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A Mechanistic Understanding of Monoclonal Antibody Interfacial Protection by Hydrolytically Degraded Polysorbate 20 and 80 under IV Bag Conditions. Pharm Res 2022; 39:563-575. [PMID: 35277841 DOI: 10.1007/s11095-022-03217-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/24/2022] [Indexed: 10/18/2022]
Abstract
PURPOSE Polysorbates (PS) contain polyoxyethylene (POE) sorbitan/isosorbide fatty acid esters that can partially hydrolyze over time in liquid drug products to generate degradants and a remaining intact PS fraction with a modified ester distribution. The degradants are composed of free fatty acids (FFAs) --primarily lauric acid for PS20 and oleic acid for PS80-- and POE head groups. We previously demonstrated that under IV bag agitation conditions, mAb1 (a surface-active IgG4) aggregation increased with increasing amounts of degradants for PS20 but not for PS80. The purpose of this work is to understand the mechanism behind this observation. METHODS The surface tension of the remaining intact PS fraction without degradants was modeled and compared with that of enzymatically degraded PS solutions. Next, mAb1 aggregation in saline was measured in the presence of laurate and oleate salts during static storage. Lastly, colloidal and conformational stability of mAb1 in the presence of these salts was investigated through differential scanning fluorimetry and dynamic light scattering under IV bag solution conditions. RESULTS The surface tension was primarily influenced by FFAs rather than the modified ester distribution of the remaining intact PS. MAb1 bulk aggregation increased in the presence of laurate but not oleate salts. Both salt types increased the melting temperature of mAb1 indicating FFA-mAb1 interactions. However, only laurate salt increased mAb1 self-association potentially explaining the higher aggregation propensity in its presence. CONCLUSION Our results help explain the observed differences between hydrolytically degraded PS20 and PS80 in affecting mAb1 aggregation under IV bag agitation conditions.
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Ludwig M, Geisler R, Prévost S, von Klitzing R. Shape and Structure Formation of Mixed Nonionic-Anionic Surfactant Micelles. Molecules 2021; 26:molecules26144136. [PMID: 34299413 PMCID: PMC8307929 DOI: 10.3390/molecules26144136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/29/2021] [Accepted: 07/03/2021] [Indexed: 11/16/2022] Open
Abstract
Aqueous solutions of a nonionic surfactant (either Tween20 or BrijL23) and an anionic surfactant (sodium dodecyl sulfate, SDS) are investigated, using small-angle neutron scattering (SANS). SANS spectra are analysed by using a core-shell model to describe the form factor of self-assembled surfactant micelles; the intermicellar interactions are modelled by using a hard-sphere Percus–Yevick (HS-PY) or a rescaled mean spherical approximation (RMSA) structure factor. Choosing these specific nonionic surfactants allows for comparison of the effect of branched (Tween20) and linear (BrijL23) surfactant headgroups, both constituted of poly-ethylene oxide (PEO) groups. The nonionic–anionic surfactant mixtures are studied at various concentrations up to highly concentrated samples (ϕ ≲ 0.45) and various mixing ratios, from pure nonionic to pure anionic surfactant solutions. The scattering data reveal the formation of mixed micelles already at concentrations below the critical micelle concentration of SDS. At higher volume fractions, excluded volume effects dominate the intermicellar structuring, even for charged micelles. In consequence, at high volume fractions, the intermicellar structuring is the same for charged and uncharged micelles. At all mixing ratios, almost spherical mixed micelles form. This offers the opportunity to create a system of colloidal particles with a variable surface charge. This excludes only roughly equimolar mixing ratios (X≈ 0.4–0.6) at which the micelles significantly increase in size and ellipticity due to specific sulfate–EO interactions.
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Affiliation(s)
- Michael Ludwig
- Soft Matter at Interfaces, Institute for Condensed Matter Physics, Technical University of Darmstadt, D-64289 Darmstadt, Germany; (M.L.); (R.G.)
| | - Ramsia Geisler
- Soft Matter at Interfaces, Institute for Condensed Matter Physics, Technical University of Darmstadt, D-64289 Darmstadt, Germany; (M.L.); (R.G.)
| | - Sylvain Prévost
- Large Scale Structures Group, DS/LSS, Institut Laue-Langevin, CEDEX 9, 38042 Grenoble, France;
| | - Regine von Klitzing
- Soft Matter at Interfaces, Institute for Condensed Matter Physics, Technical University of Darmstadt, D-64289 Darmstadt, Germany; (M.L.); (R.G.)
