scholarly journals Characterization of MK8(H2) from Rhodococcus sp. B7740 and Its Potential Antiglycation Capacity Measurements

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 391 ◽  
Author(s):  
Yashu Chen ◽  
Qin Mu ◽  
Kai Hu ◽  
Mo Chen ◽  
Jifang Yang ◽  
...  
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Resolution Mass Spectrometry ◽  
Extraction Process ◽  
The Arctic ◽  
Human Metabolism ◽  
Ubiquinone Q10 ◽  
First Time ◽  
Rhodococcus Sp

Menaquinone (MK) has an important role in human metabolism as an essential vitamin (VK2), which is mainly produced through the fermentation of microorganisms. MK8(H2) was identified to be the main menaquinone from Rhodococcus sp. B7740, a bacterium isolated from the arctic ocean. In this work, MK8(H2) (purity: 99.75%) was collected through a convenient and economic extraction process followed by high-speed countercurrent chromatography (HSCCC) purification. Additionally, high-resolution mass spectrometry (HRMS) was performed for further identification and the hydrogenation position of MK8(H2) (terminal unit) was determined using nuclear magnetic resonance (NMR) for the first time. MK8(H2) showed a superior antioxidant effect and antiglycation capacity compared with ubiquinone Q10 and MK4. High-performance liquid chromatography–mass spectrometer (HPLC-MS/MS) and molecular docking showed the fine interaction between MK8(H2) with methylglyoxal (MGO) and bull serum albumin (BSA), respectively. These properties make MK8(H2) a promising natural active ingredient with future food and medicine applications.

Characterization of Rotating Cavitation in a High Speed Inducer of Liquid Rocket Engine

2011 ◽  
Vol 320 ◽  
pp. 196-201
Author(s):  
Fei Tang ◽  
Li Jia Wen
Keyword(s):  
High Speed ◽  
High Performance ◽  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Blade Surface ◽  
Cavitation Phenomenon ◽  
Flow Fluctuations ◽  
Blade Cascade ◽  
Liquid Rocket

Rotating cavitation is one of the most important problems in the development of modern high performance rocket pump inducers. In this paper, a numerical simulation of rotating cavitation phenomenon in a 2D blade cascade of liquid rocket engine inducer was carried out using a mixture model based on Rayleigh-Plesset equation. The purpose is to investigate the characterization of rotating cavitation in a high speed inducer. The results show that when sub-synchronous rotating cavitation occurs, the speed for the length of the blade surface cavitation is lower than the speed frequency of rotation shaft with the same direction. The external aspect is that the pressure at the upstream of blades changes synchronous. Thus, the generation of sub-synchronous rotating cavitation is closely related to the changes of flow angel which caused by the flow fluctuations. Hence, elimination of the flow rate redistribution among the flow channel can effectively suppress the occurrence of this phenomenon.

Synthesis and characterization of meso-to-meso directly linked porphyrin-diazaporphyrin triads

2018 ◽  
Vol 22 (09n10) ◽  
pp. 814-820
Author(s):  
Yingying Jia ◽  
Ling Xu ◽  
Bangshao Yin ◽  
Mingbo Zhou ◽  
Jianxin Song
Keyword(s):  
Nickel Complex ◽  
High Resolution Mass Spectrometry ◽  
Dihedral Angles ◽  
X Ray Diffraction ◽  
Extinction Coefficients ◽  
X Ray ◽  
H Nmr ◽  
First Time ◽  
Molar Extinction Coefficients

Beginning with 5,10,15-triarylporphyrin-nickel complex, five meso-to-meso directly linked porphyrin-diazaporphyrin triads were successfully prepared for the first time through a series of reactions including formylation via Vilsmeier–Haack reaction, condensation with pyrrole, bromination with [Formula: see text]-Bromosuccinimide (NBS), oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), metal-templated cyclization of dibromodipyrrin-metal complexes with NaN[Formula: see text] and demetalization. All these triads were comprehensively characterized by [Formula: see text]H NMR, high-resolution mass spectrometry and UV-vis absorption. In addition, the structure of compound 6Ni was unambiguously determined by X-ray diffraction analysis, which showed that the two dihedral angles are both 86.65 (4)[Formula: see text] between each mean plane of porphyrin and that of central diazaporphyrin The UV-vis absorption spectra disclosed that the longest wavelengths of Soret bands and Q bands for these triads were observed at 429 and 642 nm, respectively. In contrast to diazaporphyrin-porphyrin dyads, diazaporphyrin dimers and diazaporphyrin monomers reported previously the molar extinction coefficients, particularly for triad 8Ni are much higher.

scholarly journals High performance liquid chromatography coupled with high resolution mass spectrometry-based characterization of lipidomic responses from rats with kidney injuries

RSC Advances ◽  
2018 ◽  
Vol 8 (36) ◽  
pp. 20250-20258
Author(s):  
Qun Liang ◽  
Han Liu ◽  
Xiuli Li ◽  
Yang Zhang
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Lipid Metabolism ◽  
High Resolution ◽  
High Performance ◽  
High Resolution Mass Spectrometry ◽  
High Resolution Mass ◽  
Resolution Mass

In this study, we present targeted and non-targeted lipidomics strategies to discover the lipid metabolism variation in serum in rats with sepsis-induced kidney injuries.

