Liquid Chromatography Quadrupole Time-Of-Flight Tandem Mass Spectrometry for Selective Determination of Usnic Acid and Application in Pharmacokinetic Study

Fang, Minfeng,Wang, Hui,Wu, Yang,Wang, Qilin,Zhao, Xinfeng,Zheng, Xiaohui,Wang, Shixiang,Zhao, Guifang Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

A rapid and sensitive method for determining usnic acid of Lethariella cladonioides in rat was established using high performance liquid chromatography (HPLC) quadrupole time-of-flight (QTOF) tandem mass (MS/MS). Rat plasma was pretreated by mixture of acetonitrile and chloroform to precipitate plasma proteins. Chromatographic separation was achieved on a column ($50{\times}2.1$ mm, $5{\mu}m$) with a mobile phase consisting of water (containing $5{\times}10^{-3}$ M ammonium formate, pH was adjusted to 3.0 with formic acid) and acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via collision induced dissociation (CID) under negative ionization mode. The MS/MS transitions monitored were m/z 343.0448 ${\rightarrow}$ m/z 313.2017 for usnic acid and m/z 153.1024 ${\rightarrow}$ m/z 136.2136 for protocatechuic acid (internal standard). The linear range was calculated to be 2.0-160.0 ng/mL with a detection limit of 3.0 pg/mL. The inter- and intra-day accuracy and precision were within ${\pm}7.0%$. Pharmacokinetic study showed that the apartment of usnic acid in vivo confirmed to be a two compartment open model. The method was fully valid and will probably be an alternative for pharmacokinetic study of usnic acid.

Chemical Composition, Antioxidant and Cytoprotective Activities of Lotus Receptacle

Weicheng Hu,Gongcheng Wang,Ting Shen,Yuning Wang,Boran Hu,Xinfeng Wang,Lei Wu,Pengxia Li,Lilian Ji 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.5

The nutritional composition (ash, protein, fat, crude fiber, and carbohydrate) and antioxidant activity of lotus receptacles (LRs) were studied. The LRs contained 88.25% carbohydrates, 22.90% crude fiber, 5.79% crude ash, 0.77% crude protein content, and 5.19% crude lipid on a dry weight basis. The ethanolic extract of lotus receptacle (ELR) exerted strong scavenging effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, hydroxyl radical (•OH), superoxide anion (O2-), and hydrogen peroxide (H2O2), as well as high reducing power. ELR pretreatment effectively elevated cell viability and decreased malondialdehyde (MDA) levels in H2O2-treated RAW 264.7 cells. Additionally, ELR had high phenolic and flavonoid contents with values of 318.15 mg gallic acid equivalent/g and 239.06 mg rutin equivalent/g, respectively. Moreover, the bioactivity-guided study of ELR resulted in the isolation and identification of quercetin-3-O-β-D-glucopyranoside (QOG), a dietary flavonoid. QOG exhibited strong DPPH free radical scavenging activity, with an IC50 value of 24.26 μM; docking studies revealed that QOC formed one hydrogen bond with LYS263 in the active site, suggesting it is, in part, responsible for the free activity of LR.

Liquid Chromatography Quadrupole Time-Of-Flight Tandem Mass Spectrometry for Selective Determination of Usnic Acid and Application in Pharmacokinetic Study

Minfeng Fang,Hui Wang,Yang Wu,Qilin Wang,Xinfeng Zhao,Xiao-Hui Zheng,Shixiang Wang,Guifang Zhao 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

A rapid and sensitive method for determining usnic acid of Lethariella cladonioides in rat was established using high performance liquid chromatography (HPLC) quadrupole time-of-flight (QTOF) tandem mass (MS/MS). Rat plasma was pretreated by mixture of acetonitrile and chloroform to precipitate plasma proteins. Chromatographic separation was achieved on a column (50 × 2.1 mm, 5 μm) with a mobile phase consisting of water (containing 5 × 10−3 M ammonium formate, pH was adjusted to 3.0 with formic acid) and acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via collision induced dissociation (CID) under negative ionization mode. The MS/MS transitions monitored were m/z 343.0448 → m/z 313.2017 for usnic acid and m/z 153.1024 → m/z 136.2136 for protocatechuic acid (internal standard). The linear range was calculated to be 2.0-160.0 ng/mL with a detection limit of 3.0 pg/mL. The inter- and intra-day accuracy and precision were within ± 7.0%. Pharmacokinetic study showed that the apartment of usnic acid in vivo confirmed to be a two compartment open model. The method was fully valid and will probably be an alternative for pharmacokinetic study of usnic acid.