- Correspondence:
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Doshi N, Giddings J, Luis L, Wu A, Ritchie K, Liu W, Chan W, Taing R, Chu J, Sreedhara A, Kannan A, Kei P, Shieh I, Graf T, Hu M. A Comprehensive Assessment of All-Oleate Polysorbate 80: Free Fatty Acid Particle Formation, Interfacial Protection and Oxidative Degradation. Pharm Res 2021; 38:531-548. [PMID: 33713012 DOI: 10.1007/s11095-021-03021-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/22/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Enzymatic polysorbate (PS) degradation and resulting free fatty acid (FFA) particles are detrimental to biopharmaceutical drug product (DP) stability. Different types and grades of polysorbate have varying propensity to form FFA particles. This work evaluates the homogenous all-oleate (AO) PS80 alongside heterogeneous PS20 and PS80 grades in terms its propensity to form FFA particles and other important attributes like interfacial protection and oxidation susceptibility. METHODS FFA particle formation rates were compared by degrading PS using non-immobilized hydrolases and fast degrading DP formulations. Interfacial protection of monoclonal antibodies (mAbs) was assessed by agitation studies in saline using non-degraded and degraded PS. Several antioxidants were assessed for their ability to mitigate AO PS80 oxidation and subsequent mAb oxidation by a 40°C placebo stability study and a 2, 2'-Azobis (2-amidinopropane) dihydrochloride stress model, respectively. RESULTS Visible and subvisible particles were significantly delayed in AO PS80 formulations compared with heterogeneous PS20 and PS80 formulations. Non-degraded AO PS80 was less protective of mAbs against the air-water interface compared with heterogeneous PS20. Interfacial protection by AO PS80 improved upon degradation owing to high surface activity of FFAs. Diethylenetriaminepentaacetic acid (DTPA) completely mitigated AO PS80 oxidation unlike L-methionine and N-Acetyl-DL-Tryptophan. However, DTPA did not mitigate radical mediated mAb oxidation. CONCLUSION AO PS80 is a promising alternative to reduce FFA particle formation compared with other PS types and grades. However, limitations observed here---such as lower protection against interfacial stresses and higher propensity for oxidation---need to be considered in assessing the risk/benefit ratio in using AO PS80.
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Affiliation(s)
- Nidhi Doshi
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA.
| | - Jamie Giddings
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Lin Luis
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Arthur Wu
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Kyle Ritchie
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Wenqiang Liu
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Wayman Chan
- Analytical Operations, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Rosalynn Taing
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Jeff Chu
- Analytical Operations, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Alavattam Sreedhara
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Aadithya Kannan
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Pervina Kei
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Ian Shieh
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
| | - Tobias Graf
- Pharma Technical Development Analytics, Roche Diagnostics GmbH, Nonnenwald 2, 82377, Penzberg, Germany
| | - Mark Hu
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California, 94080, USA
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Doshi N, Rutherford K, Najjar A. Dissolution of Polysorbate 20 Degradation Related Free Fatty Acid Particles in Intravenous Bag Solutions. J Pharm Sci 2020; 110:687-692. [PMID: 33039438 DOI: 10.1016/j.xphs.2020.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/03/2020] [Accepted: 10/05/2020] [Indexed: 11/15/2022]
Abstract
Degradation of Polysorbate 20 (PS20), a commonly used surfactant in drug product (DP) formulations, is a phenomenon of increasing concern to the biopharmaceutical industry. One of the most prevalent modes of PS20 degradation is enzymatic hydrolysis resulting from co-purified hydrolases that make their way into biologic DP formulations at trace levels. Enzymatic PS20 degradation results in generation of free fatty acids (FFAs) that have limited solubility in aqueous formulations and can form visible and/or sub-visible particles which is undesirable for parenteral DP stability and administration. Many therapeutic monoclonal antibodies are administered intravenously after first diluting the DP into an infusion solution (e.g., 0.9% normal saline, 0.45% half normal saline or 5% dextrose). The purpose of this work is to understand if FFA particles in the DP dissolve in intravenous solutions prior to administration. Our assessment indicates that visible and/or sub-visible particles that contain high levels of lauric, myristic and palmitic acids dissolve immediately upon dilution (at or exceeding two fold) regardless of the intravenous bag or solution type. Therefore, the risk is low of visible and/or sub-visible particles, comprised of FFAs in biopharmaceutical DPs, being intravenously administered to a patient.
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Affiliation(s)
- Nidhi Doshi
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Karen Rutherford
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Asil Najjar
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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Doshi N, Martin J, Tomlinson A. Improving Prediction of Free Fatty Acid Particle Formation in Biopharmaceutical Drug Products: Incorporating Ester Distribution during Polysorbate 20 Degradation. Mol Pharm 2020; 17:4354-4363. [DOI: 10.1021/acs.molpharmaceut.0c00794] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Nidhi Doshi
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Joelle Martin
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
- Therapeutic Discovery, Amgen Research, Amgen Inc., 1120 Veterans Blvd, South San Francisco, California 94080, United States
| | - Anthony Tomlinson
- Pharmaceutical Development, Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
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Penfield KW, Rumbelow S. Challenges in polysorbate characterization by mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34 Suppl 2:e8709. [PMID: 31943438 DOI: 10.1002/rcm.8709] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/05/2019] [Accepted: 12/17/2019] [Indexed: 06/10/2023]
Abstract
Polysorbates are used in a variety of applications over a wide range of markets. Simple in concept, these products are complex in actual composition. Mass spectrometry and related techniques have been effectively used to characterize these products, from the major components to the minor residual production byproducts and degradation species. In this paper we review the use of MALDI-MS, LC/MS, GC/MS, and SFC/MS in the analysis of these materials. The wealth of information provided by MALDI is presented, using Polysorbate 60 as an example. Limitations are described, with the impact of matrix selection and cationization agent demonstrated. Furthermore, unique challenges of MALDI analysis of Polysorbate 80 are shown. Polysorbates have been extensively analyzed, especially by the biopharmaceutical industry, to better understand the impact of various grades of purity and manufacture on the stability of formulations. Using Polysorbate 80 as an example, we illustrate some of the more advanced techniques used to more fully characterize these complex molecules using high-resolution LC/MS and LC/MS/MS. Finally, the use of other techniques (such as GC/MS and SFC/MS) is briefly reviewed.
