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Ji Hye Kang, Ju Byeong Chae, Cheal Kim
A multi-functional chemosensor 1 as silver and sulfide detector was synthesized by the combination of octopamine and 4-dimethylaminocinnamaldehyde. Sensor 1 exhibited a ratiometric fluorescence emission for Ag+ from blue to sky. The binding mode of 1 and Ag+ turned out to be a 1 : 1 ratio as determined using Job plot and electrospray ionization (ESI) mass spectral analyses. The sensing mechanism of 1 with silver ion was unravelled by 1 H NMR titrations and theoretical calculations. Sensor 1 also discerned sulfide by enhancing fluorescence intensity and changing colour from yellow to colourless in aqueous solution...
June 2018: Royal Society Open Science
Guillermo Moreiras, José Manuel Leão, Ana Gago-Martínez
Liquid Chromatography (LC) coupled to Mass Spectrometry (MS) is being widely applied as analytical tool in the field of marine biotoxins both for regulated and for new and emerging compounds. LC-MS/MS recently became the reference method for the control of lipophilic toxins in the European Union and new methods are being developed and optimized to extend the applicability of this technique to other toxin groups. In this work, conditions for the analysis of ciguatoxins (CTXs) by LC-MS/MS were investigated using standard solutions of CTX1B and CTX3C, which are structurally representative compounds for the rest of the main congeners of Pacific group toxins (P-CTXs)...
August 14, 2018: Journal of Mass Spectrometry: JMS
Aiyuan Ma, Xuemei Zheng, Song Li, Yihong Wang, Shan Zhu
Metallurgical slag and dust (MSD) from lead and zinc smelting, steel dust and galvanized steel scrap are important secondary sources of zinc and other valuable metals. This paper describes the production feasibility and rationality of a cleaner zinc recovery process using MSD and a hydrometallurgical method. It was found that the addition of CH3 COONH4 to a NH3 -H2 O system promotes zinc extraction, and 83.76% of zinc could be dissolved and recovered from the MSD under the following conditions: total ammonia concentration of 5 mol l-1 , stirring speed of 300 r...
July 2018: Royal Society Open Science
Jens Madsen, Madhurban H Panchal, Rose-Marie Mackay, Mercedes Echaide, Grielof Koster, Giancarlo Aquino, Nicola Pelizzi, Jesus Perez-Gil, Fabrizio Salamone, Howard W Clark, Anthony D Postle
Secreted pulmonary surfactant phosphatidylcholine (PC) has a complex intra-alveolar metabolism involving uptake and recycling by alveolar type II epithelial cells, catabolism by alveolar macrophages and loss up the bronchial tree. Here we compared the metabolism in vivo in adult mice of animal-derived Poractant alpha (Curosurf) and a synthetic surfactant (CHF5633). Adult male C57BL/6 were dosed intra-nasally with either surfactant (80 mg/kg body weight) containing as tracer universally 13C- labelled dipalmitoyl PC (U13C-DPPC)...
August 14, 2018: Journal of Lipid Research
Mariana Machado Matos, Renan Arthur Bosio-Guimarães, Ana Júlia Schmidt Niederauer, Katia Isabel Fercondini Pastre, Ronilson A Moreno, Simone Grigoletto Schramm, Paulo Alexandre Rebelo Galvinas, Gustavo D Mendes, Gilberto De Nucci
Capecitabine is a prodrug and is selectively activated by tumor cells to its cytotoxic moiety, 5-fluorouracil, by thymidine phosphorylase, which is generally expressed at high levels in tumors. Clinical and pharmacokinetic studies of capecitabine have been performed in patients with cancer. This study aims to evaluate the bioequivalence of two capecitabine formulations (150-mg tablet) using healthy male subjects under nonfasting conditions. The study was conducted as an open, randomized, three-period, semi-replicated design with three sequences (RRT, RTR, TRR) with a 1-week washout interval...