The mediating role of atrial fibrillation in causal associations between risk factors and stroke: a Mendelian randomization study

Shanmei Qin(Shanmei Qin),Mengmeng Wang(Mengmeng Wang),Dipender Gill(Dipender Gill ),Zhizhong Zhang(Zhizhong Zhang),Xinfeng Liu(Xinfeng Liu) 한국역학회 2024 Epidemiology and Health Vol.46 No.-

Preparation and Properties Characterization of Interpenetrating Polymer Networks/Organically Modified Montmorillonite/Scrap Leather Fibers Composites

Xinfeng Wu,Zehui Duan,Ying Wang,Yuan Gao,Kai Sun,Runhua Fan,Xiaofeng Li 한국섬유공학회 2019 Fibers and polymers Vol.20 No.9

An interpenetrating polymer networks (IPNs) based on the anhydride-cured cycloaliphatic epoxy and the trifunctionalacrylate resin cross-linked by peroxide was modified by incorporation of organic montmorillonites (OMMTs) andscrap leather fibers (SLFs). OMMTs and SLFs were introduced into IPNs via a violently mechanical stirring technique whichprovided a very well-dispersed phase of OMMTs and SLFs in matrix. Non-isothermal curing behaviors of IPNs/OMMTs/SLFs composites were investigated by means of the differential scanning calorimeter (DSC). The results of DSC testsshowed that the introduction of OMMTs and SLFs into IPNs accelerated the curing reaction of epoxy systems. In comparisonwith the case of the pristine IPNs, the thermal stability properties, the glass transition temperature, mechanical properties ofIPNs/OMMTs/SLFs composites were markedly enhanced. A desirable toughening-strengthening balance of the compositeshad been obtained at 5 pbw(parts by weight) of OMMTs and 0.5 pbw of SLFs. Significant improvements in performances ofIPNs/OMMTs/SLFs composites obtained through the addition of OMMTs and SLFs in IPNs matrix were associated withtheir good co-reinforcement and co-dispersion effects. The macroscopic properties of the composites were found to bestrongly dependent on their concentrations, components, dispersion, and the resulted morphological structures.

Numerical simulation and experimental validation for investigating the novel hydraulicbarrier-hydrocyclone in industrial beneficiation process

Xinfeng Lv,Lan Xiang,Tiefeng Wang,Shanjun Du 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

In the face of the dwindling reserves of high-quality phosphate rock resources in the world, beneficiationand purification of low-grade phosphate ore is a possible solution to alleviate the growing scarcity forstrategic phosphorus resources. Hydrocyclone is one of the common equipment for solid–solid separationin liquid medium, which is suitable for mineral beneficiation processing. The study investigated theindustrial beneficiation of low-grade phosphate ore by novel hydraulicbarrier-hydrocyclone. The resultsfrom computational fluid dynamics (CFD) simulation revealed that Semi-through hydraulicbarrier (S-Hb)hydrocyclone had the optimal performance, making short-circuit flow reduced to 7.17% and eliminatingfish hook effect, so that the classification efficiency increased by 5% and separation sharpness reached0.9516. The reasons leading to performance intensification were elaborated in accordance with the optimizationand integration of hydrodynamics multiphase flow field by hydraulicbarrier, including the pressure,velocity, turbulent kinetic energy distribution and air core development, as well as streamlineanalysis, etc. The results from practical industrial experiment indicated that the P2O5 grade was increasedto 23.6wt.% from an initial grade of 17.5wt.%, meeting the medium-grade phosphate ore specifications,and the SiO2 content was decreased from 29.0wt.% to 4.2wt.%, meanwhile, the proportional error was0.74% about cutting size compared to simulation results, indicating excellent consistency. The investigationoffered an economically viable route to beneficiate the low-grade phosphate ore, cogently supportingsustainable development of phosphorus resources in chemical engineering.

