1
|
Grossert JS, Crowell AMJ, Boschi D, Lolli ML, White RL. Tandem mass spectrometry of homologous 3-hydroxyfurazan and nitrile amino acids: Analysis of cooperative interactions and fragmentation processes. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5043. [PMID: 38789127 DOI: 10.1002/jms.5043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/23/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024]
Abstract
The assignment of structure by tandem mass spectrometry (MS/MS) relies on the interpretation of the fragmentation behavior of gas-phase ions. Mass spectra were acquired for a series of heterocyclic mimetics of acidic amino acids and a related series of nitrile amino acids. All amino acids were readily protonated or deprotonated by electrospray ionization (ESI), and distinctive fragmentation processes were observed when the ions were subjected to collision-induced dissociation (CID). The deprotonated heterocycles showed bond cleavages of the 3-hydroxyfurazan ring with formation of oxoisocyanate and the complementary deprotonated nitrile amino acid. Further fragmentation of the deprotonated nitrile amino acids was greatly dependent on the length of the alkyl nitrile side chain. Competing losses of CO2 versus HCN occurred from α-cyanoglycinate (shortest chain), whereas water was lost from 2-amino-5-cyanopentanoate (longest chain). Interestingly, loss of acrylonitrile by a McLafferty-type fragmentation process was detected for 2-amino-4-cyanobutanoate, and several competing processes were observed for β-cyanoalanate. In one process, cyanide ion was formed either by consecutive losses of ammonia, carbon dioxide, and acetylene or by a one-step decarboxylative elimination. In another, complementary ions were obtained from β-cyanoalanate by loss of acetonitrile or HN=CHCO2H. Fragmentation of the protonated 3-hydroxyfurazan and nitrile amino acids resulted in the cumulative loss (H2O + CO), a loss that is commonly observed for protonated aliphatic α-amino acids. Overall, the distinct fragmentation behavior of the multifunctional 3-hydroxyfurazan amino acids correlated with the charged site, whereas fragmentations of the deprotonated nitrile amino acids showed cooperative interactions between the nitrile and the carboxylate groups.
Collapse
Affiliation(s)
- J Stuart Grossert
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Andrew M J Crowell
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Donatella Boschi
- Dipartimento di Scienza e Tecnologia del Farmaco (DSTF), Università degli Studi di Torino, Torino, Italy
| | - Marco L Lolli
- Dipartimento di Scienza e Tecnologia del Farmaco (DSTF), Università degli Studi di Torino, Torino, Italy
| | - Robert L White
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
2
|
Grossert JS, Boschi D, Lolli ML, White RL. Intramolecular interactions and the neutral loss of ammonia from collisionally activated, protonated ω-aminoalkyl-3-hydroxyfurazans. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2024; 30:38-46. [PMID: 37974410 PMCID: PMC10809737 DOI: 10.1177/14690667231214672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023]
Abstract
Gas phase fragmentation reactions of monoprotonated 4-(3-aminopropyl)- and 4-(4-aminobutyl)-3-hydroxyfurazan were investigated to examine potential interactions between functional groups. The two heterocyclic alkyl amines were ionized by electrospray ionization (ESI, positive mode) and fragmented using tandem mass spectrometry (MS/MS). The fragmentation pathways were characterized using pseudo MS3 experiments, precursor-ion scans, and density functional computations. For both heterocyclic ions, loss of ammonia was the only fragmentation process observed at low collision energies. Computational analysis indicated that the most feasible mechanism was intramolecular nucleophilic displacement of ammonia from the protonated ω-aminoalkyl side chain by N5 of the furazan ring. The alkylated nitrogen in the resulting bicyclic product ion facilitated N-O bond cleavage; subsequent neutral losses of nitric oxide (NO) and carbon monoxide (CO) occurred by homolytic bond cleavages. Next in the multistep sequence, neutral loss of ethylene from a radical cation was observed. A less favorable, competing fragmentation pathway of protonated 4-(3-aminopropyl)-3-hydroxyfurazan was consistent with cleavage of the 3-hydroxyfurazan ring and losses of NO and CO. Overall, the similar fragmentation behavior found for protonated 4-(3-aminopropyl)- and 4-(4-aminobutyl)-3-hydroxyfurazan differed from that previously characterized for furazan analogs with shorter alkyl chains. These observations demonstrate that a small change in the structure of multifunctional, heterocyclic alkyl amines may significantly influence interactions between distinct functional groups and the nature of the fragmentation process.
