1
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Vanhinsbergh C, Hook EC, Oxby N, Dickman MJ. Optimization of orthogonal separations for the analysis of oligonucleotides using 2D-LC. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1227:123812. [PMID: 37454408 DOI: 10.1016/j.jchromb.2023.123812] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023]
Abstract
Oligonucleotides are commonly analysed using one dimensional chromatography (1D-LC) to resolve and characterise manufacturing impurities, structural isomers and (in respect to emerging oligonucleotide therapeutics) drug substance and drug product. Due to low selectivity and co-elution of closely related oligonucleotides using 1D-LC, analyte resolution is challenged. This leads to the requirement for improved analytical methods. Multidimensional chromatography has demonstrated utility in a range of applications as it increases peak capacity using orthogonal separations, however there are limited studies demonstrating the 2D-LC analysis of closely related oligonucleotides. In this study we optimised OGN size and sequence based separations using a variety of 1D-LC methods and coupled these orthogonal modes of chromatography within a 2D-LC workflow. Theoretical 2D-LC workflows were evaluated for optimal orthogonality using the minimum convex hull metric. The most orthogonal workflow identified in this study was ion-pair reversed phase using tributylammonium acetate (IP-RP-TBuAA) coupled with strong anion exchange in conjunction with sodium perchlorate (SAX-NaClO4) at high mobile phase pH. We developed a heart-cut (IP-RP-TBuAA)-(SAX-NaClO4) 2D-LC method for analysis of closely related size and sequence variant OGNs and OGN manufacturing impurities. The 2D-LC method resulted in an increased orthogonality and a reduction in co-elution (or close elution). Application of a UV based reference mapping strategy in conjunction with the 2D-LC method demonstrated a reduction in analytical complexity by reducing the reliance on mass based detection methods.
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Affiliation(s)
- Christina Vanhinsbergh
- Department of Chemical and Biological Engineering, Mappin Street, University of Sheffield, S1 3JD, UK
| | - Elliot C Hook
- GlaxoSmithKline, GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts SG1 2NY, UK
| | - Nicola Oxby
- GlaxoSmithKline, GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts SG1 2NY, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, Mappin Street, University of Sheffield, S1 3JD, UK.
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2
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Lievore G, Weldon R, Catani M, Cavazzini A, Müller-Späth T. Enrichment and recovery of oligonucleotide impurities by N-Rich twin-column continuous chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2022; 1209:123439. [DOI: 10.1016/j.jchromb.2022.123439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 10/15/2022]
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3
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Rentel C, Gaus H, Bradley K, Luu N, Kolkey K, Mai B, Madsen M, Pearce M, Bock B, Capaldi D. Assay, Purity, and Impurity Profile of Phosphorothioate Oligonucleotide Therapeutics by Ion Pair-High-Performance Liquid Chromatography-Mass Spectrometry. Nucleic Acid Ther 2022; 32:206-220. [PMID: 35238617 DOI: 10.1089/nat.2021.0056] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The relatively large molecular size, diastereoisomeric nature, and complex impurity profiles of therapeutic phosphorothioate oligonucleotides create significant analytical challenges for the quality control laboratory. To overcome the lack of selectivity inherent to traditional chromatographic approaches, an ion pair liquid chromatography-mass spectrometry (LCMS) method combining ultraviolet and mass spectrometry quantification was developed and validated for >35 different oligonucleotide drug substances and products, including several commercialized drugs. The selection of chromatographic and spectrometric conditions, data acquisition and processing, critical aspects of sample and buffer preparation and instrument maintenance, and results from method validation experiments are discussed.
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Affiliation(s)
- Claus Rentel
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Hans Gaus
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Kym Bradley
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Nhuy Luu
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Kimmy Kolkey
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Bao Mai
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Mark Madsen
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Megan Pearce
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Brandon Bock
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
| | - Daniel Capaldi
- Analytical Development Quality Control, Ionis Pharmaceuticals, Carlsbad, California, USA
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4
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Impurity profiling of siRNA by two-dimensional liquid chromatography-mass spectrometry with quinine carbamate anion-exchanger and ion-pair reversed-phase chromatography. J Chromatogr A 2021; 1643:462065. [PMID: 33780886 DOI: 10.1016/j.chroma.2021.462065] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 11/21/2022]
Abstract
A short RNA with the sequence of the antisense strand of Patisiran has been selected as test material for the investigation of its common impurities using three different two-dimensional liquid chromatography (2D-LC) platforms. On the one hand, a quinine (QN) carbamate-based weak anion-exchange (AX) stationary phase (QN-AX) and a classical C18 reversed phase (RP) stationary phase in ion-pair (IP) mode with tripropylammonium acetate, respectively, have been used in the first dimension (1D) to provide the selectivity for impurities formed during the synthesis of the RNA. In the next step, certain peaks of interest from 1D have been transferred by multiple-heart-cutting (MHC) into a 2D in which an ESI-MS-compatible non-ionpairing RP method has been used for desalting via a diverter valve to remove non-volatile phosphate buffer components and ion-pair agents, respectively. Thus, a sensitive electrospray-ionization quadrupole time of flight mass spectrometry (ESI-TOF-MS) analysis of resolved impurity peaks of the siRNA has become possible under MS-friendly conditions. With both 2D-LC setups, peak purity of the ON has been evaluated by selective comprehensive (high resolution) sampling of the main peak. In a third MHC 2D-LC approach, the QN-AX LC mode was online coupled with the IP-RPLC in the 2D using UV detection. It allows the separation of additional impurities which coeluted in the first dimension. The potential of these methods for comprehensive impurity profiling of ON therapeutics is illustrated and discussed.