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Clausen PA, Kofoed-Sørensen V, Nørgaard AW, Sahlgren NM, Jensen KA. Thermogravimetry and Mass Spectrometry of Extractable Organics from Manufactured Nanomaterials for Identification of Potential Coating Components. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3657. [PMID: 31698885 PMCID: PMC6888238 DOI: 10.3390/ma12223657] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/29/2019] [Accepted: 11/01/2019] [Indexed: 02/07/2023]
Abstract
Manufactured nanomaterials (MNMs) often have a surface-chemical modification in order to tailor their physicochemical properties, including also powder properties and miscibility. Surface-chemical modifications may influence the toxicological properties of the MNM, but the specific chemistry and extent are rarely described in detail in suppliers' technical data sheets. Chemical and quantitative information on any surface-chemical treatment, coating and functionalization are required for chemicals registration in Europe. Currently there is no globally accepted and documented approach to generate such data. Consequently, there is a continued research need to establish a structured approach to identify and quantify surface-chemical modifications. Here we present a tiered approach starting with screening for mass-loss during heating in a furnace or thermogravimetric analysis (TGA) followed by solvent extraction, and analysis by several mass spectrometry (MS) techniques depending on the target analytes. Thermal treatment was assumed to be able to quantify the amount of organic coating and MS was used to identify the extractable organic coatings after pressurized liquid extraction (PLE) using methanol at 200 °C. Volatile organic compounds in extracts were identified with gas chromatography and MS (GC-MS), non-volatile organic compounds with liquid chromatography MS (LC-MS), and polymeric compounds with matrix-assisted laser desorption ionization time-of-flight MS (MALDI-TOF-MS). The approach was demonstrated by analysis of 24 MNM, comprising titanium dioxide, synthetic amorphous silica, graphite, zinc oxide, silver, calcium carbonate, iron oxide, nickel-zinc-iron oxide, and organoclay. In extracts of 14 MNMs a range of organic compounds were identified and the main groups were silanes/siloxanes, fatty acids, fatty acid esters, quaternary ammonium compounds and polymeric compounds. In the remaining 10 MNMs no organic compounds were detected by MS, despite the fact an organic coating was indicated by TGA.
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Affiliation(s)
- Per Axel Clausen
- National Research Centre for the Working Environment, DK-2100 Copenhagen, Denmark; (V.K.-S.); (A.W.N.); (N.M.S.)
| | - Vivi Kofoed-Sørensen
- National Research Centre for the Working Environment, DK-2100 Copenhagen, Denmark; (V.K.-S.); (A.W.N.); (N.M.S.)
| | - Asger W. Nørgaard
- National Research Centre for the Working Environment, DK-2100 Copenhagen, Denmark; (V.K.-S.); (A.W.N.); (N.M.S.)
- Novo Nordisk, DK-2760 Måløv, Denmark
| | - Nicklas Mønster Sahlgren
- National Research Centre for the Working Environment, DK-2100 Copenhagen, Denmark; (V.K.-S.); (A.W.N.); (N.M.S.)
| | - Keld Alstrup Jensen
- National Research Centre for the Working Environment, DK-2100 Copenhagen, Denmark; (V.K.-S.); (A.W.N.); (N.M.S.)
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Degradation Mechanisms of Polysorbate 20 Differentiated by 18O-labeling and Mass Spectrometry. Pharm Res 2016; 34:84-100. [DOI: 10.1007/s11095-016-2041-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 09/16/2016] [Indexed: 01/18/2023]
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9
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Dixit N, Salamat-Miller N, Salinas PA, Taylor KD, Basu SK. Residual Host Cell Protein Promotes Polysorbate 20 Degradation in a Sulfatase Drug Product Leading to Free Fatty Acid Particles. J Pharm Sci 2016; 105:1657-1666. [DOI: 10.1016/j.xphs.2016.02.029] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 02/19/2016] [Accepted: 02/24/2016] [Indexed: 11/16/2022]
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10
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Zhou X, Wan QH. Separation and identification of oligomeric ethyl silicates by liquid chromatography with electrospray ionization mass spectrometry. J Sep Sci 2015; 38:1484-90. [PMID: 25678216 DOI: 10.1002/jssc.201401184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 01/31/2015] [Accepted: 02/03/2015] [Indexed: 11/07/2022]
Abstract
Reversed-phase liquid chromatography coupled with electrospray ionization mass spectrometry was used to study the molecular structures of components and molar mass distributions in ethyl silicate-40, a versatile liquid precursor for silicon-based materials. Identity testing by standard spectroscopic techniques showed that a commercial sample of ethyl silicate-40 was composed of linear/branched ethoxysiloxane oligomers with the silicon atoms ranging from 2 to 12 together with minor monocyclic species. Analysis of the sample by liquid chromatography coupled with evaporative light scattering detection resulted in an elution profile consisting of a series of peak clusters. Peak identification showed that the linear/branched homologous series of oligomers were eluted in the order of increasing number of silicon atoms in the molecules and the time duration (width) of the resulting peak clusters increased in the same fashion corresponding to increasing number of geometric isomers. In addition, small amounts of monocyclic oligomers present in the sample were found to be less retained than each linear/branched counterpart. Finally, the molar mass distribution parameters for ethyl silicate-40 determined by the developed method were in good agreement with the literature values. Overall, this work demonstrates that reversed-phase liquid chromatography coupled with electrospray ionization mass spectrometry is an indispensable tool for the comprehensive characterization of complex mixtures of this type.