Collapse
Affiliation(s)
- J. Stuart Grossert
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Donatella Boschi
- Dipartimento di Scienza e Tecnologia del Farmaco (DSTF), Università degli Studi di Torino, Torino, Italy
| | - Marco L. Lolli
- Dipartimento di Scienza e Tecnologia del Farmaco (DSTF), Università degli Studi di Torino, Torino, Italy
| | - Robert L. White
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
3
|
New approach for barbiturates, phenytoin, methyprylon and glutethimide determination and fragmentation (UHPLC-MS/MS). J Pharm Biomed Anal 2023; 228:115318. [PMID: 36868027 DOI: 10.1016/j.jpba.2023.115318] [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: 12/18/2022] [Revised: 02/15/2023] [Accepted: 02/24/2023] [Indexed: 03/03/2023]
Abstract
Barbiturates which are old pharmaceutical drugs are still widely used in medical treatment of epilepsy and for general anesthesia. To date, more than 2500 different barbituric acid analogs have been synthesized, and 50 of them were introduced into medical use over the last century. Due to their highly addictive properties, pharmaceuticals containing barbiturates are under strict control in many countries. However, by considering the worldwide problem with new psychoactive substances (NPS) the introduction of new designer barbiturate analogs into the dark market might serve a serious public health problem in the near future. For this reason there is an increasing need for application methods for barbiturates monitoring in biological samples. The UHPLC-QqQ-MS/MS method for determination of 15 barbiturates, phenytoin, methyprylon and glutethimide was developed and fully validated. The biological sample volume was reduced to only 50 µL. A simple LLE (pH 3 with ethyl acetate) was successfully applied. The lower LOQ was 10 ng/mL. The method enables differentiation of structural isomers: hexobarbital and cyclobarbital; as well as amobarbital and pentobarbital. Chromatographic separation was achieved with the use of the alkaline mobile phase (pH 9) and Acquity UPLC BEH C18 column. Furthermore, the novel fragmentation mechanism of barbiturates was proposed, which may have a great impact in identification of novel barbiturates analogs introduced to illegal marketplaces. The presented technique has a great potential to be applied in forensic, clinical and veterinary toxicological laboratories, as was evidenced by the positive results of international proficiency tests.
Collapse
|
4
|
Koopman J, Grimme S. Calculation of Mass Spectra with the QCxMS Method for Negatively and Multiply Charged Molecules. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:2226-2242. [PMID: 36343304 DOI: 10.1021/jasms.2c00209] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Analysis and validation of a mass spectrometry (MS) experiment are usually performed by comparison to reference spectra. However, if references are missing, measured spectra cannot be properly matched. To close this gap, the Quantum Chemical Mass Spectrometry (QCxMS) program has been developed. It enables fully automatic calculations of electron ionization (EI) and positive ion collision-induced dissociation (CID) mass spectra of singly charged molecular ions. In this work, the extension to negative and multiple ion charge for the CID run mode is presented. QCxMS is now capable of calculating structures carrying any charge, without the need for pretabulated fragmentation pathways or machine learning of database spectra. Mass spectra of four single negatively charged and two multiple positively charged organic ions with molecular sizes from 12 to 92 atoms were computed and compared to reference spectra. The underlying Born-Oppenheimer molecular dynamics (MD) calculations were conducted using the semiempirical quantum mechanical GFN2-xTB method, while for some small molecules, ab initio DFT-based MD simulations were performed. Detailed insights into the fragmentation pathways were gained, and the effects of the computed charge assignments on the resulting spectrum are discussed. Especially for the negative ion mode, the influence of the deprotonation site to create the anion was found to be substantial. Doubly charged fragments could successfully be calculated fully automatically for the first time, while higher charged structures introduced severe assignment problems. Overall, this extension of the QCxMS program further enhances its applicability and underlines its value as a sophisticated toolkit for CID-based tandem MS structure elucidation.