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5
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Pourshahian S. THERAPEUTIC OLIGONUCLEOTIDES, IMPURITIES, DEGRADANTS, AND THEIR CHARACTERIZATION BY MASS SPECTROMETRY. MASS SPECTROMETRY REVIEWS 2021; 40:75-109. [PMID: 31840864 DOI: 10.1002/mas.21615] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Oligonucleotides are an emerging class of drugs that are manufactured by solid-phase synthesis. As a chemical class, they have unique product-related impurities and degradants, characterization of which is an essential step in drug development. The synthesis cycle, impurities produced during the synthesis and degradation products are presented and discussed. The use of liquid chromatography combined with mass spectrometry for characterization and quantification of product-related impurities and degradants is reviewed. In addition, sequence determination of oligonucleotides by gas-phase fragmentation and indirect mass spectrometric methods is discussed. © 2019 John Wiley & Sons Ltd. Mass Spec Rev.
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Affiliation(s)
- Soheil Pourshahian
- Janssen Pharmaceutical Companies of Johnson & Johnson, South San Francisco, CA, 94080
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6
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Roussis SG, Rodriguez AA, Rentel C. Determination of individual oligonucleotide impurities by small amine ion pair-RP HPLC MS and MS/MS: n - 1 impurities. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1169:122611. [PMID: 33706187 DOI: 10.1016/j.jchromb.2021.122611] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 02/09/2021] [Accepted: 02/18/2021] [Indexed: 12/01/2022]
Abstract
Ion pair-reversed phase (IP-RP) HPLC is one of the most widely used methods for the analysis of oligonucleotide impurities. The method is compatible with mass spectrometry and has been used to guide the development of improved synthesis and purification approaches. The ability to detect and characterize impurities depends on the reagents and the IP buffer system employed, as each can directly affect the degree of chromatographic separation and the sensitivity of detection by MS. Previous work in our laboratory has shown that small alkyl amines are suitable IP reagents for the analysis of impurities in phosphate diester oligonucleotides and can be used to differentiate among individual members of composite impurity families. The addition of an alkyl acid often further enhances peak separation, but at the detriment of ion signal. An improved method with increased chromatographic performance and sensitivity of detection is presented here. Improvements were mainly realized through the use of lower concentrations of small alkyl amine (i.e., 5 mM) and acid (0.5 mM) IP reagents, and ammonium bicarbonate (20 mM) as a buffer. The improved capabilities of the new method are demonstrated by separation of the individual components of the composite n - 1 impurity in a set of four production-scale batches of a single oligonucleotide. Addition of the alkyl acid resulted in resolution of most individual n - 1 impurities. The observed enhanced sensitivity of detection allowed multiple reaction monitoring (MRM) experiments, which were used to differentiate among unresolved impurities.
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Affiliation(s)
| | | | - Claus Rentel
- Ionis Pharmaceuticals, Carlsbad, CA 92010, United States
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7
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Sutton JM, Guimaraes GJ, Annavarapu V, van Dongen WD, Bartlett MG. Current State of Oligonucleotide Characterization Using Liquid Chromatography-Mass Spectrometry: Insight into Critical Issues. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1775-1782. [PMID: 32812756 DOI: 10.1021/jasms.0c00179] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
As interests increase in oligonucleotide therapeutics, there has been a greater need for analytical techniques to properly analyze and quantitate these biomolecules. This article looks into some of the existing chromatographic approaches for oligonucleotide analysis, including anion exchange, hydrophilic interaction liquid chromatography, and ion pair chromatography. Some of the key advantages and challenges of these chromatographic techniques are discussed. Colloid formation in mobile phases of alkylamines and fluorinated alcohols, a recently discovered analytical challenge, is discussed. Mass spectrometry is the method of choice to directly obtain structural information about oligonucleotide therapeutics. Mass spectrometry sensitivity challenges are reviewed, including comparison to other oligonucleotide techniques, salt adduction, and the multiple charge state envelope. Ionization of oligonucleotides through the charge residue model, ion evaporation model, and chain ejection model are analyzed. Therapeutic oligonucleotides have to undergo approval from major regulatory agencies, and the impurities and degradation products must be well-characterized to be approved. Current accepted thresholds for oligonucleotide impurities are reported. Aspects of the impurities and degradation products from these types of molecules are discussed as well as optimal analytical strategies to determine oligonucleotide related substances. Finally, ideas are proposed on how the field of oligonucleotide therapeutics may improve to aid in future analysis.
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Affiliation(s)
- J Michael Sutton
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, 250 W. Green Street, Athens, Georgia 30602-2352, United States
| | - Guilherme J Guimaraes
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, 250 W. Green Street, Athens, Georgia 30602-2352, United States
| | - Vidya Annavarapu
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, 250 W. Green Street, Athens, Georgia 30602-2352, United States
| | | | - Michael G Bartlett
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia College of Pharmacy, 250 W. Green Street, Athens, Georgia 30602-2352, United States
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8
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Catani M, De Luca C, Medeiros Garcia Alcântara J, Manfredini N, Perrone D, Marchesi E, Weldon R, Müller-Späth T, Cavazzini A, Morbidelli M, Sponchioni M. Oligonucleotides: Current Trends and Innovative Applications in the Synthesis, Characterization, and Purification. Biotechnol J 2020; 15:e1900226. [PMID: 32298041 DOI: 10.1002/biot.201900226] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/17/2020] [Indexed: 12/12/2022]
Abstract
Oligonucleotides (ONs) are gaining increasing importance as a promising novel class of biopharmaceuticals. Thanks to their fundamental role in gene regulation, they can be used to develop custom-made drugs (also called N-to-1) able to act on the gene expression at pre-translational level. With recent approvals of ON-based therapeutics by the Food and Drug Administration (FDA), a growing demand for high-quality chemically modified ONs is emerging and their market is expected to impressively prosper in the near future. To satisfy this growing market demand, a scalable and economically sustainable ON production is needed. In this paper, the state of the art of the whole ON production process is illustrated with the aim of highlighting the most promising routes toward the auspicated market-size production. In particular, the most recent advancements in both the upstream stage, mainly based on solid-phase synthesis and recombinant technology, and the downstream one, focusing on chromatographic techniques, are reviewed. Since ON production is projected to expand to the large scale, automatized multicolumn countercurrent technologies will reasonably be required soon to replace the current ones based on batch single-column operations. This consideration is supported by a recent cutting-edge application of continuous chromatography for the ON purification.