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Affiliation(s)
- Xiuli Zhou
- School of Pharmaceutical Science and Technology, Tianjin University, China
| | - Qian-Hong Wan
- School of Pharmaceutical Science and Technology, Tianjin University, China
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11
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Abrar S, Trathnigg B. Characterization of Commercial Polysorbates Using Different Chromatographic Techniques. TENSIDE SURFACT DET 2013. [DOI: 10.3139/113.110032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Polysorbates – which are commercially available under the name Tween – are complex mixtures of different functionalities. Molar mass distribution and chemical composition of various Tween samples (20, 40, 60 and 65) were determined using size exclusion chromatography (SEC) with dual detection. A separation of different functionalities was achieved using liquid chromatography under critical conditions (LCCC) on typical reversed phase columns with methanol – water and acetone – water as mobile phase. The size of the hydrophilic part was determined after microwave-assisted methanolysis, which allowed also the identification of the fatty acids bound to the hydrophilic core.
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Wulf V, Wienand N, Wirtz M, Kling HW, Gäb S, Schmitz OJ. Analysis of special surfactants by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. J Chromatogr A 2010; 1217:749-54. [DOI: 10.1016/j.chroma.2009.11.093] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 10/12/2009] [Accepted: 11/30/2009] [Indexed: 11/26/2022]
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Watanabe T, Okumura K, Nozaki K, Kawasaki H, Arakawa R. Selective photocatalytic degradation of poly(ethylene glycol) additives using TiO2 surface-assisted laser desorption/ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:3886-3890. [PMID: 19902422 DOI: 10.1002/rcm.4305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Mohammad A, Bhawani SA. On Plate Identification of Coexisting Polyoxyethylene (20) Stearyl Ether, Cetyl Pyridinium Chloride, Tetradecyl Trimethyl Ammonium Bromide and Polyoxyethylene (9.5) Octyl Phenyl Ether Surfactants with Preliminary Separation by Planar Chromatography. J SURFACTANTS DETERG 2009. [DOI: 10.1007/s11743-009-1160-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Templating multiple length scales by combining phase separation, self-assembly and photopatterning in porous films. J Colloid Interface Sci 2008; 328:374-84. [DOI: 10.1016/j.jcis.2008.09.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 09/09/2008] [Accepted: 09/10/2008] [Indexed: 11/24/2022]
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16
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Analysis of neutral surfactants by non-aqueous medium capillary electrophoresis hyphenated to mass spectrometry (ion trap). J Chromatogr A 2008; 1198-1199:226-31. [DOI: 10.1016/j.chroma.2008.05.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 05/06/2008] [Accepted: 05/15/2008] [Indexed: 11/20/2022]
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17
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Determination of fatty alcohol ethoxylates by derivatisation with maleic anhydride followed by liquid chromatography with UV–vis detection. J Chromatogr A 2008; 1180:32-41. [DOI: 10.1016/j.chroma.2007.11.105] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Revised: 11/28/2007] [Accepted: 11/30/2007] [Indexed: 11/17/2022]
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18
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Huhn C, Pütz M, Holthausen I, Pyell U. Separation of very hydrophobic analytes by micellar electrokinetic chromatography. I. Optimization of the composition of the sample solution for the determination of the aromatic ingredients of sassafras and other essential oils of forensic interest. Electrophoresis 2008; 29:526-37. [DOI: 10.1002/elps.200700156] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Watanabe T, Kawasaki H, Kimoto T, Arakawa R. Characterization of polyether mixtures using thin-layer chromatography and matrix-assisted laser desorption/ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:787-91. [PMID: 17279480 DOI: 10.1002/rcm.2896] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Thin-layer chromatography (TLC) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) were combined to achieve characterization of polyether mixtures. Three polyethers, polyethylene glycol (PEG), polypropylene glycol (PPG) and polytetramethylene glycol (PTMG), or mixtures of these compounds, were studied. One shortcoming of mixture analysis of synthetic polymers using MALDI-MS is that individual polymers in the mixture may display different detection sensitivities. For example, the MALDI mass spectrum of an equimolar mixture of PEG, PPG and PTMG displayed a high intensity of PPG ions, while no PTMG ions were detectable; however, PTMG ions were detected after the mixture had been separated by TLC. This combined TLC and MALDI-MS analysis of a PPG polymer bearing reactive epoxy groups showed that the polymer contained byproducts with different end-groups. These byproducts were identified as chloro-substituted polymers formed during polymer synthesis. Our study shows TLC to be a rapid and low-cost separation technique, and that it can be combined with MALDI-MS to achieve effective analysis of synthetic polymers.