Collapse
Affiliation(s)
- Jeroen Koopman
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115Bonn, Germany
| |
Collapse
|
5
|
Schnegotzki R, Koopman J, Grimme S, Süssmuth RD. Quantum Chemistry-based Molecular Dynamics Simulations as a Tool for the Assignment of ESI-MS/MS Spectra of Drug Molecules. Chemistry 2022; 28:e202200318. [PMID: 35235707 PMCID: PMC9325386 DOI: 10.1002/chem.202200318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Indexed: 11/08/2022]
Abstract
In organic mass spectrometry, fragment ions provide important information on the analyte as a central part of its structure elucidation. With increasing molecular size and possible protonation sites, the potential energy surface (PES) of the analyte can become very complex, which results in a large number of possible fragmentation patterns. Quantum chemical (QC) calculations can help here, enabling the fast calculation of the PES and thus enhancing the mass spectrometry-based structure elucidation processes. In this work, the previously unknown fragmentation pathways of the two drug molecules Nateglinide (45 atoms) and Zopiclone (51 atoms) were investigated using a combination of generic formalisms and calculations conducted with the Quantum Chemical Mass Spectrometry (QCxMS) program. The computations of the de novo fragment spectra were conducted with the semi-empirical GFNn-xTB (n=1, 2) methods and compared against Orbitrap measured electrospray ionization (ESI) spectra in positive ion mode. It was found that the unbiased QC calculations are particularly suitable to predict non-evident fragment ion structures, sometimes contrasting the accepted generic formulation of fragment ion structures from electron migration rules, where the "true" ion fragment structures are approximated. For the first time, all fragment and intermediate structures of these large-sized molecules could be elucidated completely and routinely using this merger of methods, finding new undocumented mechanisms, that are not considered in common rules published so far. Given the importance of ESI for medicinal chemistry, pharmacokinetics, and metabolomics, this approach can significantly enhance the mass spectrometry-based structure elucidation processes and contribute to the understanding of previously unknown fragmentation pathways.
Collapse
Affiliation(s)
- Romina Schnegotzki
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| | - Jeroen Koopman
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115, Bonn, Germany
| | - Roderich D Süssmuth
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| |
Collapse
|
6
|
Rozali NL, Tahir NI, Hassan H, Othman A, Ramli US. Identification of amines, amino and organic acids in oil palm (Elaeis guineensis Jacq.) spear leaf using GC- and LC/Q-TOF MS metabolomics platforms. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
7
|
Kokotou MG. Study of the Fragmentation Pathways of Sulfonamides by High-resolution Mass Spectrometry: Application to their Detection in Plasma by Direct Infusion. CURR PHARM ANAL 2020. [DOI: 10.2174/1573412915666181205115350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
The high resolving and accuracy power of the HRMS instrument enabled us to
identify the product ions and to propose detailed fragmentation pathways and diagnostic fragment ions.
Methods:
In the present work, the fragmentation pathways of five sulfonamides antibiotics, namely
sulfamerazine, sulfathiazole, sulfadiazine, sulfadimethoxine and sulfamethoxazole, by High-Resolution
Mass Spectrometry (HRMS) are presented. The HRMS spectra were recorded with a Q-TOF (Time of
Flight) spectrometer with Electrospray Ionization (ESI) in both negative and positive mode.
Results:
Specific characteristic ions for each one of the sulfonamide antibiotics under positive ESI
mode are proposed for the first time. Fragment ions of this particular class of analytes may be used to
rapidly identify compounds with common structural features.
Conclusion:
The direct infusion of plasma samples, avoiding any prior chromatographic steps, to identify
the existence of sulfonamide antibiotics is demonstrated herein.
Collapse
Affiliation(s)
- Maroula G. Kokotou
- Department of Food Science and Human Nutrition, Chemical Laboratories, Agricultural University of Athens, Iera Odos 75, Athens 11855, Greece
| |
Collapse
|
8
|
Mansor NA, Tay KS. Potential toxic effects of chlorination and UV/chlorination in the treatment of hydrochlorothiazide in the water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 714:136745. [PMID: 31982754 DOI: 10.1016/j.scitotenv.2020.136745] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
Chlorination is a common disinfection method in water treatment. This method can be converted into an advanced oxidation process by incorporating UV irradiation during water treatment. This study investigated the degradation of hydrochlorothiazide (HCTZ) by chlorination and UV/chlorination in water. HCTZ is a diuretic medication that has been frequently detected in wastewater. For chlorination, the second-order rate constant for the reaction between HCTZ with free available chlorine was found to increase with increasing pH from 5 to 8 due to the increase of the anionic HCTZ fraction. UV/chlorination was found to be more efficient in removing HCTZ as compared with chlorination due to the presence of reactive radical species such as hydroxyl radicals. For transformation by-products, chlorination was found to produce two by-products via chlorination and hydroxylation reactions that occurred at the aromatic ring of HCTZ. For UV/chlorination, an additional by-product formed through a radical reaction at the heterocyclic moiety of HCTZ was detected. Based on the Escherichia coli inhibition study, chlorination and UV/chlorination were found to increase the toxicity of the HCTZ solution. This result indicated that even UV/chlorination showed higher effectiveness in removing HCTZ; however, it also has the potential to generate toxic by-products and effluent.