August 14, 2018: International Journal of Clinical Pharmacology and Therapeutics
M H Blokland, P W Zoontjes, L A Van Ginkel, M G M Van De Schans, S S Sterk, T F H Bovee
Nowadays routine residue monitoring involves the analysis of many compounds from different classes, mainly in urine. In the past two decades, developments heavily focused on the use of mass spectrometers (MS) and faster and more sensitive MS detectors have reached the market. However, chromatographic separation (CS) was rather ignored and the cognate developments in CS were not in line. As a result, residue analysis did not improve to the extent anticipated. CS by LC x LC is a promising technique and will enable a further increase in the range of compounds and compound classes that can be detected in a single run...
August 14, 2018: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Dongsheng Fan, Ting Li, Zhiyuan Zheng, Guo-Yuan Zhu, Xiaojun Yao, Zhi-Hong Jiang, Li-Ping Bai
Nine new monomacrolide sesquiterpene pyridine alkaloids, macroregelines A-I (1-9), were isolated from the stems of Tripterygium regelii, along with a known alkaloid, tripfordine B. The structures of all the isolated compounds were characterized by extensive one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopic analyses, as well as high-resolution electrospray-ionization mass spectrometry (HRESIMS) data. Compounds 4, 5, 6, and 8 showed antiproliferative effect on human rheumatoid arthritis synovial cell line MH7A at concentration of 20 μM, reducing their viability by 7...
August 13, 2018: Journal of Natural Medicines
Nastaran Kadivar, Hossein Tavanai, Alireza Allafchian
This study reports the fabrication of cellulose nanoparticles through electrospraying the solution of cellulose in N,N -dimethylacetamide/lithium chloride solvent as well as investigating the effect of electrospraying conditions and molecular weight on the average size of electrosprayed nanoparticles. Electrospraying of cellulose was carried out with the following range for each factor, namely concentration = 1-3 wt%, voltage = 15-23 kV, nozzle-collector distance = 10-25 cm, and feed rate = 0...
September 2018: IET Nanobiotechnology
Xue-Qin Song, Cai-Yun Wang, Huan-Huan Meng, Ali Alhafeez Abdulrheem Shamshoom, Wei-Sheng Liu
Five heterometallic ZnII 6 -LnIII 3 macrocycles based on a salicylamide imine multidentate unsymmetrical ligand H2 L [1-(2-hydroxy-3-methoxy-benzamido)-2-(2-hydroxy-3-methoxy-benzylideneamino)-ethane] have been prepared via a coordination-driven self-assembly strategy. Single-crystal X-ray diffraction analysis reveals that the five metallocycles are isomorphic with a formula of [Zn6 Ln3 L6 (OH)2 (NO3 )4 (H2 O)]·3NO3 · nCH3 CN (ZnLn-1, where Ln = Pr, Nd, Eu, Tb, or Yb; for ZnPr-1, n = 4; for ZnNd-1, ZnEu-1, and ZnTb-1, n = 2; for ZnYb-1, n = 3), where six octadentate ligands L2- and two in situ-formed μ2 -OH- ions bridged the alternating ZnII -LnIII -ZnII subunits into a macrocycle...
August 13, 2018: Inorganic Chemistry
Fuguo Shi, Hong Pan, Yuanfu Lu, Li Ding
A selective and accurate HPLC-MS/MS method was established to simultaneously quantify luteolin and its active metabolites (diosmetin, chryseriol and luteolin-7-O-glucuronide) in rat plasma. The analytes were separated on a C18 column with a mobile phase of water containing 0.5% formic acid and acetonitrile under gradient elution to shorten the total chromatographic run time and increase the resolution of diosmetin and chryseriol. A triple quadruple mass spectrometer coupled with an electrospray ionization source in the negative ion mode was used to detect the analytes...