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Affiliation(s)
- Takehiro Watanabe
- Department of Applied Chemistry, Kansai University, Suita, Osaka 564-8680, Japan
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20
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Bernabé-Zafón V, Simó-Alfonso EF, Ramis-Ramos G. On the determination of underivatised fatty alcohol ethoxylates by electrospray ionisation–mass spectrometry. J Chromatogr A 2006; 1118:188-98. [PMID: 16620850 DOI: 10.1016/j.chroma.2006.03.093] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 03/15/2006] [Accepted: 03/27/2006] [Indexed: 10/24/2022]
Abstract
The oligomers of fatty alcohol ethoxylates (FAEs) exhibit large sensitivity differences in mass spectrometry with electrospray ionisation (ESI-MS) and atmospheric pressure chemical ionization (APCI). Standards of the oligomers from m=1 to 7 ethylene oxide units (EOs) and linear alkyl chains from n=10 to 18 carbon atoms were infused to examine the relative sensitivities or response factors in several media. The response factors of the [M+H]+ and [M+Na]+ peaks in 9:1 acetonitrile/water and methanol/water media containing acid buffers increased following irregular patterns when n and m increased. In methanol/water the response factors depended on the parity of m, being larger than the average trend for the oligomers with an even value of m with respect to those having an odd value. This was attributed to the presence of an uncompensated C-O-C or C-O-H dipole in the former oligomers. The advantages of using ESI over APCI and of measuring the [M+H]+ peaks in an acid methanol/water medium containing 0.1 M HCl are discussed. The advantages and limitations of using models of the response factors to evaluate oligomer concentrations with a reduced set of selected standards are examined. The determination of underivatised FAEs using acid media was made compatible with previous HPLC separation by implementing either a triconcentric nebulizer fed with an acid liquid sheath, or a capillary T-union inserted between the column outlet and the biconcentric nebulizer, and fed with an acid stream provided by a syringe pump.
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Affiliation(s)
- Virginia Bernabé-Zafón
- Departament de Química Analítica, Universitat de València, Dr. Moliner 50, 46100 Burjassot, Spain
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Raith K, Schmelzer CEH, Neubert RHH. Towards a molecular characterization of pharmaceutical excipients: mass spectrometric studies of ethoxylated surfactants. Int J Pharm 2006; 319:1-12. [PMID: 16730931 DOI: 10.1016/j.ijpharm.2006.03.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Revised: 09/21/2005] [Accepted: 03/24/2006] [Indexed: 11/25/2022]
Abstract
The in-depth characterization of excipients is a prerequisite for their safe application in pharmaceutical products. In case of surfactants, this task can be a challenge, since many industrial products are mixtures of variable composition. In this work, mass spectrometric methods are applied to characterize some ethoxylated surfactants that are widely used by the pharmaceutical industry. Among them are ethoxylated fatty alcohols with ether structure (e.g., Brij, ethoxylated fatty acids with ester structure (e.g., Myrj, ethoxylated sorbitane fatty acid esters (e.g., Tween, ethoxylated glycerides (e.g., Tagat, and Triton X-100. MALDI-TOF mass spectrometry is best suitable to obtain molecular mass distributions of polymeric products, namely those with higher molecular mass. Electrospray and nanoelectrospray molecular mass shows a greater tendency for multiple charges. However, it is best suitable for small MM products, and multiple charges have been de-convoluted successfully using the MaxEnt 3 algorithm. Tandem mass spectrometry helps to identify the chemical composition, e.g. for identification of acyl chains. The work is intended to serve as a reference for mass spectrometric characterization of surfactants in the course of R&D, validation or change control.
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Affiliation(s)
- Klaus Raith
- Martin Luther University Halle-Wittenberg, Department of Pharmacy, Institute of Pharmaceutics and Biopharmaceutics, W-Langenbeck-Str, D-06120 Halle S, Germany.
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Vu Dang H, Gray AI, Watson D, Bates CD, Scholes P, Eccleston GM. Composition analysis of two batches of polysorbate 60 using MS and NMR techniques. J Pharm Biomed Anal 2006; 40:1155-65. [PMID: 16280224 DOI: 10.1016/j.jpba.2005.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 09/30/2005] [Accepted: 10/04/2005] [Indexed: 11/28/2022]
Abstract
Batch variation in Tween 60 has shown to influence the rheological properties of semisolid emulsions. MS (LC-MS, GC-MS, MS(n)) and NMR ((13)C, (1)H, (1)H COSY and HMBC) techniques were used to analyze and compare the composition of two batches of Tween 60 with particular emphasis on the number of POE groups and their distribution within the molecule. Acid and saponification values were also determined. The batches contained different proportions of components (sorbitan polyethoxylates, sorbitan monoester-diester-polyethoxylates and isosorbide monoester-diester-polyethoxylates). The number of POE groups were averaged over the four sites in sorbitan and the two sites in isosorbide molecules. The batches differed from each other in terms of (i) the POE sorbitan stearate/POE sorbitan palmitate ratios (batch 1, 3:2 and batch 2, 4:5), (ii) the ratio of sorbitans to isosorbides (batch 1, 2:3; batch 2, 7:13); and (iii) the acid values (batch 1, 3.1; batch 2, 0). It is concluded that liquid chromatography combined with electrospray mass spectrometry and ion trap separation is a useful tool for establishing the compositional profile of different batches of Tweens. (1)H NMR could provide a simple and rapid pharmacopoeial test for the ratio of sorbitan to isosorbide in Tweens.
