- 18F-labeled ethisterone derivative for progesterone receptor targeted PET imaging of breast cancer. [Journal Article]
- NMNucl Med Biol 2019 Jul 12; 72-73:62-69
- CONCLUSIONS: A novel [18F]FPTT probe based on ethisterone modification could be a potential diagnostic agent for PR-positive breast cancer.
- VMAT2 imaging agent, D6-[18F]FP-(+)-DTBZ: Improved radiosynthesis, purification by solid-phase extraction and characterization. [Journal Article]
- NMNucl Med Biol 2019 Jul 11; 72-73:26-35
- CONCLUSIONS: A VMAT2 targeting imaging agent, D6-[18F]FP-(+)-DTBZ, [18F]9, was prepared by optimized labeling conditions and an easy SPE purification. This method offers a short preparation time and operational simplicity. In conjunction with PET imaging, this new VMAT2 agent might be a useful clinical tool for diagnosing PD.
- Microwave assisted high performance liquid chromatography for the separation of triacylglycerols in vegetable oils using an evaporative light scattering detector. [Journal Article]
- FCFood Chem 2019 Jul 17; 300:125203
- Microwave (MW) radiation was applied to perform the separation of triacylglycerols (TGs) in oil samples. The novelty of the work lies in the application of MW radiation to assist the separation of se…
Microwave (MW) radiation was applied to perform the separation of triacylglycerols (TGs) in oil samples. The novelty of the work lies in the application of MW radiation to assist the separation of several non-polar compounds employing a totally organic mobile phase. Once the influence of the evaporative light scattering detector (ELSD) variables on the sensitivity was optimized, the TGs separation was compared conditioning the column with either a conventional HPLC or a MW oven. Contrary to previous applications in which the mobile phase contained water, the improvement in sensitivity using MW was not as significant in comparison with conventional heating but it allowed a shortening in the retention times of several TGs in about 50% respect elution at room temperature. The method was finally applied for the quantification of most common TGs in almond, tiger nut, and argan oil.
- Temperature alters susceptibility of Picea abies seedlings to airborne pollutants: The case of CdO nanoparticles. [Journal Article]
- EPEnviron Pollut 2019 Jul 13; 253:646-654
- Although plants are often exposed to atmospheric nanoparticles (NPs), the mechanism of NP deposition and their effects on physiology and metabolism, and particularly in combination with other stresso…
Although plants are often exposed to atmospheric nanoparticles (NPs), the mechanism of NP deposition and their effects on physiology and metabolism, and particularly in combination with other stressors, are not yet understood. Exploring interactions between stressors is particularly important for understanding plant responses in urban environments where elevated temperatures can be associated with air pollution. Accordingly, 3-year-old spruce seedlings were exposed for 2 weeks to aerial cadmium oxide (CdO) NPs of environmentally relevant size (8-62 nm) and concentration (2 × 105 cm-3). While half the seedlings were initially acclimated to high temperature (35 °C) and vapour pressure deficit (VPD; 2.81 kPa), the second half of the plants were left under non-stressed conditions (20 °C, 0.58 kPa). Atomic absorption spectrometry was used to determine Cd content in needles, while gas and liquid chromatography was used to determine changes in primary and secondary metabolites. Photosynthesis-related processes were explored with gas-exchange and chlorophyll fluorescence systems. Our work supports the hypothesis that atmospheric CdO NPs penetrate into leaves but high temperature and VPD reduce such penetration due to stomatal closure. The hypothesis that atmospheric CdO NPs influences physiological and metabolic processes in plants was also confirmed. This impact strengthens with increasing time of exposure. Finally, we found evidence that plants acclimated to stress conditions have different sensitivity to CdO NPs compared to plants not so acclimated. These findings have important consequences for understanding impacts of global warming on plants and indicates that although the effects of elevated temperatures can be deleterious, this may limit other forms of plant stress associated with air pollution.
- Simultaneous determination of phenolic acids and flavonoids in Artemisiae Argyi Folium by HPLC-MS/MS and discovery of antioxidant ingredients based on relevance analysis. [Journal Article]
- JPJ Pharm Biomed Anal 2019 Jul 05; 175:112734
- A rapid and reliable LC-MS/MS method was developed for the quantitation of major components in Folium Artemisiae Argyi (mugwort), a widely used traditional Chinese herbal medicine. A total of 5 pheno…
A rapid and reliable LC-MS/MS method was developed for the quantitation of major components in Folium Artemisiae Argyi (mugwort), a widely used traditional Chinese herbal medicine. A total of 5 phenolic acids and 17 flavonoids were separated and simultaneously determined by using a Shiseido C18 column (150 × 3.0 mm, 3 μm) and gradient elution of acetonitrile-aqueous formic acid (100:0.1, v/v) at a 0.5 mL min-1 flow rate, via multiple reaction monitor (MRM) in polarity switching mode. The quantitative method was validated in terms of sensitivity, linearity, precision, accuracy and stability, which proved to be sensitive, accurate and reproducible. Then 65 samples collected from different areas were selected for component analysis by LC-MS/MS and assessment of antioxidant activity using DPPH, ABTS, FRAP, O2- and OH scavenging assays. Grey relational analysis and partial least square regression were used to evaluate the relevance between chemicals and bioactivities, and the results indicated chlorogenic acid, isochlorogenic acid B, A, C, eriodictyol, jaceosidin and eupatilin made the key contribution to antioxidant activity. The present study combines chemical analysis and bioassay to identify bioactive markers, which possesses potential value for the activity-oriented quality control of mugwort.