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Affiliation(s)
- Martina Catani
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, Ferrara, 44121, Italy
| | - Chiara De Luca
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, Ferrara, 44121, Italy
| | - João Medeiros Garcia Alcântara
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta,", Politecnico di Milano, via Mancinelli 7, Milano, 20131, Italy
| | - Nicolò Manfredini
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta,", Politecnico di Milano, via Mancinelli 7, Milano, 20131, Italy
| | - Daniela Perrone
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, Ferrara, 44121, Italy
| | - Elena Marchesi
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, Ferrara, 44121, Italy
| | - Richard Weldon
- ChromaCon AG, Technoparkstrasse 1, Zürich, 8005, Switzerland
| | | | - Alberto Cavazzini
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, Ferrara, 44121, Italy
| | - Massimo Morbidelli
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta,", Politecnico di Milano, via Mancinelli 7, Milano, 20131, Italy
| | - Mattia Sponchioni
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta,", Politecnico di Milano, via Mancinelli 7, Milano, 20131, Italy
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9
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Goyon A, Yehl P, Zhang K. Characterization of therapeutic oligonucleotides by liquid chromatography. J Pharm Biomed Anal 2020; 182:113105. [PMID: 32004766 DOI: 10.1016/j.jpba.2020.113105] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/21/2019] [Accepted: 01/08/2020] [Indexed: 12/27/2022]
Abstract
Marketed therapies in the pharmaceutical landscape are rapidly evolving and getting more diverse. Small molecule medicines have dominated in the past while antibodies have grown dramatically in recent years. However, the failure of traditional small and large molecules in accessing certain targets has led to increased R&D efforts to develop alternative modalities. Therapeutic oligonucleotides (ONs) can accurately be directed against their ribonucleic acid (RNA) target and represent a promising approach in previously untreated diseases. Established automated synthesis of ONs coupled with chemical improvements and the advance of new drug delivery technologies has recently brought ONs to a heightened level of interest. The first part of the present review describes the different classes of oligonucleotides, namely antisense oligonucleotide (ASO), small interfering RNA (siRNA), microRNA (miRNA), aptamer and immunostimulatory ON, with a focus on their delivery systems relevant for future analytical characterization. The second part reviews the typical impurities in therapeutic ON products. The third part discusses the use of historical methods anion exchange chromatography (AEX), ion-pair reversed phase liquid chromatography (IP-RP), mixed-mode chromatography (MMC) and recent analytical methodologies of hydrophilic interaction liquid chromatography (HILIC), two-dimensional liquid chromatography (2D-LC) mass spectrometry for the characterization of ASO and siRNA modalities. The effects of physicochemical properties of RPLC columns and ion-pair agents on ON separation are specifically addressed with possible future directions for method development provided. Finally, some innovative analytical developments for the analysis of siRNAs and their delivery materials to pave the way toward the use of multi-attribute methods in the near future are discussed.
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Affiliation(s)
- Alexandre Goyon
- Small Molecules Pharmaceutical Sciences, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Peter Yehl
- Small Molecules Pharmaceutical Sciences, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Kelly Zhang
- Small Molecules Pharmaceutical Sciences, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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10
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Kim TW, Papagiannis C, Capaldi D, McPherson AK, Mahdi F, Luu N, Rodriguez AA, Hoffmaster C, Serota D, Henry SP. Impurity Qualification Toxicology Study for a 2'-O-Methoxyethyl-Modified Antisense Inhibitor in Mice. Nucleic Acid Ther 2019; 30:14-21. [PMID: 31687889 DOI: 10.1089/nat.2019.0780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Safety assessment of drug impurities is a routine part of the drug development process. For oligonucleotide-based drugs, impurities can arise from impurities in starting materials, as by-products of the manufacturing process or from degradation, and are generally structurally similar to the parent oligonucleotide. To study the potential impact of impurities, a representative batch of a 2'-O-methoxyethyl (MOE) antisense oligonucleotide (ASO) was compared to batches of drug that were enriched with nine of the common impurities encountered with the chemical class. Mice were treated for 3 months with weekly subcutaneous injection of 10 or 30 mg/kg. The impurity content of the parent batch was 0.25%-2.5% of total drug substance. The enriched impurity mixtures contained from 3% to 10% of the various impurities. The expected common class effects were observed at the 30 mg/kg/week dose level in hematology, serum chemistry, and histopathology. However, there were no differences between the representative batch of material and those enriched with impurities. Based on these data, common oligonucleotide impurity studies do not appear to contribute to the overall toxicology profile.
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Affiliation(s)
- Tae-Won Kim
- Ionis Pharmaceuticals, Inc., Carlsbad, California
| | | | | | | | - Farah Mahdi
- Ionis Pharmaceuticals, Inc., Carlsbad, California
| | - Nhuy Luu
- Ionis Pharmaceuticals, Inc., Carlsbad, California
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11
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Roussis SG, Pearce M, Rentel C. Small alkyl amines as ion-pair reagents for the separation of positional isomers of impurities in phosphate diester oligonucleotides. J Chromatogr A 2019; 1594:105-111. [PMID: 30819437 DOI: 10.1016/j.chroma.2019.02.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/07/2019] [Accepted: 02/11/2019] [Indexed: 10/27/2022]
Abstract
In an effort to improve separation of impurities in oligonucleotide drugs, alkyl amines of different length and carbon content were evaluated as reagents in ion pair-reversed phase (IP-RP) HPLC with mass spectrometric detection. A range of columns was tested in combination with different buffers, ion-pair modifiers and varying pH adjustments. For phosphorothioate oligonucleotides, larger amines, like tributyl and hexyl amine provided the best chromatography, as small amines tended to broaden peaks due to the separation of diastereoisomers. For phosphate diester oligonucleotides, the best separations were obtained using small alkyl amines, like propyl-, isopropyl- and diethylamine. Conditions optimized for oligonucleotide sequence and type of impurity enabled full separation of the individual components of composite impurities, such as n-1, N3-(2-cyanoethyl)thymine (CNET), deaminated and 3-(2-oxopropyl)imidazopyrimidinone (OPC) impurities. The addition of long-chain alkyl acids like hexanoic acid to the IP buffer resulted in further improvements in peak separation.