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Affiliation(s)
- Hoang Vu Dang
- Department of Pharmaceutical Sciences, Strathclyde Institution of Biomedical Sciences, University of Strathclyde, Glasgow, UK
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OHMOTO M, OKUNO S, ARAKAWA R. Characterization of nonylphenolpolyethoxylates by matrix-assisted laser desorption/ionization mass spectrometry and post-source decay. BUNSEKI KAGAKU 2004. [DOI: 10.2116/bunsekikagaku.53.555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | - Shoji OKUNO
- Japan Science and Technology Agency, Innovation Plaza Osaka, Wada Project Laboratory
| | - Ryuichi ARAKAWA
- Department of Applied Chemistry, Kansai University
- Japan Science and Technology Agency, Innovation Plaza Osaka, Wada Project Laboratory
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Frańska M, Zgoła A, Rychłowska J, Szymański A, Łukaszewski Z, Frański R. Mass spectrometric behaviour of carboxylated polyethylene glycols and carboxylated octylphenol ethoxylates. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2003; 9:165-173. [PMID: 12939494 DOI: 10.1255/ejms.540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mass spectrometric behaviour of mono- and di-carboxylated polyethylene glycols (PEGCs and CPEGCs) and carboxylated octylphenol ethoxylates (OPECs) are discussed. The tendency for ionisation (deprotonation, protonation and cationisation by alkali metal cations) of carboxylated PEGs was compared with that of non-carboxylated correspondents by using both secondary ion mass spectrometry (SIMS) and electrospray ionisation (ESI). The fragmentation of the PEGCs and CPEGCs is discussed and also compared with their neutral correspondents, PEGs. The B/E mass spectra were recorded, using secondary ion mass spectrometry as a method for generation, for deprotonated and protonated molecules and molecules cationised by alkali metal cations. The fragmentation behaviour of PEGs is found to be different from that of CPEGCs, The presence of carboxylic groups may be confirmed not only by the determination of molecular weights of the ethoxylates studied, but also on the basis of the fragment ions formed. The metastable decomposition of the [OPEC-H](-) ions proceed through the cleavage of the bond between the octylphenol moiety and the ethoxylene chain leading to the octylphenoxy anions. It permits determination of the mass of the hydrophobic moiety of the studied carboxylated alkylphenol ethoxylate. ESI mass spectra recorded in the negative ion mode were found to be more suitable for the determination of the average molecular weight of carboxylated ethoxylates than SI mass spectra.
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Affiliation(s)
- Magdalena Frańska
- Poznań University of Technology, Institute of Chemistry, Piotrowo 3, 60-965 Poznań, Poland
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Chen R, Yu X, Li L. Characterization of poly(ethylene glycol) esters using low energy collision-induced dissociation in electrospray ionization mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2002; 13:888-897. [PMID: 12148812 DOI: 10.1016/s1044-0305(02)00396-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A method of characterizing polyglycol esters, an important class of industrial polymer, has been developed using electrospray ionization ion trap mass spectrometry (ESI ITMS). The fragmentation behavior of polyglycol esters is found to be different from that of polyglycols whose functional end groups are linked to the polymer chain via ether bonds (i.e., polyglycol ethers). The fragmentation pattern of an oligomer ion generated by low-energy collision-induced dissociation is strongly dependent on the type of cation used for ionization. It is shown that structural information on the polymer chain and end groups is best obtained by examining the fragment ion spectra of oligomers ionized by ammonium, alkali, and transition metal ions. The application of this method is demonstrated in the analysis of two surfactants based on fatty acid methyl ester ethoxylates.
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Affiliation(s)
- Rui Chen
- Department of Chemistry, University of Alberta, Edmonton, Canada
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Benomar SH, Clench MR, Allen DW. The analysis of alkylphenol ethoxysulphonate surfactants by high-performance liquid chromatography, liquid chromatography–electrospray ionisation–mass spectrometry and matrix-assisted laser desorption ionisation–mass spectrometry. Anal Chim Acta 2001. [DOI: 10.1016/s0003-2670(01)01280-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Chen R, Li L. Lithium and transition metal ions enable low energy collision-induced dissociation of polyglycols in electrospray ionization mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2001; 12:832-839. [PMID: 11444606 DOI: 10.1016/s1044-0305(01)00261-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Electrospray ionization tandem mass spectrometry has the potential to be widely used as a tool for polymer structural characterization. However, the backbones or molecular chains of many industrial polymers including functional polyglycols are often difficult to dissociate in tandem mass spectrometers using low energy collision-induced dissociation (CID). We present a method that uses Li+ and transition metal ions such as Ag+ as the cationization reagents for electrospray ionization in an ion trap mass spectrometer. It is shown that lithium and transition metal polyglycol adduct ions can be readily fragmented with low energy CID. Comparative results from different cationization reagents in their abilities of producing both MS spectra and CID spectra are shown. This method opens the possibility of using conventional and readily available low energy CID tandem MS to study polyglycol structures.