- Analysis of impurities of cannabidiol from hemp. Isolation, characterization and synthesis of cannabidibutol, the novel cannabidiol butyl analog. [Journal Article]
- JPJ Pharm Biomed Anal 2019 Jul 12; 175:112752
- Cannabidiol (CBD), one of the two major active principles present in Cannabis sativa, is gaining great interest among the scientific community for its pharmaceutical, nutraceutical and cosmetic appli…
Cannabidiol (CBD), one of the two major active principles present in Cannabis sativa, is gaining great interest among the scientific community for its pharmaceutical, nutraceutical and cosmetic applications. CBD can be prepared either by chemical synthesis or extraction from Cannabis sativa (hemp). The latter is more convenient from several points of view, including environmental and economic, but mainly for the absence of harmful organic solvents generally employed in the chemical synthesis. Although CBD produced by hemp extraction is the most widely employed, it carries two major impurities. The first one is the already known cannabidivarin (CBDV), whereas the second one is supposed to be the butyl analog of CBD with a four-term alkyl side chain. In this work, we report the isolation by semi-preparative liquid chromatography and the unambiguous identification of this second impurity. A comprehensive spectroscopic characterization, including NMR, UV, IR, circular dichroism and high-resolution mass spectrometry (HRMS), was carried out on this natural cannabinoid. In order to confirm its absolute configuration and chemical structure, the stereoisomer (1R,6R) of the supposed cannabinoid was synthesized and the physicochemical and spectroscopic properties, along with the stereochemistry, matched those of the natural isolated molecule. According to the International Nonproprietary Name, we suggested the name of cannabidibutol (CBDB) for this cannabinoid. Lastly, an HPLC-UV method was developed and validated for the qualitative and quantitative determination of CBDV and CBDB in samples of CBD extracted from hemp and produced according to Good Manufacturing Practices regulations for pharmaceutical and cosmetic use.
- Characterization of unknown impurities in Coenzyme Q10 using LC-MS and NMR. [Journal Article]
- JPJ Pharm Biomed Anal 2019 Jul 14; 175:112771
- During studies on related substances in coenzyme Q10 (CoQ10) active pharmaceutical ingredient (API) and capsules, two impurities (Impurity 1 and Impurity 2) with each content more than 0.1% attracted…
During studies on related substances in coenzyme Q10 (CoQ10) active pharmaceutical ingredient (API) and capsules, two impurities (Impurity 1 and Impurity 2) with each content more than 0.1% attracted our attention. Accelerated testing (40 °C /75%RH) and forced degradation of CoQ10 API and drug products in different stress conditions (base and heat) gave rise to the two unknown impurities. These unknown impurities were separated by reverse phase ultra-performance liquid chromatography (UPLC), where they were eluted at 0.77 (Impurity 1) and 1.10 (Impurity 2) relative retention times to CoQ10 peak. Impurity 2 was separated into two peaks (Impurity 2-1 and Impurity 2-2) by normal phase high performance liquid chromatography (NP-HPLC). In this study, an ultra-performance liquid chromatography complied with quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF/MS) via atmospheric pressure chemical ionization (APCI) was used to identify the proposed structure of the three impurities (Impurity 1, Impurity 2-1 and Impurity 2-2). We got the three impurities through preparative high performance liquid chromatography and their structures were further confirmed by 1D and 2D nuclear magnetic resonance (NMR). Based on the significance of these results, Impurity 1 was the impurity E referred in British Pharmacopoeia (BP), Impurity 2-1 and Impurity 2-2 were a pair of isomers which had not been reported before.