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Affiliation(s)
| | - Megan Pearce
- Ionis Pharmaceuticals, 2855 Gazelle Ct., Carlsbad, CA 92010, United States
| | - Claus Rentel
- Ionis Pharmaceuticals, 2855 Gazelle Ct., Carlsbad, CA 92010, United States.
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12
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Capaldi D, Teasdale A, Henry S, Akhtar N, den Besten C, Gao-Sheridan S, Kretschmer M, Sharpe N, Andrews B, Burm B, Foy J. Impurities in Oligonucleotide Drug Substances and Drug Products. Nucleic Acid Ther 2017; 27:309-322. [PMID: 29125795 DOI: 10.1089/nat.2017.0691] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This white paper, which is the 10th in a series intended to address issues associated with the development of therapeutic oligonucleotides, examines the subject of product-related impurities. The authors consider chemistry and safety aspects and advance arguments in favor of platform approaches to impurity identification and qualification. Reporting, identification, and qualification thresholds suitable for product-related impurities of therapeutic oligonucleotides are proposed.
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Affiliation(s)
| | - Andy Teasdale
- 2 AstraZeneca UK Ltd. , Macclesfield, United Kingdom
| | - Scott Henry
- 1 Ionis Pharmaceuticals, Inc. , Carlsbad, California
| | - Nadim Akhtar
- 2 AstraZeneca UK Ltd. , Macclesfield, United Kingdom
| | | | | | | | - Neal Sharpe
- 5 Anavex Life Sciences Corp. , New York, New York
| | - Ben Andrews
- 6 GlaxoSmithKline , Stevenage, United Kingdom
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13
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El Zahar NM, Magdy N, El-Kosasy AM, Bartlett MG. Chromatographic approaches for the characterization and quality control of therapeutic oligonucleotide impurities. Biomed Chromatogr 2017; 32. [PMID: 28869310 DOI: 10.1002/bmc.4088] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/13/2017] [Accepted: 08/28/2017] [Indexed: 12/16/2022]
Abstract
Phosphorothioate (PS) oligonucleotides are a rapidly rising class of drugs with significant therapeutic applications. However, owing to their complex structure and multistep synthesis and purification processes, generation of low-level impurities and degradation products are common. Therefore, they require significant investment in quality control and impurity identification. This requires the development of advanced methods for analysis, characterization and quantitation. In addition, the presence of the PS linkage leads to the formation of chiral centers which can affect their biological properties and therapeutic efficiency. In this review, the different types of oligonucleotide impurities and degradation products, with an emphasis on their origin, mechanism of formation and methods to reduce, prevent or even eliminate their production, will be extensively discussed. This review will focus mainly on the application of chromatographic techniques to determine these impurities but will also discuss other approaches such as mass spectrometry, capillary electrophoresis and nuclear magnetic resonance spectroscopy. Finally, the chirality and formation of diastereomer mixtures of PS oligonucleotides will be covered as well as approaches used for their characterization and the application for the development of stereochemically-controlled PS oligonucleotides.
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Affiliation(s)
- N M El Zahar
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.,Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia, USA
| | - N Magdy
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - A M El-Kosasy
- Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Michael G Bartlett
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia, USA
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14
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Rodriguez AA, Cedillo I, McPherson AK. Conversion of adenine to 5-amino-4-pyrimidinylimidazole caused by acetyl capping during solid phase oligonucleotide synthesis. Bioorg Med Chem Lett 2016; 26:3468-71. [PMID: 27353533 DOI: 10.1016/j.bmcl.2016.06.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 10/21/2022]
Abstract
The acetyl capping reaction used throughout solid phase oligonucleotide synthesis is meant to minimize n-1 deletionmer impurities by terminating sequences that fail to couple to a phosphoramidite. However, the reaction is also responsible for the formation of a number of impurities. One capping-related impurity has an additional mass of 98amu from the parent oligonucleotide. The n+98 amu impurity was found to result from modification of an adenine nucleobase. The structure of the impurity was determined by preparation of an oligonucleotide enriched in n+98 amu, enzymatic digestion to individual nucleosides, isolation of the pure nucleoside+98 amu species, crystallization, and X-ray crystallographic analysis. The n+98 amu impurity is an oligonucleotide in which one adenine residue has been converted to 5-amino-4-pyrimidinylimidazole. The mechanism of formation of the impurity was investigated, and a mechanism is proposed.
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Affiliation(s)
| | - Isaiah Cedillo
- Ionis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, USA
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15
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Rodriguez AA, Cedillo I, Mowery BP, Gaus HJ, Krishnamoorthy SS, McPherson AK. Formation of the N(2)-acetyl-2,6-diaminopurine oligonucleotide impurity caused by acetyl capping. Bioorg Med Chem Lett 2014; 24:3243-6. [PMID: 24980055 DOI: 10.1016/j.bmcl.2014.06.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/06/2014] [Accepted: 06/09/2014] [Indexed: 11/25/2022]
Abstract
The acetyl 'capping' reaction routinely employed during phosphorothioate oligonucleotide synthesis has been implicated in the formation of an impurity species with a mass 41 amu greater than the expected oligonucleotide molecule. The impurity has been found to arise by conversion of a protected guanine nucleobase to N(2)-acetyl-2,6-diaminopurine. A two-part mechanism is proposed consisting of transamidation of the protecting group on guanine and substitution of guanine's O(6) atom.