August 12, 2018: Journal of Separation Science
Richard Broughton, Noemi Ruíz-Lopez, Kirsty L Hassall, Enrique Martínez-Force, Rafael Garcés, Joaquín J Salas, Frédéric Beaudoin
Wax esters (WEs) and steryl esters (SEs) are minor components of sunflower oils formed by the esterification of long chain fatty alcohols and sterols to fatty acids. These compounds have similar carbon numbers and polarities making them difficult to separate using conventional chromatographic methods. In this study, electrospray ionisation-tandem mass spectrometry (ESI-MS/MS) allowed the rapid and accurate profiling of WEs and SEs acyl moieties in total ester fractions of common and mutant sunflower oils with different fatty acid profiles...
December 15, 2018: Food Chemistry
Daimon Syukri, Manasikan Thammawong, Hushna Ara Naznin, Shinichiro Kuroki, Mizuki Tsuta, Makoto Yoshida, Kohei Nakano
The objective of this study was to identify metabolites that quantitatively indicate degrees of freshness of soybean sprouts. Self-cultivated soybean sprouts were stored at 5 °C, 10 °C or 20 °C, and respiratory CO2 production rates were monitored using gas chromatography during storage. Carbonyl compounds (CCs) were analyzed comprehensively using mass-spectroscopic metabolomics analyses. CCs were derivatized using dansyl hydrazine (DH) and were then analyzed using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-MS/MS) with multiplexed multiple reaction monitoring (MRM)...
December 15, 2018: Food Chemistry
Xing Xie, Bo Wang, Maoda Pang, Xia Zhao, Kaizhou Xie, Yangyang Zhang, Ya'juan Wang, Ya'wen Guo, Chu'jun Liu, Xiao'na Bu, Ran Wang, Huiqiang Shi, Genxi Zhang, Tao Zhang, Guojun Dai, Jinyu Wang
A widely applicable method involving liquid chromatography-electrospray ionization tandem triple quadrupole mass spectrometry (LC-ESI/MS/MS) was developed for the simultaneous determination of chloramphenicol, thiamphenicol, florfenicol, and florfenicol amine in eggs. Samples were extracted with ethyl acetate-acetonitrile-ammonium hydroxide (49:49:2, v/v) and defatted with hexane saturated with acetonitrile. The analysis was carried out on a mass spectrometer via an electrospray interface operated in the positive and negative ionization modes using deuterated chloramphenicol-d5 as the internal standard...
December 15, 2018: Food Chemistry
Tajudheen K Karatt, Jahfar Nalakath, Zubair Perwad, Peter H Albert, K K Abdul Khader, M Syed Ali Padusha, S Laya
The major challenge in identifying dexamethasone, betamethasone, and paramethasone from a mixture of these corticosteroids is difficulty in achieving an efficient separation. In this study, we aimed to develop an efficient technique to identify these co-eluting isomers based on the mass spectral patterns of them and their corresponding phase II metabolites after electrospray ionization. Fragmentation pathways in tandem mass spectrometry revealed acceptable specificity within the groups of conjugates. The method was validated using individual isomers and mixtures at various compositions...
August 11, 2018: Journal of Mass Spectrometry: JMS
Lingzhi Wang, Do-Dang Khoa Phan, Nicholas Syn, Xiaoqiang Xiang, Hongyan Song, Win Lwin Thuya, Shili Yang, Andrea Li-Ann Wong, Alan Prem Kumar, Wei Peng Yong, Gautam Sethi, Paul Chi-Lui Ho, Boon Cher Goh
A sensitive and robust liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the determination of nimbolide in mouse serum. Exemestane was used as the internal standard (IS). Here, we employed acetonitrile-based protein precipitation (PPT) for serum sample preparation, and performed chromatographic separation using an ODS Hypersil C18 column (100 mm × 2.1 mm, 5 µm) with gradient elution (0.1% formic acid in water vs 100% acetonitrile). The run time was 6 min. Instrumental analysis was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) in the multiple-reaction monitoring (MRM) under positive mode...