- One-pot preparation of zwitterionic sulfoalkylbetaine monolith for rapid and efficient separation of lysozyme from egg white. [Journal Article]
- JPJ Pharm Biomed Anal 2019 Jul 08; 175:112761
- A porous zwitterionic monolithic column was prepared to rapidly and efficiently separate lysozyme from egg white. The monolith was synthesized in a stainless steel HPLC column (5 cm × 4.6 mm i.d.) by…
A porous zwitterionic monolithic column was prepared to rapidly and efficiently separate lysozyme from egg white. The monolith was synthesized in a stainless steel HPLC column (5 cm × 4.6 mm i.d.) by in-situ thermal initiated co-polymerization of N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl) ammonium betaine (MSA) and ethylene dimethacrylate (EDMA). Due to the combination of quaternary ammonium and sulfonic groups on the monolithic matrix in one-pot process, the hydrophobic carbon chain and hydrophilic radical were obtained, which provided multiple driving forces for neutral, basic and acidic analytes, thus mix-mode chromatography mechanism contributed to the retention of different charged proteins. Properties such as composition, morphology and stability of the MSA-co-EDMA monolithic column were characterized by various analytical methods and the results showed that the monolith has large through-pores, good hydrophilicity and permeability. The effects of mobile phase pH and ionic strength on proteins were investigated, drawing the conclusion that the main adsorption and elution mechanism of lysozyme on MSA-co-EDMA monolith was electrostatic interaction, while those of other proteins included hydrophobic, hydrophilic and electrostatic interactions. Therefore, efficient separation of lysozyme and other proteins could be successfully achieved by switching the pH of mobile phase. Lysozyme can be adsorbed using 20 mmol/L phosphate buffer (pH 7.0) and eluted with 20 mmol/L phosphate buffer (pH 2.0). To prove the practicality of the monolithic column, it was also applied in the separation of lysozyme in egg white, which means the work has the potential for further development in proteome analysis of real biological samples.
- An improved 2D-HPLC-UF-ESI-TOF/MS approach for enrichment and comprehensive characterization of minor neuraminidase inhibitors from Flos Lonicerae Japonicae. [Journal Article]
- JPJ Pharm Biomed Anal 2019 Jul 06; 175:112758
- Flos Lonicerae Japonicae(Jinyinhua) possesses clearing heat and detoxification activity, and has been used as a traditional Chinese medicine to treat influenza for many years. Due to the complex chem…
Flos Lonicerae Japonicae(Jinyinhua) possesses clearing heat and detoxification activity, and has been used as a traditional Chinese medicine to treat influenza for many years. Due to the complex chemical composition and diverse content of Jinyinhua, especially the many trace ingredients, the effective components are unknown. In this study, an improved two-dimensional high performance liquid chromatography-ultrafiltration combined with electrospray ionization-time-of-flight/mass spectroscopy (ESI-TOF/MS) approach was designed and used for the enrichment, screening and characterization of minor neuraminidase inhibitors in Jinyinhua. In the first dimension, semi-prep-HPLC was employed for the preliminary separation of different polarity components and enrichment of low content components from Jinyinhua extract. In the second dimension, hydrophilic interaction liquid chromatography and reverse phase-HPLC were used to separate the different polar fractions, respectively. The fractions then underwent ultrafiltration and ESI-TOF/MS for the comprehensive screening and characterization of potential neuraminidase inhibitors. As a result, a total of 44 compounds were found to have neuraminidase inhibitory activity, and 22 of these compounds were preliminarily identified by accurate molecular weight and UV absorption data compared with standards and references. The activity of 16 of these compounds was verified by the neuraminidase inhibition assay. This study provides support for the rapid screening of minor neuraminidase inhibitors from complex natural medicines.
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- Highly sensitive HPLC-MS/MS assay for the quantitation of ondansetron in rat plasma and rat brain tissue homogenate following administration of a very low subcutaneous dose. [Journal Article]
- JPJ Pharm Biomed Anal 2019 Jul 12; 175:112766
- Ondansetron is a highly selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist that is well tolerated in the clinic. Pre-clinical studies in rats have shown interesting effects of small dos…
Ondansetron is a highly selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist that is well tolerated in the clinic. Pre-clinical studies in rats have shown interesting effects of small doses of ondansetron on cognition, behavioural sensitisation and epilepsy. However, the pharmacokinetic profile at a very low dose has not been reported, possibly because currently, there are no published analytical methods capable of quantifying trace levels of ondansetron in plasma or brain. The objective of this study was to develop and validate a highly sensitive HPLC-MS/MS assay capable of quantifying ondansetron in rat plasma and rat brain homogenate following a low subcutaneous administration of 1.0 μg/kg. Ondansetron was extracted by protein precipitation with methanol containing labeled ondansetron. The chromatography was performed on a Thermo Scientific Aquasil C18 analytical column (100 x 2.1 mm I.D., 5 μm) operating at 40 °C. The mobile phase consisted of acetonitrile and 10 mM ammonium formate pH 3 at a ratio of 30:70, respectively. The flow rate was fixed at 300 μL/min and ondansetron and the internal standard were both eluted at 2.3 min. A linear (1/x) relationship was used to perform the calibration over an analytical range from 20.0 - 10,000 pg/mL in plasma and from 2.00 to 1000 pg/mL in rat brain homogenate. The inter-batch precision and accuracy ranged from 3.7 to 4.7% and from 0.7 to 10.9% in rat plasma, respectively. The inter-batch precision and accuracy observed in rat brain was 4.5 to 6.4% and -5.1 to 4.9% respectively. The method met all requirements and the assay was suitable for the determination of the pharmacokinetic profile following a subcutaneous dose of 1.0 μg/kg body weight (BW) in rats.