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Affiliation(s)
- Andrew A Rodriguez
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, United States.
| | - Isaiah Cedillo
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, United States
| | - Brendan P Mowery
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, United States
| | - Hans J Gaus
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, United States
| | | | - Andrew K McPherson
- Isis Pharmaceuticals, Inc., 2855 Gazelle Ct., Carlsbad, CA 92010, United States
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16
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Abstract
The rapid development of therapeutic oligonucleotides (ONs) has created a need for in-depth characterization of ONs, beyond previous requirements. The natural migration to LC-MS requires the use of chromatography with MS-compatible eluents to introduce the large, highly charged biopolymers into the mass spectrometer. Most frequently this employs ion-pair reversed-phase liquid chromatography, which may leave gaps in the characterization, but these can be filled with the use of high-resolution ion-exchange chromatography. Several classes of isobaric isomers are among the impurities that will require further separation prior to MS analysis. This review shows how the use of ion exchange as an additional orthogonal analytical method can be used as standalone or interfaced with MS to achieve the highest possible analytical coverage in the characterization and quantification of impurities present in single- and double-stranded ON formulations. Some of these techniques have been in use for some time and the importance of others is just being recognized.
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17
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Thayer JR, Wu Y, Hansen E, Angelino MD, Rao S. Separation of oligonucleotide phosphorothioate diastereoisomers by pellicular anion-exchange chromatography. J Chromatogr A 2010; 1218:802-8. [PMID: 21216401 DOI: 10.1016/j.chroma.2010.12.051] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/17/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022]
Abstract
Synthetic oligonucleotides (ONs) are often prepared for development of therapeutic candidates. Among the modifications most often incorporated into therapeutic ONs are phosphorothioate (PT) linkages. The PT linkage introduces an additional chiral center at phosphorus to the chiral centers in D-ribose (and 2-deoxy-D-ribose) of the nucleic acid. Therefore, modified linkages can produce a diastereoisomer pair ([Rp] and [Sp]) at each PT linkage. These isomers are of identical length, sequence, charge and mass, and are not reliably separated by most chromatographic approaches (e.g., reversed phase chromatography) unless the ON is very short. Further these isomers are not distinguishable by single-stage mass spectrometry. During chromatography of a purified anti-NGF (nerve growth factor) aptamer containing 37 bases with 2 PT linkages by monolithic pellicular anion-exchange (pAE) column, we observed four components. The four components were postulated to be: (i) distinct folding conformations; (ii) fully and partially athioated aptamers; or (iii) PT diastereoisomers. Fractionation of the components, followed by de- and re-naturation failed to produce the original forms by refolding, eliminating option (i). Mass spectrometry of the fractionated, desalted samples revealed no significant mass differences, eliminating option (ii). Oxidative conversion of the PT to phosphodiester (PO) linkages in each of the purified components produced a single chromatographic peak, co-eluting with authentic PO aptamer, and having the PO aptamer mass. We conclude that the components resolved by pAE chromatography are diastereoisomers arising from the two PT linkages. Hence, pAE chromatography further enhances characterization of ON therapeutics harboring limited PT linkages and having up to 37 bases.
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Affiliation(s)
- James R Thayer
- Dionex Corporation, 445 Lakeside Drive, Sunnyvale, CA 94085, USA.
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18
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Sobkowski M. Chemistry and stereochemistry of internucleotide bond formation by the H-phosphonate method. NEW J CHEM 2010. [DOI: 10.1039/b9nj00679f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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19
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Seliger H. Protection of 5'-hydroxy functions of nucleosides. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2008; Chapter 2:Unit 2.3. [PMID: 18428836 DOI: 10.1002/0471142700.nc0203s00] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The 5-hydroxy group is the primary hydroxy group of nucleosides. It is mandatory to protect 5-hydroxyls in all methods of oligonucleotide synthesis that require nucleoside synthons. This unit discusses a wide variety of acid-labile and base-labile protecting groups, as well as enzymatic methods for 5-protection and deprotection.
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20
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Development of a modular system for detection of genetically modified organisms in food based on ligation-dependent probe amplification. Eur Food Res Technol 2007. [DOI: 10.1007/s00217-007-0790-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Eleuteri A, Cheruvallath ZS, Capaldi DC, Vasulinga DLC, Ravikumar T. Synthesis of Dimer Phosphoramidite Synthons for Oligodeoxyribonucleotide Phosphorothioates Using Diethyldithiocarbonate disulfide as an Efficient Sulfurizing Reagent. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319908044844] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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22
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Fountain KJ, Gilar M, Budman Y, Gebler JC. Purification of dye-labeled oligonucleotides by ion-pair reversed-phase high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 783:61-72. [PMID: 12450525 DOI: 10.1016/s1570-0232(02)00490-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Singly- and dually-labeled synthetic oligonucleotides were purified by ion-pair reversed-phase high-performance liquid chromatography using a 50x4.6-mm column packed with porous, 2.5 micrometer C(18) sorbent. We studied the mechanism of dye-labeled oligonucleotide retention in order to improve the quality of purification. By-products of oligonucleotide synthesis were characterized by liquid chromatography with mass spectrometry detection (LC-MS). We purified oligonucleotides labeled with 6-carboxyfluorescein (6FAM), hexachlorofluorescein (HEX), tetrachlorofluorescein (TET), carboxytetramethylrhodamine (TAMRA) and indodicarboxycyanine (Cy3) dyes, as well as dually-labeled TaqMan probes. Purification of a 0.1-micromole oligonucleotide synthesis in a single injection was demonstrated.
