high resolution mass spectrum
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2021 ◽  
Vol 76 (14) ◽  
pp. 1645-1650
Author(s):  
A. V. Braun ◽  
M. F. Vokuev ◽  
Y. V. Stavitskaya ◽  
T. M. Baygildiev ◽  
V. A. Yashkir ◽  
...  




2021 ◽  
Vol 19 (4) ◽  
pp. 257-264
Author(s):  
Xin Xin ◽  
Zhilan Chen ◽  
Chun Zhang ◽  
Qinhua Zhang ◽  
Xiaoji Hu

The synthesis and characterization of new pyran derivatives (1–3) were realized by means of infrared spectroscopy (IR), 1H nuclearmagnetic resonance spectroscopy (1H NMR), high resolution mass spectrum (HRMS) and single crystal X-ray crystallography. The anti-proliferation activity of compounds 1–3 was investigated against human ovarian cancer cells CAOV3 by Cell Counting Kit-8 (CCK-8) assay. The RT-PCR assay was performed to detect the relative expression level of the Foxm1b in the CAOV3 cell line after treated with compounds 1–3. Furthermore, molecular docking studies supported the biological assay data and suggested that compared with compounds 1 and 3, compound 2 has stronger interaction with protein.



Author(s):  
Vo Viet Dai Vo

1,5-Disubstituted 1,2,3-triazoles are synthesized viametal-free multi-component reaction from primary amine, ketones and 4-nitrophenyl azide. The structure of three target compounds including:1-(4-methoxybenzyl)-5-(4-methylphenyl)-1H-1,2,3-triazole (1), 1-(4-methoxybenzyl)-5-(4-nitrophenyl)-1H-1,2,3-triazole (2) and 1-(4-methoxybenzyl)-5-phenyl-1H-1,2,3-triazole (3) is elucidated and identified by infrared spectroscopy, nuclear magnetic resonance spectroscopic analysis and high resolution mass spectrum. The formation of heterocyclic aromatic 1,2,3-triazole ring is approved by the appearance of singlet peak at 7.71 ppm in 1H NMR corresponding with triazolyl proton. In addition, antibacterial and antifungal activities of products are also tested with three Gram-positive bacteria (B. subtilis, S. aureus and L. fermentum), three Gram-negative bacteria (P. aeruginosa, E.coli, S. enterica), and Candida albicans fungus.



2020 ◽  
Vol 16 ◽  
Author(s):  
Liang-hong Liu ◽  
Jie Peng ◽  
Si-lin Shi ◽  
Kai-lin Li ◽  
Pei Xiong ◽  
...  

Background: Lithocarpus litseifolius (Hance) Chun (L. litseifolius) has been used for treating diabetes, allergic, inflammatory and hyperlipidemia in folk medicine. Previous studies have shown that the main active ingredient of its leaves are flavonoids. However, as far as we are aware, the stem of L. litseifolius have not been investigated. Some of stem fall down from the plant every year, while it was considered as a waste due to limited knowledge of this stem, which cause the waste of plant resource. Therefore, it is necessary to investigate the chemical of the stem, which will be beneficial for the development and utilization of the stem. Methods: In this study, the dry twigs of L. litseifolius were powdered and extracted at first. Then, the sample was performed on UHPLC-Q-Exactive Orbitrap MS in negative mode combined with Parallel reaction monitoring scanning to gain the high resolution mass spectrum, which was processed by Compound Discover version 3.0 using high resolution extracted ion chromatography and expected compounds predicted. Result: A total of 35 flavonoids including flavone, flavonol, dihydroflavone, isoflavone, dihydrochalcone were putatively identified based on their accurate mass measurement, chromatographic retention, MSn spectra, and bibliography data. Conclusion: In this study, all of those flavonoids was identified from stems of L. litseifolius for the first time, and 5 of those constituents was first report from this plant, which will be very helpful for the development and utilization of the stem of L. litseifolius.



Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Haicheng She ◽  
Debin Kong ◽  
Yiqiang Li ◽  
Zaiqiang Hu ◽  
Hu Guo

Compared with other enhanced oil recovery (EOR) techniques like gas flooding, chemical flooding, and thermal production, the prominent advantages of microbial enhanced oil recovery (MEOR) include environment-friendliness and lowest cost. Recent progress of MEOR in laboratory studies and microbial flooding recovery (MFR) field tests in China are reviewed. High biotechnology is being used to investigate MFR mechanisms on the molecular level. Emulsification and wettability alternation due to microbial effects are the main interests at present. Application of a high-resolution mass spectrum (HRMS) on MEOR mechanism has revealed the change of polar compound structures before and after oil degradation by the microbial on the molecular level. MEOR could be divided into indigenous microorganism and exogenous microorganism flooding. The key of exogenous microorganism flooding was to develop effective production strains, and difficulty lies in the compatibility of the microorganism, performance degradation, and high cost. Indigenous microorganism flooding has good adaptation but no follow-up process on production strain development; thus, it represents the main development direction of MEOR in China. More than 4600 wells have been conducted for MEOR field tests in China, and about 500 wells are involved in MFR. 47 MFR field tests have been carried out in China, and 12 field tests are conducted in Daqing Oilfield. MFR field test’s incremental oil recovery is as high as 4.95% OOIP, with a typical slug size less than 0.1 PV. The input-output ratio can be 1 : 6. All field tests have shown positive results in oil production increase and water cut reduction. MEOR screening criteria for reservoirs in China need to be improved. Reservoir fluid, temperature, and salinity were the most important three parameters. Microbial flooding technology is mature in reservoirs with temperature lower than 80°C, salinity less than 100,000 ppm, and permeability above 5 mD. MFR in China is very close to commercial application, while MFR as quaternary recovery like those in post-polymer flooding reservoirs needs further study.



2015 ◽  
Vol 8 (6) ◽  
pp. 5735-5768 ◽  
Author(s):  
S. Carbone ◽  
T. Onasch ◽  
S. Saarikoski ◽  
H. Timonen ◽  
K. Saarnio ◽  
...  

Abstract. A method to detect and quantify mass concentrations of metals by the Aerodyne Soot Particle – Aerosol Mass Spectrometer (SP-AMS) was developed and evaluated in this study. The generation of monodisperse Regal black (RB) test particles with trace amounts of 13 different metals (Na, Al, Ca, V, Cr, Fe, Mn, Ni, Cu, Zn, Rb, Sr and Ba) allowed the determination of the relative ionization efficiency of each metal (RIEmeas). The ratio RIEtheory / RIEmeas presented values larger than the unity for Na, Rb, Ca, Sr and Ba due to the thermal surface ionization (TSI) on the surface of the RB particles. Values closer to the unity were obtained for the transition metals Zn, Cu, V and Cr. Mn, Fe and Ni presented the lowest RIEtheory / RIEmeas ratio and highest deviation from the unity, which was most likely related to different losses. The RIEmeas values obtained in this study were applied to the data of emission measurements in a heavy fuel oil fired heating station. Emission measurements revealed various fragmentation patterns for sulfate, probably because sulfate was mainly in the form of metallic salts (vanadium sulfate, calcium sulfate, iron sulfate and barium sulfate), which were also identified in the high-resolution mass spectrum. The response of the metals to the laser power was also investigated and the results indicated that a minimum current of 0.6 A was needed in the laser in order to vaporize the metals and the rBC. Isotopic pattern of metals was resolved from high-resolution mass spectra and the mass size distribution information of each individual ion was obtained using the high-resolution particle time-of-flight (HR-PToF).



Author(s):  
QING M. WEI ◽  
XING Z. LI ◽  
BIN LIU ◽  
N. MUELLER ◽  
P. SCHOCH ◽  
...  


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