Optimal Consensus Control for Heterogeneous Nonlinear Multiagent Systems with Partially Unknown Dynamics

Tao Wang,Hao Fu,Jinbin Li,Yaodong Zhang,Xinfeng Zhou,Xin Chen 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.9

This paper focuses on an optimal consensus problem for heterogeneous discrete-time nonlinear multiagent systems (MASs) with partially unknown dynamics. For those systems, it is difficult to obtain the solution of the coupled Hamilton-Jacobi-Bellman (HJB) equations, which is necessary to address the optimal consensus problem. A new hierarchical and distributed optimal control strategy is developed to derive the near solution of the HJB equations. Its control structure consists of the model reference adaptive control (MRAC) layer and distributed control layer. In the MRAC layer, the adaptive feedforward and feedback controller is designed to make the states of followers converge to ones of their corresponding reference models. Then, the optimal consensus problem of heterogeneous MASs is formulated as that of homogeneous MASs. In the distributed control layer, an online distributed value iteration algorithm is proposed to approximate the optimal solution of the HJB equations for reference models. Thereby, the optimal consensus is also achieved for the heterogeneous MASs. The two convergence properties are analyzed to demonstrate the MRAC performance and the optimal consensus, respectively. Simulation results verify the effectiveness of the proposed strategy.

Optimization of the Extraction Process for Flavonoids from Lotus Receptacle and Their Antioxidant Activities

Weicheng Hu,Xinfeng Wang,Pengxia Li,Zuoshan Feng 한국식품영양과학회 2014 한국식품영양과학회 학술대회발표집 Vol.2014 No.10

Influence of Interface Structure on Dielectric Properties of Epoxy/Alumina Nanocomposites

Jinhong Yu,Genglin Wang,Ruimei Huo,Chao Wu,Xinfeng Wu,Pingkai Jiang 한국고분자학회 2012 Macromolecular Research Vol.20 No.8

Alumina (Al2O3) nanoparticles with three different interface structures have been selected as reinforcement fillers for epoxy nanocomposite, that is surface untreated Al2O3 nanoparticles, γ-aminopropyl-triethoxysilane modified Al2O3 nanoparticles (Al2O3-APS), and hyperbranched aromatic polyamide grafted Al2O3 nanoparticles (Al2O3-HBP). The interface structures of the Al2O3 nanoparticles were characterized by X-ray diffraction and atomic force micrographs. Our studies reported the influence of the interface structure of Al2O3 nanoparticles on the morphology and dielectric properties of epoxy nanocomposites. It was found that the incorporation of the Al2O3-APS and Al2O3-HBP nanoparticles not only improved the dispersion of the nanoparticles in the epoxy matrix, but also enhanced the glass transition temperatures (Tgs) and largely influenced the dielectric properties of the epoxy nanocomposites as compared with the nanocomposites filled with the surface untreated Al2O3 nanoparticles. The improvement of Tgs, volume resistivity, dielectric strength, and the reduction of dielectric loss could be attributed to the good dispersion and special interface structure of the Al2O3 nanoparticles in the epoxy matrix.

Polymorphisms in the uncoupling protein 3 gene and their associations with feed efficiency in chickens

Jin, Sihua,Yang, Lei,He, Tingting,Fan, Xinfeng,Wang, Yiqiu,Ge, Kai,Geng, Zhaoyu Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.9

Objective: The uncoupling protein 3 (UCP3) is a member of the mitochondrial anion carrier superfamily and has crucial effects on growth and feed efficiency in many species. Therefore, the objective of the present study was to examine the association of polymorphisms in the UCP3 gene with feed efficiency in meat-type chickens. Methods: Six single nucleotide polymorphisms (SNPs) of the UCP3 gene were chosen to be genotyped using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry in meat-type chicken populations with 724 birds in total. Body weight at 49 (BW49) and 70 days of age (BW70) and feed intake (FI) in the interval were collected, then body weight gain (BWG) and feed conversion ratio (FCR) were calculated individually. Results: One SNP with a low minor allele frequency (<1%) was removed by quality control and data filtering. The results showed that rs13997809 of UCP3 was significantly associated with BWG and FCR (p<0.05), and that rs13997811 had significant effects on BW70 and BWG (p<0.05). Rs13997812 of UCP3 was strongly associated with BW70, FI, and FCR (p<0.05). Furthermore, individuals with AA genotype of rs13997809 had significantly higher BWG and lower FCR (p<0.05) than those with AT genotype. The GG individuals showed strongly higher BW70 and BWG than AA birds in rs13997811 (p<0.05). Birds with the TT genotype of rs13997812 had significantly greater BW70 and lower FCR compared with the CT birds (p<0.05). In addition, the TAC haplotype based on rs13997809, rs13997811, and rs13997812 showed significant effects on BW70, FI, and FCR (p<0.05). Conclusion: Our results therefore demonstrate important roles for UCP3 polymorphisms in growth and feed efficiency that might be used in meat-type chicken breeding programs.