August 8, 2018: Pharmaceutics
Huijuan Yu, Jing Yang, Jiamin Ding, Ying He, Zhenzuo Jiang, Xin Chai, Yuefei Wang
Caffeoylgluconic acid derivatives are characteristic constituents isolated from the aqueous extract of Fructus Euodiae. In this research focusing on caffeoylgluconic acid derivatives, trans -caffeoyl-6- O -d-gluconic acid (CGA), trans -caffeoyl-6- O -d-gluconic acid methyl ester (CGA-ME), and trans -caffeoyl-6- O -d-glucono- γ -lactone (CGA-LT), a systematic study of stability was performed under different temperatures and pH levels by ultra performance liquid chromatography-diode array detector (UPLC-DAD) and ultra performance liquid chromatography-diode array detector/electrospray ionization-quadrupole-time of flight mass spectrometry (UPLC-DAD/ESI-Q-TOF MS)...
August 8, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Hyun-Jae Jang, Eun-Jae Park, Seung-Jae Lee, Hyung-Jin Lim, Jin Ha Jo, Seung Woong Lee, Mun-Chual Rho
Three undescribed diarylheptanoids (3: -5: ) and six known curcuminoids (1, 2: , and 6: -9: ) were obtained from the ethyl acetate-soluble fraction of an ethanolic extract of Curcuma phaeocaulis . Their chemical structures and absolute configurations were elucidated by high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopy, circular dichroism spectroscopy, and the modified Mosher's method. Previous studies constructed Hep3B cells stably transfected with pSTAT3-Luc plasmid containing STAT3 binding site to discover STAT3 inhibitors from natural products...
August 10, 2018: Planta Medica
Nora Gibitz-Eisath, Miriam Eichberger, Regina Gruber, Sonja Sturm, Hermann Stuppner
This study presents a fast and validated ultra-high performance liquid chromatography diode array detector (UHPLC-DAD) method for the simultaneous determination of the major compounds in Verbena officinalis L. (Verbenaceae), a medicinal plant listed in the European, British, and, Chinese Pharmacopoeias. In order to get reference substances, nine compounds, belonging to iridoids, flavonoids, and phenylpropanoid glycosides, were isolated from the herb extract. Two of them, namely cistanoside D and leucosceptoside A, were found in this plant species for the first time...
July 27, 2018: Journal of Pharmaceutical and Biomedical Analysis
F Mashayeky Rad, S Spinicci, S Silvergren, U Nilsson, R Westerholm
In the present study, a methodology involving hydrophilic interaction liquid chromatography (HILIC) and electrospray (ESI) tandem mass spectrometry (MS/MS) was developed for measurement of anhydrous monosaccharides as markers for wood burning in atmospheric aerosols, PM10 . No extensive sample preparation, other than ultrasound-assisted solvent extraction and evaporation, was applied. A pentahydroxysilica column enabled separation of levoglucosan from mannosan and galactosan within 5 min and the quantitative performance was validated using the standard reference materials (SRM) 1649a and 1649b...
August 1, 2018: Chemosphere
Khalid Mahmood, Arshi Khalid, Faisal Nawaz, Muhammad Taqi Mehran
Semiconducting metal oxide electron transporting layers (ETLs) with distinct morphologies have the ability to produce the less-hysteric and high efficiency perovskite solar cells (PSCs). Here, for the first time we introduce a viable electrospraying route for one-step deposition of highly mesoporous SnO2 nanosheets, as the ETLs in PSCs with reduces hysteresis, high charge collection efficiency and improved ambient stability. Furthermore, optimization of the interfacial properties between the SnO2 nanosheets and the perovskite absorber layer by the employment of a C60 interlayer consequences in decreasing the charge recombination, better energy level alignment, and significantly improved power conversion efficiency (PCE)...
August 6, 2018: Journal of Colloid and Interface Science
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