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23
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LeProust E, Zhang H, Yu P, Zhou X, Gao X. Characterization of oligodeoxyribonucleotide synthesis on glass plates. Nucleic Acids Res 2001; 29:2171-80. [PMID: 11353087 PMCID: PMC55452 DOI: 10.1093/nar/29.10.2171] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2000] [Revised: 03/11/2001] [Accepted: 03/20/2001] [Indexed: 11/14/2022] Open
Abstract
Achieving high fidelity chemical synthesis on glass plates has become increasingly important, since glass plates are substrates widely used for miniaturized chemical and biochemical reactions and analyses. DNA chips can be directly prepared by synthesizing oligonucleotides on glass plates, but the characterization of these micro-syntheses has been limited by the sub-picomolar amount of material available. Most DNA chip syntheses have been assayed using in situ coupling of fluorescent molecules to the 5'-OH of the synthesized oligonucleotides. We herein report a systematic investigation of oligonucleotide synthesis on glass plates with the reactions carried out in an automated DNA synthesizer using standard phosphoramidite chemistry. The analyses were performed using (32)P gel electrophoresis of the oligonucleotides cleaved from glass plates to provide product distribution profiles according to chain length of oligonucleotides. 5'-Methoxythymidine was used as the chain terminator, which permits assay of coupling reaction yields as a function of chain length growth. The results of this work reveal that a major cause of lower fidelity synthesis on glass plates is particularly inefficient reactions of the various reagents with functional groups close to glass plate surfaces. These problems cannot be detected by previous in situ fluorescence assays. The identification of this origin of low fidelity synthesis on glass plates should help to achieve improved synthesis for high quality oligonucleotide microarrays.
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Affiliation(s)
- E LeProust
- Department of Chemistry, University of Houston, Houston, TX 77204-5641, USA
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24
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Miyashita T, Yamada K, Kondo K, Mori K, Shinozuka K. Investigation of a facile synthetic method for phosphorothioate dimer synthons in oligonucleotide phosphorothioates synthesis. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2000; 19:955-62. [PMID: 10893714 DOI: 10.1080/15257770008033035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A facile synthetic method of a phosphorothioate dimer block was investigated. Dinucleoside phosphite triester intermediates were obtained in one-pot synthesis by the coupling of a protected nucleoside bearing free 5'-OH and a protected nucleoside bearing free 3'-OH in the presence of phosphorous trichloride (PCl3) and 1,2,4-triazole. The intermediates were easily sulfurized to afford the desired phosphorothioate dimer blocks in 33-64% overall yields.
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Affiliation(s)
- T Miyashita
- Chemistry Lab., Yamasa Corporation, Chiba, Japan.
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25
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Eleuteri A, Capaldi DC, Cole DL, Ravikumar VT. Oligodeoxyribonucleotide Phosphorothioates: Substantial Reduction of (N-1)-mer Content Through the Use of Trimeric Phosphoramidite Synthons. ACTA ACUST UNITED AC 1999. [DOI: 10.1080/15257779908043091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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26
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Krotz AH, Cole DL, Ravikumar VT. Synthesis of an antisense oligonucleotide targeted against C-raf kinase: efficient oligonucleotide synthesis without chlorinated solvents. Bioorg Med Chem 1999; 7:435-9. [PMID: 10220029 DOI: 10.1016/s0968-0896(98)00253-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
It is demonstrated that a solution of dichloroacetic acid in toluene removes dimethoxytrityl groups from the 5'-terminus of an antisense phosphorothioate oligodeoxyribonucleotide (ISIS 5132/CGP69846A) during synthesis on solid support cleanly and efficiently. It is therefore suggested to replace health hazardous dichloromethane which is typically used in oligonucleotide synthesis as solvent for DMTr-removal by toluene.
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Affiliation(s)
- A H Krotz
- Isis Pharmaceuticals Inc., Carlsbad, CA 92008, USA
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27
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Chen D, Yan Z, Cole DL, Srivatsa GS. Analysis of internal (n-1)mer deletion sequences in synthetic oligodeoxyribonucleotides by hybridization to an immobilized probe array. Nucleic Acids Res 1999; 27:389-95. [PMID: 9862956 PMCID: PMC148191 DOI: 10.1093/nar/27.2.389] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The purity of a drug substance can influence its toxicity and potency, so impurities must be specifically determined. In the case of synthetic oligodeoxyribonucleotide drugs, however, product complexity makes complete impurity speciation difficult. The goal of the present work was to develop a new analytical method for speciation of individual internal (n-1)mer impurities arising from formal nucleotide deletion in synthetic oligodeoxyribonucleotides. A complete series of oligodeoxyribonucleotide probes were designed, each complementary to an (n-1)mer deletion sequence of the drug in question. Glass plates were used as a solid support for individually immobilizing the entire probe array. The total mixture of internal (n-1) length impurities was isolated from a synthetic oligodeoxyribonucleotide by PAGE and labeled with 35S. Under stringently optimized conditions, only the perfectly sequence-matched oligodeoxyribonucleotide hybridized to each probe, while all other deletion sequences were removed by washing with buffer. The 35S signal intensity of the bound oligodeoxyribonucleotide was proportional to the concentration of each (n-1)mer deletion sequence in the analyte solution. This method has been applied to a number of synthetic phosphorothioate oligodeoxy-ribonucleotide lots and shown to be reliable for speciation and relative quantitation of the internal (n -1)mer deletion sequences present.
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Affiliation(s)
- D Chen
- Department of Development Chemistry, Isis Pharmaceuticals, 2292 Faraday Avenue, Carlsbad, CA 92008, USA.
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28
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Woźniak LA, Koziołkiewicz M, Kobylańska A, Stec WJ. Potassium peroxymonosulfate (oxone)--an efficient oxidizing agent for phosphothio compounds. Bioorg Med Chem Lett 1998; 8:2641-6. [PMID: 9873595 DOI: 10.1016/s0960-894x(98)00492-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Potassium peroxymonosulfate (oxone) is demonstrated as a versatile chemoselective and stereospecific oxidizing agent for phosphothio compounds. Its application in nucleotide chemistry is presented.