Development and Evaluation of a High-Speed Continuous-Flow Analyzer

1972 ◽  
Vol 18 (9) ◽  
pp. 1013-1018
Author(s):  
M A Evenson ◽  
M A Olson
Keyword(s):  
Continuous Flow ◽  
High Speed ◽  
High Performance ◽  
Operating Characteristics ◽  
Raw Data ◽  
Automatic Computer ◽  
Carry Over ◽  
First Time

Abstract A high-speed, high-performance, continuous-flow analyzer is described that operates at two to three times the usual analysis rate without necessitating corrections of the raw data and with no decrease in accuracy or precision. At faster speeds (180-300 samples/h) inductive sample interaction (%Ii), opposite in direction to carry-over, is for the first time quantitatively measured. A correction equation for %Ii was developed, and when it is applied to raw data, the accuracy of the results are significantly improved. Operating characteristics of the high-speed analyzer are described and the desirability of automatic computer corrections is discussed for the high-speed system.

scholarly journals Rapid Screening and Structural Characterization of Antioxidants from the Extract ofSelaginella doederleiniiHieron with DPPH-UPLC-Q-TOF/MS Method

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Gang Wang ◽  
Shun Yao ◽  
Xiu-Xiu Zhang ◽  
Hang Song
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Rapid Screening ◽  
Flight Mass Spectrometry ◽  
First Time ◽  
Strong Capacity ◽  
Tof Ms

2,2-Diphenyl-1-picrylhydrazyl-ultra-high performance liquid chromatography-Q-time-of-flight mass spectrometry (DPPH-UPLC-Q-TOF/MS), as a rapid and efficient means, now was used for the first time to screen antioxidants fromSelaginella doederleinii. The nine biflavone compounds were screened as potential antioxidants. The biflavones were structurally identified and divided into the three types, that is, amentoflavone-type, robustaflavone-type, and hinokiflavone-type biflavonoids. Among the compounds bilobetin (3) and putraflavone (8) were found fromSelaginella doederleiniifor the first time and others including amentoflavone (1), robustaflavone (2), 4′-methoxy robustaflavone (4), podocarpusflavone A (5), hinokiflavone (6), ginkgetin (7), and heveaflavone (9) were identified previously in the plant. Moreover, nine biflavones possessed a good antioxidant activity via their DPPH free radical scavenging. It demonstrates that DPPH-UPLC-Q-TOF/MS exhibits strong capacity in separation and identification for small molecule. The method is suitable for rapid screening of antioxidants without the need for complicated systems and additional instruments.

Characterization of phenolic compounds from inner bark of Betula pendula

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Jaana Liimatainen ◽  
Maarit Karonen ◽  
Jari Sinkkonen ◽  
Marjo Helander ◽  
Juha-Pekka Salminen
Keyword(s):  
Phenolic Compounds ◽  
High Performance ◽  
Betula Pendula ◽  
Silver Birch ◽  
Biologically Active ◽  
Array Detector ◽  
Ionization Mass ◽  
Inner Bark ◽  
First Time

Abstract A method has been developed for the characterization of biologically active silver birch (Betula pendula) inner bark phenolics based on high-performance liquid chromatography/diode array detector (HPLC-DAD)/electrospray ionization-mass spectrometry (ESI-MS). It was demonstrated that the inner bark contains high amounts of flavonoids, arylbutanoids, diarylheptanoids, simple phenolic compounds, phenolic acids, lignans, and procyanidins. Altogether, 30 individual compounds were characterized based on their ultraviolet (UV) and MS data. Structures of 22 compounds were confirmed by nuclear magnetic resonance (NMR) spectroscopy. In addition to previously reported phenolic compounds, 12 compounds were identified in silver birch inner bark for the first time; two of them are novel compounds: 3-β-glucopyranosyloxy-2-hydroxy-1-(4-hydroxy-3-methoxy-phenyl)-propan-1-one and 1,7-bis-(4-hydroxyphenyl)-3-heptanol 3-O-β-ap-iofuranosyl-(1→2)-β-glucopyranoside.

Nonvolatile resistive memories utilizing functional PES-based supramolecular film

2017 ◽  
Vol 30 (9) ◽  
pp. 1056-1063 ◽  
Author(s):  
Hejing Sun ◽  
Haibo Zhang ◽  
Zheng Chen ◽  
Jinhui Pang ◽  
Cong Gao ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
High Performance ◽  
Memory Device ◽  
Memory Devices ◽  
Resistive Switching Memory ◽  
Threshold Voltages ◽  
High Performance Polymer ◽  
Fabrication And Characterization ◽  
First Time

This study reports the fabrication and characterization of polymer resistive switching memory devices fabricated from poly(ether sulfone)s (PESs), containing carboxylic functional groups for hydrogen bonding with disperse red 1. PES-based supramolecular memory devices exhibited write-once read-many-times-type memory effects, with low switching threshold voltages below −5.0 V and high ON/OFF current ratios of 105. It is the first time that the concept of azobenzene supramolecular PES based on hydrogen bonding for electrical memory device application was investigated. A possible switching mechanism based on the charge transfer interaction was proposed through molecular simulation, optical absorption, and cyclic voltammetry. These results render the PES-based supramolecular memory devices as promising components for high-performance polymer memory devices.

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