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Affiliation(s)
- R Chen
- Department of Chemistry, University of Alberta, Edmonton, Canada
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Characterization of biodegradation intermediates of non-ionic surfactants by matrix-assisted laser desorption/ionization–mass spectrometry 1. Bacterial biodegradation of octylphenol polyethoxylate under aerobic conditions. Polym Degrad Stab 2001. [DOI: 10.1016/s0141-3910(01)00102-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Chen R, Tseng AM, Uhing M, Li L. Application of an integrated matrix-assisted laser desorption/ionization time-of-flight, electrospray ionization mass spectrometry and tandem mass spectrometry approach to characterizing complex polyol mixtures. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2001; 12:55-60. [PMID: 11142361 DOI: 10.1016/s1044-0305(00)00200-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Polyols are being used in a wide range of industrial applications including surfactants and precursors for grafted polymers. The characterization of polyols is of significance in correlating compositions and structures with their properties. We illustrate two real world examples where traditional analytical methods including GPC and NMR failed to reveal compositional differences, but the combination of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), electrospray ionization mass spectrometry (ESI MS), and MS/MS can produce compositional information required for problem solving. The first example involves failure analysis of four ethylene oxide and propylene oxide (EO/PO) copolymer products. The results from the mass spectrometry analysis unequivocally demonstrate that one of the samples has a small variation in copolymer composition, leading to its abnormal activity. The second example is in the area of deformulation of complex polyol mixtures. Two samples displaying similar properties and activities were found to be two different polyol blends. One of the samples is a more cost-effective product. These examples demonstrate that MALDI, ESI MS, and MS/MS should be seriously considered as an integrated component of an overall polyol characterization program in product failure analysis and deformulation.
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Affiliation(s)
- R Chen
- Department of Chemistry, University of Alberta, Edmonton, Canada
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Affiliation(s)
- J Sherma
- Department of Chemistry, Lafayette College, Easton, Pennsylvania 18042, USA
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Portet FI, Treiner C, Desbène PL. Simultaneous quantitative trace analysis of anionic and nonionic surfactant mixtures by reversed-phase liquid chromatography. J Chromatogr A 2000; 878:99-113. [PMID: 10843549 DOI: 10.1016/s0021-9673(00)00225-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of this work was to simultaneously analyse mixtures of a polydisperse polyethylene oxide (PEO) nonionic surfactant and an anionic surfactant (sodium dodecylsulphate, SDS) in water containing sodium chloride in order to quantify trace amounts of these mixtures after their adsorption at water-solid interfaces. A fractional factorial design was then used to optimise the separation by ion-pair reversed-phase liquid chromatography as a function of six factors: the chain length of the tetraalkylammonium salt used as ion-pairing reagent which varied from methyl (C1) to n-propyl (C3); the concentration of this ion-pairing salt; the acetonitrile percentage in water used as organic modifier; the flow-rate; the temperature of analysis and also the sodium chloride concentration. The factorial design enabled in a limited number of analyses, not only to determine which factors had significant effects on retention times or on resolution between a pair of nonionic oligomers, but also to modelize and then find the interesting and rugged area where this resolution was optimal as well as the conditions where time of analysis was not prohibitive. After optimisation of HPLC analysis, we used a trace enrichment procedure to quantify very low concentrations of SDS and C12E9 polydisperse PEO in water. A C18 cartridge and a strong anionic exchange cartridge were coupled and the conditions of elution were optimised in order to obtain concentrated samples which were injected in the same eluent than the HPLC mobile phase. Under such conditions, we were able to quantify, in a single run, mixtures of anionic and nonionic surfactants at concentrations as low as 3.6 microg l(-1) for SDS and 2.5 microg l(-1) for each PEO oligomer in water.
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Affiliation(s)
- F I Portet
- Université de Rouen, Laboratoire d'Analyse des Systèmes Organiques Complexes, UPRES EA 2659, IRCOF et IFRMP, Evreux, France
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Rhode H, Schulze M, Cumme GA, Göhlert A, Blume E, Bublitz R, Schilling K, Horn A. Glycosylphosphatidylinositol-specific phospholipase D of human serum--activity modulation by naturally occurring amphiphiles. Biol Chem 2000; 381:471-85. [PMID: 10937880 DOI: 10.1515/bc.2000.062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The enzymatic properties of glycosylphosphatidylinositol-specific phospholipase D (EC 3.1.4.50) were characterized using a 6,000-fold purified enzyme. This was obtained in 100 microg amounts from human serum with a recovery of 35%. Pure alkaline phosphatase containing one anchor moiety per molecule was used as substrate. The enzyme is stimulated by n-butanol, but in contrast to other phospholipases this activation is not produced by a transphosphatidylation reaction. The previously reported non-linearity of the specific activity with respect to phospholipase concentration in the test was no longer observed upon purification, indicating inhibitor removal. The serum inhibitor(s) co-chromatograph with serum proteins and lipoproteins. The main part of the inhibitory activity was found in the lipid fraction after protein denaturation and can be subfractionated into acid phospholipids, cholesteryl esters and triacylglycerides. Added phosphatidyl-serine, phosphatidylinositol, phosphatidylglycerol, gangliosides, cholesteryl esters, and sphingomyelins turned out to be strong inhibitors, as well as phosphatidic acid. Phosphatidylethanolamine and various monoacylglycerols were found to be activators. The low glycosylphosphatidylinositol-specific phospholipase activity found in native serum did not increase significantly upon 90% removal of phospholipids by n-butanol. High serum concentrations of strongly inhibiting compounds, complex kinetic interactions among aggregates of these substances, and compartmentalization effects are discussed as possible reasons for the observed inactivity.
