determination of distribution coefficient of drugs used in inflammatory bowel diseases.
Brusač, E, Jeličić, ML, Klarić, DA, Mornar, A
Acta pharmaceutica (Zagreb, Croatia). 2019;(4):649-660
Abstract
A new method for determination of distribution coefficient of drugs azathioprine, 6-mercaptopurine and 6-thioguanine and nutrient folic acid used in the treatment of inflammatory bowel disease based on a miniaturized shake-flask and HPLC/DAD was developed. Special attention was made to the most commonly reported problems in the measurement of distribution coefficients using a shake-flask method such as mixing technique, speed and time, the temperature of experiment, type of buffer and its pH as well as n-octanol/buffer phase ratio. The concentration of compounds in the buffer is determined by HPLC directly from shake flasks or conventional 2-mL vials. The developed method was fully validated according to ICH guidelines. Furthermore, experimental data were successfully compared with lipophilicity and human intestinal absorption calculated by the use of four different theoretical approaches. The method shows potential for high-throughput measurements of a large number of compounds.
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4.
Simultaneous determination of saflufenacil and three metabolites in five agriculture products using liquid chromatography-Tandem mass spectrometry.
Wu, C, Liu, X, Wu, X, Dong, F, Xu, J, Zheng, Y, Zheng, Y
Journal of food biochemistry. 2019;(4):e12778
Abstract
A reliable and efficient method was firstly established for the simultaneous determination of saflufenacil and its metabolites (M800H02, M800H11 and M800H35) in cereals (soybean and corn) and fruits (apple, grape and orange), based on a triple quadrupole liquid chromatography mass spectrometer. The four target compounds were extracted with acetonitrile and purified by Florisil or Florisil with octadecylsilane from the cereals and fruits. Determination of the targets was achieved within 3.5 min by using Shim-pack GIST C18 column connected to an electrospray ionization source (ESI- mode). The method showed excellent linearity (R2 > 0.9984), and the limits of quantitation were 1 µg/kg for all compounds. Average recoveries were in the range of 74.6%-108.1%, with an intra-day relative standard deviation between 0.9% and 18.3%. The inter-day relative standard deviation was less than 13.8%. The results demonstrate that this method is convenient for monitoring the residues of saflufenacil and its metabolites in food matrices. PRACTICAL APPLICATIONS Saflufenacil controls many common annual broadleaf weed efficiently, it has been developed and launched into the market by domestic enterprises. Consequently, an analysis method for monitoring saflufenacil in food sample will be urgently needed in China over the next few years. This method provides separation with good specificity within 3.5 min, which is less than previous studies. For the five matrixes, the method presented satisfactory validation parameters in terms of good linearity, low limit of quantitations, and satisfactory accuracy and precision. Therefore, the method established in this study is a valuable tool to overcome gaps in determining saflufenacil and its metabolites in cereals and fruits, in order to accurate evaluation of risk and ensure food safety.
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5.
Simultaneous qualitative and quantitative evaluation of Toddalia asiatica root by using HPLC-DAD and UPLC-QTOF-MS/MS.
Zhu, M, Wei, P, Peng, Q, Qin, S, Zhou, Y, Zhang, R, Zhu, C, Zhang, L
Phytochemical analysis : PCA. 2019;(2):164-181
Abstract
INTRODUCTION Coumarin and alkaloids are the major bioactive constituents of Toddalia asiatica, playing an important role in various biological activities such as anti-inflammatory, analgesic, anti-bacterial and anti-tumour. OBJECTIVE To establish a method that will simultaneously determine the coumarins and alkaloids compounds in T. asiatica and identify their characteristic fragmentation patterns, while combining fingerprints and chemical identification with chemometrics for discrimination and quality assessment of T. asiatica samples. METHODOLOGY Qualitative characterisation of coumarins and alkaloids compounds in the methanol extracts of T. asiatica was determined by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS). Quantitative analysis relies on high-performance liquid chromatography with a diode array detector (HPLC-DAD). RESULTS A total of 59 components were characterised by UPLC-QTOF-MS/MS, including 29 coumarin, 25 alkaloids, one phenolic acid and four flavonoids. While the 19 characteristic components out of 23 common peaks in the chromatographic fingerprints of T. asiatica were confirmed. Quantitative analysis of seven major compounds from 18 samples were simultaneously detected by HPLC-DAD at wavelengths of 280 nm. The samples were classified into three groups by hierarchical clustering analysis (HCA) combined with principal component analysis (PCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) which screened out the main chemical markers responsible for the samples differences. CONCLUSION Fingerprints combined with chemometrics and chemical identification are a simple, rapid and effective method for the quality control of T. asiatica.
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6.
Lipophilicity and bio-mimetic properties determination of phytoestrogens using ultra-high-performance liquid chromatography.
Lasić, K, Bokulić, A, Milić, A, Nigović, B, Mornar, A
Biomedical chromatography : BMC. 2019;(8):e4551
Abstract
This paper presents lipophilicity and bio-mimetic property determination of 15 phytoestrogens, namely biochanin A, daidzein, formononetin, genistein, genistein-4,7-dimethylether, prunetin, 3,4,7-trihydroxyisoflavon, 4,6,7-trihydroxyisoflavon, 4,6,7-trimethoxyisoflavon, daidzin, genistin, ononin, sissotrin, coumestrol and coumestrol dimethylether. High-performance liquid chromatography with fast gradient elution and Caco-2 cell line were used to determine the physicochemical properties of selected phytoestrogens. Lipophilicity was determined on octadecyl-sylane stationary phase using pH 2.0 and pH 7.4 buffers. Immobilized artificial membrane chromatography was used for prediction of interaction with biological membranes. Protein binding was measured on human serum albumin and α-1-acid-glycoprotein (AGP) stationary phases. Caco-2 assay was used as a gold standard for assessing in vitro permeability. The obtained results differentiate phytoestrogens according to their structure where aglycones show significantly higher lipophilicity, immobilized artificial membrane partitioning, AGP binding and Caco-2 permeability compared with glucosides. However, human serum albumin binding was very high for all investigated compounds. Furthermore, a good correlation between experimentally obtained chromatographic parameters and in silico prediction was obtained for lipophilicity and human serum albumin binding, while the somewhat greater difference was obtained for AGP binding and Caco-2 permeability.