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Affiliation(s)
- L A Woźniak
- Polish Academy of Sciences, Department of Bioorganic Chemistry, Lódź, Poland
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29
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Olejnik J, Krzymañska-Olejnik E, Rothschild KJ. Photocleavable affinity tags for isolation and detection of biomolecules. Methods Enzymol 1998; 291:135-54. [PMID: 9661149 DOI: 10.1016/s0076-6879(98)91011-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- J Olejnik
- Department of Physics, Boston University, Massachusetts 02215, USA
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30
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Crain PF, McCloskey JA. Applications of mass spectrometry to the characterization of oligonucleotides and nucleic acids. Curr Opin Biotechnol 1998; 9:25-34. [PMID: 9503584 DOI: 10.1016/s0958-1669(98)80080-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mass spectrometry-based techniques continue to undergo active development for applications to nucleic acids, fueled by methods based on electrospray and matrix-assisted laser desorption ionization. In the past two years, notable advances have occurred in multiple interrelated areas, including sequencing techniques for oligonucleotides, approaches to mixture analysis, microscale sample handling and targeted DNA assays, and improvements in instrumentation for greater sensitivity and mass resolution.
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Affiliation(s)
- P F Crain
- University of Utah, Department of Medicinal Chemistry, Salt Lake City 84112-5820, USA.
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31
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Fearon KL, Hirschbein BL, Chiu CY, Quijano MR, Zon G. Phosphorothioate oligodeoxynucleotides: large-scale synthesis and analysis, impurity characterization, and the effects of phosphorus stereochemistry. CIBA FOUNDATION SYMPOSIUM 1998; 209:19-31; discussion 31-7. [PMID: 9383566 DOI: 10.1002/9780470515396.ch3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Large-scale synthesis of phosphorothioate oligodeoxynucleotides on Tentagel using a 'batch mode' synthesizer and beta-cyanoethyl phosphoramidite coupling followed by sulfurization with bis(O,O-diisopropoxy phosphinothioyl) disulfide (S-tetra) provides stepwise yields of 98-99% and results in phosphorothioate oligodeoxynucleotides that are 93-97% pure, as determined by PAGE, after reverse-phase high performance liquid chromatography (RP-HPLC) and 'downstream' processing. The purity of phosphorothioate oligodeoxynucleotides synthesized on Tentagel is significantly higher than those synthesized on controlled pore glass. Electrospray ionization mass spectrometry of the n-1 impurity isolated by preparative PAGE was used to establish that the n-1 impurity is a heterogeneous mixture of all possible single-deletion sequences, relative to the parent phosphorothioate oligodeoxynucleotide, and results from minor, though repetitive, imperfections in the synthesis cycle. Acid-catalysed depurination was found to occur both during the synthesis and during the post-synthesis detritylation, following RP-HPLC. Studies of hybridization affinity and biological mechanism of action using independently synthesized n-1 phosphorothioate oligodeoxynucleotides relative to the 15 mer LR-3280 showed that, in this case, the majority of the n-1 sequences had more than a 10 degrees C decrease in melting temperature with sense RNA compared to the n-mer, and they did not cause detectable cleavage of RNA by RNase H in HL-60 human promyelocytic leukaemia cells. P stereoregular phosphorothioate oligodeoxynucleotides are not significantly more active than their stereorandom counterparts and thus their use in clinical studies seems unwarranted.
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Affiliation(s)
- K L Fearon
- Lynx Therapeutics Inc., Hayward, CA 94545, USA
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32
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Liquid chromatography–mass spectrometry in nucleoside, nucleotide and modified nucleotide characterization. J Chromatogr A 1998. [DOI: 10.1016/s0021-9673(97)00902-3] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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33
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Krotz AH, Klopchin P, Cole DL, Ravikumar VT. Improved Impurity Profile of Phosphorothioate Oligonucleotides Through the Use of Dimeric Phosphoramidite Synthons. ACTA ACUST UNITED AC 1997. [DOI: 10.1080/07328319708006244] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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34
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Ball RW, Packman LC. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry as a rapid quality control method in oligonucleotide synthesis. Anal Biochem 1997; 246:185-94. [PMID: 9073355 DOI: 10.1006/abio.1997.2003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Oligonucleotide synthesis is a major activity for a large number of laboratories throughout the world. Dimethoxytrityl-deprotection monitors on instruments give the operator a measure of synthetic efficiency, but cannot be considered as a reliable indicator of the final quality of the cleaved and deprotected oligonucleotide. We have therefore adapted and developed methods of analyzing oligonucleotides by matrix-assisted laser desorption ionization mass spectrometry to the quality control situation, resulting in the ability to analyze 20 oligonucleotides up to at least 40 bases long in less than an hour. Most oligonucleotides can be analyzed automatically using the automatic scanning feature of a Kratos MALDI III analyzer.