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Affiliation(s)
- H Rhode
- Institute of Biochemistry, Medical Faculty, Friedrich Schiller University, Jena, Germany
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Gehrhardt S, Blume E, Cumme GA, Bublitz R, Rhode H, Horn A. Gel chromatographic characterization of the hydrophobic interaction of glycosylphosphatidylinositol-alkaline phosphatase with detergents. Biol Chem 2000; 381:161-72. [PMID: 10746748 DOI: 10.1515/bc.2000.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The interaction of a glycosylphosphatidylinositol (GPI) protein with different detergents was studied for the first time with a purified protein. Four differently hydrophobic fractions of GPI-alkaline phosphatase (GPI-AP) from calf intestine were used as model proteins. The mode of interaction was determined by investigating (i) the self-aggregation behaviour of the GPI-AP fractions, (ii) the interference of detergents with GPI-AP binding to octyl-Sepharose, and (iii) the elution of GPI-AP bound to octyl-Sepharose. It was shown that polyoxyethylene-type detergents surprisingly interact much stronger than n-octylglucoside with GPI-AP, which is in contrast to the known behaviour of GPI-proteins in natural membranes. Gel filtration chromatography of Triton X-100 at concentrations above the critical micellar concentration yields three different micelle species with apparent molecular weights of about 166, 54, and 16 kDa. GPI-AP fraction II, which is shown to bear only one anchor per dimer, does not bind to any of these micelles. We demonstrate that a complex is formed containing about 150 Triton X-100 molecules and about 4700 molecules of water per molecule of GPI-AP dimer. The experimental findings are in accordance with a simple geometrical model based on the physical data of fatty acids and the arrangement, mean size, and shape of Triton X-100 molecules.
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Affiliation(s)
- S Gehrhardt
- Institute of Biochemistry, Medical Faculty, Friedrich Schiller University, Jena, Germany
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Chapter 19 Applications of liquid chromatography-mass spectrometry in environmental chemistry: characterization and determination of surfactants and their metabolites in water samples by modern mass spectrometric techniques. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0167-9244(00)80025-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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Huang Y, Mechref Y, Tian J, Gong H, Lennarz WJ, Novotny MV. A simple sample preparation for enhancing the sensitivity of mass spectrometric oligosaccharide determinations through the use of an adsorptive hydrophobic resin. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2000; 14:1233-1237. [PMID: 10918373 DOI: 10.1002/1097-0231(20000730)14:14<1233::aid-rcm16>3.0.co;2-p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A simple microadsorption technique is described to remove detergent additives from oligosaccharide samples before their mass spectrometric analysis. The described methodology has been validated with submicrogram quantities of contaminated glycoproteins. This procedure is applicable to investigating minute quantities of glycans in both the positive- and negative-ion mode of matrix-assisted laser desorption/ionization mass spectrometry.
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Affiliation(s)
- Y Huang
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
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Ayorinde FO, Elhilo E. Determination of the instrumental detection limits of commercial nonylphenol ethoxylates with a wide range of molecular masses using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 1999; 13:2166-2173. [PMID: 10523776 DOI: 10.1002/(sici)1097-0231(19991115)13:21<2166::aid-rcm770>3.0.co;2-i] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Recent interest in the environmental fate and impact of nonylphenol ethoxylates (NPEs) has necessitated the need for the development of specific, and yet efficient, analytical methodologies for their detection. Using seventeen commercial NPEs, all having the general formula 4-(C(9)H(19))-C(6)H(4)-(OCH(2)CH(2))(n)-OH, we have established minimum concentrations at which matrix-assisted laser desorption ionization (MALDI)/time-of-flight (TOF)/mass spectrometry (MS) can be used in their detection. The NPEs were dissolved in an acetonitrile/tetrahydrofuran (3:1) solvent system prior to mixing with the matrix (alpha-cyano-4-hydroxycinnamic acid, dissolved in acetonitrile/tetrahydrofuran) solution, and the resulting MALDI-TOF mass spectra produced mostly sodiated molecules [M + Na](+).For the NPEs in which the major components contain three to ten ethoxy units, the sodiated molecules were detected at a minimum analyte concentration of 10 &mgr;g/L, whereas those in which the major components contain eight to fifteen ethoxy units were detected at a minimum concentration of 30 &mgr;g/L. Those NPEs containing oligomers in excess of twenty ethoxy units were only detectable at much higher concentration. For examples, Surfonic(R) N-300, N-400, N550, N-700, N-800, and N-1000 had detection limits of (&mgr;g/L): 1000, 1600, 2000, 2600, 3500 and 4500, respectively. These variations in instrumental detection limits must be considered when analyzing environmental samples for the presence of nonylphenol ethoxylates. Copyright 1999 John Wiley & Sons, Ltd.
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Affiliation(s)
- FO Ayorinde
- Department of Chemistry, Howard University, Washington, DC 20059, USA
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