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7.
HPLC Enantioseparations with Polysaccharide-Based Chiral Stationary Phases in HILIC Conditions.
Cirilli, R
Methods in molecular biology (Clifton, N.J.). 2019;:127-146
Abstract
In contrast to achiral hydrophilic interaction liquid chromatography (HILIC), which is a popular and largely applied technique to analyze polar compounds such as pharmaceuticals, metabolites, proteins, peptides, amino acids, oligonucleotides, and carbohydrates, the introduction of the HILIC concept in enantioselective chromatography has been relatively recent and scarcely debated. In this chapter, the HILIC enantioseparations carried out on polysaccharide-based chiral stationary phases are grouped and discussed. Another objective of this chapter is to provide a comprehensive overview and insight into the experimental conditions needed to operate under HILIC mode. Finally, to stimulate and facilitate the application of this chromatographic technique, a detailed experimental protocol of a chiral resolution on a chlorinated cellulose-based chiral stationary phase under HILIC conditions is described.
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8.
Method development for simultaneous determination of polar and nonpolar pesticides in surface water by low-temperature partitioning extraction (LTPE) followed by HPLC-ESI-MS/MS.
de Barros, ALC, de Abreu, CG, da Cunha, CCRF, da Silva Rodrigues, DA, Afonso, RJCF, da Silva, GA
Environmental science and pollution research international. 2019;(31):31609-31622
Abstract
During this research, chemometric approaches were applied for optimization of the low-temperature partitioning extraction (LTPE) for the simultaneous analysis of the pesticides: acephate, difenoconazole, fenamidone, fluazifop, fluazinam, methamidophos, and thiamethoxam from surface water samples and determination by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. It was used the 23 full factorial and the Doehlert experimental designs. The extraction technique was optimized by evaluating the effects of the three variables: sample pH, ionic strength (addition of Na2HPO4), and organic solvent volume. Considering the interest to find an optimal condition for all analytes simultaneously, the best extraction parameters found were as follows: pH = 5.33, concentration of Na2HPO4 = 0.0088 mol L-1 and organic phase volume = 4.5 mL. The optimized methodology showed LOD and LOQ levels from 0.33 to 8.13 ng L-1 and from 1.09 to 26.84 ng L-1, respectively. The recovery values ranged from 38.37 and 99.83% and the RSD values varied from 2.33 to 18.92%. The method was applied to surface water analysis sampled in areas with intensive agricultural practices in Ouro Branco City, Minas Gerais, Brazil. The difenoconazole was detected in concentrations between 12.53 and 94.76 ng L-1.
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9.
Determination of Selected Pyrrolizidine Alkaloids in Honey by Dispersive Liquid-Liquid Microextraction and Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.
Celano, R, Piccinelli, AL, Campone, L, Russo, M, Rastrelli, L
Journal of agricultural and food chemistry. 2019;(31):8689-8699
Abstract
The contamination of honey with hepatotoxic pyrrolizidine alkaloids (PAs) is an actual concern for food safety. This study reports the first application of dispersive liquid-liquid microextraction (DLLME) in the determination of five relevant PAs, and the relative N-oxide derivatives (PANOs), in honey. The effects of different experimental parameters (pH, ionic strength, type and volume of DLLME solvents) affecting the extraction efficiency were carefully investigated and optimized. PAs were extracted from honey (diluted solution 10% w/v at pH 9.5) by injecting a mixture of chloroform and isopropyl alcohol. A reduction step (zinc powder in acidic aqueous solution) before DLLME was performed to convert PANOs in PAs and to obtain the total PA levels. Both sample preparation protocols (DLLME and Zn-DLLME) showed negligible matrix effects on PA signal intensity in honeys of different botanical origins. The overall recoveries of DLLME and Zn-DLLME ranged from 71 to 102% and from 63 to 103%, respectively, with a good precision (standard deviations in the range from 1 to 12%). The attained method quantification limits stayed between 0.03 and 0.06 μg kg-1, and the linear response range extended to 25 μg kg-1. Additionally, the proposed method provides results comparable to those of the SPE protocol in the analysis of real samples. An analysis of retail honeys revealed PA residues in all analyzed samples, with a maximum level of 17.5 μg kg-1 (total PAs). Globally, the proposed method provides a sensitive and accurate determination of analytes and offers numerous advantages, such as simplicity, low cost, and a high sample throughput, which make it suitable for screening and quality control programs in food chain and occurrence studies.
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10.
An UHPLC-MS/MS Method for Target Profiling of Stress-Related Phytohormones.
Novák, O, Floková, K
Methods in molecular biology (Clifton, N.J.). 2018;:183-192
Abstract
The methodology described here represents an improved strategy for analysis of a broad range of stress-related plant hormones including jasmonates, salicylic acid, abscisic acid, and auxin metabolites. The method conditions are optimized in order to reduce the background effect of complicated plant matrix, allow effective preconcentration and thus perform highly sensitive profiling of multiple plant hormones by ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).