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Affiliation(s)
- R W Ball
- Department of Biochemistry, Cambridge Centre for Molecular Recognition, Cambridge University, United Kingdom
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35
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Iyer RP, Yu D, Habus I, Ho NH, Johnson S, Devlin T, Jiang Z, Zhou W, Xie J, Agrawal S. N-pent-4-enoyl (PNT) group as a universal nucleobase protector: Applications in the rapid and facile synthesis of oligonucleotides, analogs, and conjugates. Tetrahedron 1997. [DOI: 10.1016/s0040-4020(97)00048-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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36
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Krotz AH, Klopchin P, Cole DL, Ravikumar VT. Phosphorothioate oligonucleotides: Largely reduced (N-1)-mer and phosphodiester content through the use of dimeric phosphoramidite synthons. Bioorg Med Chem Lett 1997. [DOI: 10.1016/s0960-894x(96)00573-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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37
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Kwiatkowski M, Nilsson M, Landegren U. Synthesis of full-length oligonucleotides: cleavage of apurinic molecules on a novel support. Nucleic Acids Res 1996; 24:4632-8. [PMID: 8972847 PMCID: PMC146293 DOI: 10.1093/nar/24.23.4632] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The synthesis of oligodeoxynucleotides is marred by several problems that contribute to the formation of defective molecules. This in turn seriously limits the usefulness of such reagents in DNA diagnostics, molecular cloning, DNA structural analysis and in antisense therapy. In particular, depurination reactions during the cyclical steps of synthesis lead to strand scission during cleavage of the completed molecules from the support. Here we present a remedy to this problem: a novel disiloxyl linkage that connects oligonucleotides to the support withstands reaction conditions that allow the removal of the 5' parts of any depurinated molecules. This ensures that all molecules that preserve the 5' protecting group when cleaved from the support will have both correct 3'- and 5'-ends. We demonstrate the application of the support for synthesis of padlock probe molecules.
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Affiliation(s)
- M Kwiatkowski
- Department of Medical Genetics, Uppsala University, Sweden.
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38
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Paul CH, Royappa AT. Acid binding and detritylation during oligonucleotide synthesis. Nucleic Acids Res 1996; 24:3048-52. [PMID: 8760892 PMCID: PMC146054 DOI: 10.1093/nar/24.15.3048] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Under the conditions normally used for detritylation in oligonucleotide synthesis, the haloacetic acid binds strongly to the oligonucleotide. Acetonitrile also forms a complex with the deblocking acid, in competition with the oligonucleotide, and drastically slows detritylation. Incomplete removal of acetonitrile during the deblock step may slow the kinetics enough to result in incomplete detritylation of the oligonucleotide. Acid binding to the growing oligonucleotide causes striking chromatographic effects in the presence of high oligonucleotide mass densities. In packed-bed column reactors, at low linear velocities, the acid binding almost completely depletes free acid from the deblocking solution. This results in an advancing zone within which the oligonucleotide is saturated with acid. Detritylation occurs mostly in a narrow band at the front of the advancing saturated zone. Increasing the DCA concentration in order to achieve quick saturation can give faster and more complete detritylation while minimizing the exposure time of the oligonucleotide to acid.
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Affiliation(s)
- C H Paul
- PerSeptive Biosystems, Framingham, MA 01701, USA
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39
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Földes-Papp Z, Birch-Hirschfeld E, Eickhoff H, Baumann G, Peng WG, Biber T, Seydel R, Kleinschmidt AK, Seliger H. Fractals for multicyclic synthesis conditions of biopolymers. Examples of oligonucleotide synthesis measured by high-performance capillary electrophoresis and ion-exchange high-performance liquid chromatography. J Chromatogr A 1996; 739:431-47. [PMID: 8765856 DOI: 10.1016/0021-9673(96)00060-x] [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: 02/02/2023]
Abstract
We have developed models of patterns for nucleotide chain growth. These patterns are measurable by high-performance capillary electrophoresis and ion-exchange high-performance liquid chromatography in crude products of solid-phase synthesized 30mer and 65mer oligodeoxyribonucleotide target sequences N. We introduce mathematical methods for finding characteristic values d(o) and p(o) for constant chemical modes of growth as well as d and p for non-constant chemical modes of growth (d = probability of propagation, p = probability of termination). These methods are employed by presenting the accompanying computer software developed by us in C code, Mathematica R languages, and Fortran. Characteristic values of the parameters d, p, and the target nucleotide length N describe the complete composition of the crude product. From this we have developed the relation 2 - [N/(N - 1)]/Da, measurable(N,d) as a universal quantitative measure for multicyclic synthesis conditions (D, fractal dimension and similarity exponent, respectively). We use this mathematical treatment to compare the efficiency of oligodeoxyribonucleotide syntheses of different target length N on polymer support materials. Further, we analyze selected syntheses of short and long oligodeoxyribonucleotides as well as single-stranded DNA sequences by well-known empirical autocorrelation, fast Fourier transformation, and embedding dimension techniques.
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40
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Olejnik J, Krzymańska-Olejnik E, Rothschild KJ. Photocleavable biotin phosphoramidite for 5'-end-labeling, affinity purification and phosphorylation of synthetic oligonucleotides. Nucleic Acids Res 1996; 24:361-6. [PMID: 8628663 PMCID: PMC145639 DOI: 10.1093/nar/24.2.361] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We report the design, synthesis and evaluation of a non-nucleosidic photocleavable biotin phosphoramidite (PCB-phosphoramidite) which provides a simple method for purification and phosphorylation of oligonucleotides. This reagent introduces a photocleavable biotin label (PCB) on the 5'-terminal phosphate of synthetic oligonucleotides and is fully compatible with automated solid support synthesis. HPLC analysis shows that the PCB moiety is introduced predominantly on full-length sequences and is retained during cleavage of the synthetic oligonucleotide from the solid support and during subsequent deprotection with ammonia. The full-length 5-PCB-labeled oligonucleotide can then be selectively isolated from the crude oligonucleotide mixture by incubation with immobilized streptavidin. Upon irradiation with 300-350 nm light the 5'-PCB moiety is cleaved with high efficiency in <4 min, resulting in rapid release of affinity-purified 5'-phosphorylated oligonucleotides into solution. 5'-PCB-labeled oligonucleotides should be useful in a variety of applications in molecular biology, including cassette mutagenesis and PCR. As an example, PCB-phosphoramidite has been used for the synthesis, purification and phosphorylation of 50-and 60mer oligonucleotides.
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Affiliation(s)
- J Olejnik
- Department of Physics and Molecular Biophysics Laboratory, Boston University, MA 02215, USA
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