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Lupachev EV, Zakhlevniy AV, Kvashnin SY, Lotkhov VA, Kulov NN. Vapor–Liquid Equilibrium of Binary Components of the BrCF2COOCH3–CF3COOH–BrCF2COOH–CF3COOCH3 Quaternary System. THEORETICAL FOUNDATIONS OF CHEMICAL ENGINEERING 2018. [DOI: 10.1134/s0040579518030119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kvashnin SY, Lupachev EV, Lotkhov VA, Kuritsyn NN, Kulov NN. Chemical Equilibrium and the Kinetics of Transesterification Reactions of Fluoroorganic Esters and Acids. THEORETICAL FOUNDATIONS OF CHEMICAL ENGINEERING 2018. [DOI: 10.1134/s0040579517060100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Li Y, Qi Y, Ritho J, Zhang Y, Zheng X, Zhou J, Sun L. Characterization of flavonoid glycosides from rapeseed bee pollen using a combination of chromatography, spectrometry and nuclear magnetic resonance with a step-wise separation strategy. Nat Prod Res 2015; 30:228-31. [PMID: 25981986 DOI: 10.1080/14786419.2015.1041942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
To identify the structures of flavonoid glycosides in bee pollen collected from rapeseed plants (Brassica napus L.), we utilised an approach that combined liquid chromatography-diode array detector-electrospray ionization-mass spectrometry (LC-DAD-ESI-MS) and nuclear magnetic resonance (NMR) technology with a step-wise separation strategy. We identified four constituents of high purity in rape bee pollen samples: (1) quercetin-3-O-β-D-glucosyl-(2→l)-β-glucoside, (2) kaempferol-3, 4'-di-O-β-D-glucoside, (3) 5, 7, 4'-trihydroxy-3'-methoxyflavone-3-O-β-D-sophoroside and (4) kaempferol-3-O-β-D-glucosyl-(2→l)-β-D-glucoside. This study will also provide useful reference standards for qualification and quantification of four flavonoid glycosides in natural products.
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Affiliation(s)
- Yi Li
- a Institute of Apicultural Research, Chinese Academy of Agricultural Sciences , Beijing 100093 , P.R. China.,b Bee Product Quality Supervision and Testing Center, Ministry of Agriculture , Beijing 100093 , P.R. China.,c Laboratory of Risk Assessment for Quality and Safety of Bee Products, Ministry of Agriculture , Beijing 100093 , P.R. China
| | - Yitao Qi
- d Texas Heart Institute, St Luke's Episcopal Hospital , Houston , TX 77030 , USA
| | - Joan Ritho
- e Department of Cardiology , The University of Texas MD Anderson Cancer Center , Houston , TX 77030 , USA
| | - Yongxin Zhang
- f Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences , Beijing 10070 , P.R. China
| | - Xiaowei Zheng
- g Henan Enginerring Laboratory of Antibody Medicine, Medical School of Henan University , Kaifeng 475001 , P.R. China
| | - Jinhui Zhou
- a Institute of Apicultural Research, Chinese Academy of Agricultural Sciences , Beijing 100093 , P.R. China.,b Bee Product Quality Supervision and Testing Center, Ministry of Agriculture , Beijing 100093 , P.R. China.,c Laboratory of Risk Assessment for Quality and Safety of Bee Products, Ministry of Agriculture , Beijing 100093 , P.R. China
| | - Liping Sun
- a Institute of Apicultural Research, Chinese Academy of Agricultural Sciences , Beijing 100093 , P.R. China.,h Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture , Beijing 100093 , P.R. China
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Cecchi T. Theoretical Models of Ion Pair Chromatography: A Close Up of Recent Literature Production. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2014.941267] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Teresa Cecchi
- a Accademia delle Scienze dell'Istituto di Bologna , Bologna , Italy
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Qin X, Xie W, Tian S, Ali MA, Shirke A, Gross RA. Influence of Nε-Protecting Groups on the Protease-Catalyzed Oligomerization of l-Lysine Methyl Ester. ACS Catal 2014. [DOI: 10.1021/cs500268d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Xu Qin
- Rensselaer Polytechnic Institute (RPI), Department of Chemistry and Biology,
Center for Biotechnology and Interdisciplinary Studies, 4005B BioTechnology Bldg., 110 Eighth
Street, Troy, New York 12180, United States
| | - Wenchun Xie
- Rensselaer Polytechnic Institute (RPI), Department of Chemistry and Biology,
Center for Biotechnology and Interdisciplinary Studies, 4005B BioTechnology Bldg., 110 Eighth
Street, Troy, New York 12180, United States
| | - Sai Tian
- Rensselaer Polytechnic Institute (RPI), Department of Chemistry and Biology,
Center for Biotechnology and Interdisciplinary Studies, 4005B BioTechnology Bldg., 110 Eighth
Street, Troy, New York 12180, United States
| | - Mohamed Abo Ali
- Rensselaer Polytechnic Institute (RPI), Department of Chemistry and Biology,
Center for Biotechnology and Interdisciplinary Studies, 4005B BioTechnology Bldg., 110 Eighth
Street, Troy, New York 12180, United States
| | - Abhijeet Shirke
- Rensselaer Polytechnic Institute (RPI), Department of Chemistry and Biology,
Center for Biotechnology and Interdisciplinary Studies, 4005B BioTechnology Bldg., 110 Eighth
Street, Troy, New York 12180, United States
| | - Richard A. Gross
- Rensselaer Polytechnic Institute (RPI), Department of Chemistry and Biology,
Center for Biotechnology and Interdisciplinary Studies, 4005B BioTechnology Bldg., 110 Eighth
Street, Troy, New York 12180, United States
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Comparison of retention behavior of oligolysine and oligoarginine in ion-pairing chromatography using heptafluorobutyric acid. Anal Bioanal Chem 2013; 405:9739-46. [DOI: 10.1007/s00216-013-7397-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/21/2013] [Accepted: 09/23/2013] [Indexed: 12/01/2022]
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Reversed phase ion-pairing chromatography of an oligolysine mixture in different mobile phases: effort of searching critical chromatography conditions. J Chromatogr A 2013; 1304:127-32. [PMID: 23876768 DOI: 10.1016/j.chroma.2013.06.078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/28/2013] [Accepted: 06/28/2013] [Indexed: 11/23/2022]
Abstract
Our earlier study [J. Chromatogr. A 1218 (2011) 7765] on separation of an oligolysine mixture consisting of chains with 2-8 lysine residues (number of lysine residues, dp=2-8) by ion-pairing reversed-phase chromatography using heptafluorobutyric acid (HFBA) as an ion pairing reagent at fixed mobile phase acetonitrile (ACN) content was extended to isocratic elution conditions with different ACN percentages. The present work explored how manipulating the mobile phase HFBA concentration ([HFBA]) and %-ACN content influences separations of the oligolysine mixture. The closed pairing model was used to analyze variation of the retention factor as a function of [HFBA]. The partition coefficient of the paired peptide decreased with increasing %-ACN. Pairing of HFBA to oligolysine was cooperative, and the effect increased when %-ACN in the mobile phase was lowered. A plot of the partition coefficient as a function of %-ACN for oligolysines varying in dp converged at one ACN content, indicating a critical condition in which components of different dp co-elute.
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Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities. J Pharm Biomed Anal 2013; 77:9-15. [DOI: 10.1016/j.jpba.2013.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/19/2012] [Accepted: 01/01/2013] [Indexed: 11/20/2022]
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