Collapse
Affiliation(s)
- Nur Adawiyah Mansor
- Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kheng Soo Tay
- Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| |
Collapse
|
9
|
Ki NY, Hur J, Kim BH, Kim KH, Moon BJ, Oh HB, Hong J. Rapid screening of sulfonamides in dietary supplements based on extracted common ion chromatogram and neutral loss scan by LC-Q/TOF-mass spectrometry. J Food Drug Anal 2019; 27:164-174. [PMID: 30648569 PMCID: PMC9298626 DOI: 10.1016/j.jfda.2018.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/01/2018] [Accepted: 08/13/2018] [Indexed: 11/17/2022] Open
Abstract
There is an increasing amount of dietary supplements that are adulterated with diuretics and anti-diabetic drugs; this has become a global problem due to the wide distribution of dietary supplements and the serious negative health effects of the adulterants. In this study, a rapid screening method was developed for detection and confirmation of 35 sulfonamides in supplements by ultra-high performance liquid chromatography quadrupole/ time of flight mass spectrometry. For effective extraction of sulfonamides from dietary supplements, four extraction protocols including HLB and WAX solid-phase extraction, Quick Easy Cheap Effective Rugged and Safe method, and pH-controlled liquid–liquid extraction were evaluated, and pH-controlled liquid–liquid extraction method was shown to be the most effective with high recovery efficiency and low matrix effect. Rapid separation of 35 sulfonamides was achieved with the UHPLC C18 column (150 × 2.1 mm, 1.7 um) within 7 min using ammonium acetate aqueous solution (pH 8) and acetonitrile as the mobile phase. From the MS/MS spectra of sulfonamides, common ions (m/z 77.9650 [SO2N]− and m/z 79.9812 [SO2NH2]−) and neutral molecule loss fragments (HCl and SO2) were observed according to their structural characteristics. Extracted common ion chromatograms and neutral loss scan of these characteristic fragments could effectively apply for rapid screening of sulfonamides in various types of supplements. A reduced mass tolerance window of ±5 ppm was useful for detecting targeted and untargeted sulfonamides and could avoid false positive and false negative results. Overall calibration curves within dynamic range for all targets were shown to be linear with a correlation coefficient R2 > 0.995 and limits of detection ranged from 0.04 to 11.18 ng/g for all sulfonamides. The established method was successfully applied for screening and confirmation of sulfonamides in various supplements. The developed method will be helpful for the identification of sulfonamide diuretics and anti-diabetics in dietary supplements, promoting public health and consumer safety.
Collapse
|
10
|
Development of an HPLC-MS/MS method to determine janagliflozin in human plasma and urine: application in clinical study. Bioanalysis 2018; 10:1439-1454. [PMID: 30182735 DOI: 10.4155/bio-2018-0129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
AIM Janagliflozin is a novel, orally selective sodium-glucose co-transporter-2 (SGLT2) inhibitor, which showed good efficacy and safety in preclinical study. The objective of this study is to develop and validate the HPLC-MS/MS method to determine janagliflozin in both of human urine and plasma. METHODS Janagliflozin was separated on Waters Xbridge Phenyl C18 column and detected on API 4000 tandem mass spectrometer with ESI source in negative mode. RESULTS This method provided good linearity in the range of 5-5000 ng/ml and 5-1000 ng/ml in plasma and urine. The matrix effect and extraction recoveries across three concentration levels were consistent. CONCLUSION This validated method is reliable and has been successfully applied to a first-in-human trial of janagliflozin in Chinese subjects.
Collapse
|
11
|
De Vijlder T, Valkenborg D, Lemière F, Romijn EP, Laukens K, Cuyckens F. A tutorial in small molecule identification via electrospray ionization-mass spectrometry: The practical art of structural elucidation. MASS SPECTROMETRY REVIEWS 2018; 37:607-629. [PMID: 29120505 PMCID: PMC6099382 DOI: 10.1002/mas.21551] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 05/10/2023]
Abstract
The identification of unknown molecules has been one of the cornerstone applications of mass spectrometry for decades. This tutorial reviews the basics of the interpretation of electrospray ionization-based MS and MS/MS spectra in order to identify small-molecule analytes (typically below 2000 Da). Most of what is discussed in this tutorial also applies to other atmospheric pressure ionization methods like atmospheric pressure chemical/photoionization. We focus primarily on the fundamental steps of MS-based structural elucidation of individual unknown compounds, rather than describing strategies for large-scale identification in complex samples. We critically discuss topics like the detection of protonated and deprotonated ions ([M + H]+ and [M - H]- ) as well as other adduct ions, the determination of the molecular formula, and provide some basic rules on the interpretation of product ion spectra. Our tutorial focuses primarily on the fundamental steps of MS-based structural elucidation of individual unknown compounds (eg, contaminants in chemical production, pharmacological alteration of drugs), rather than describing strategies for large-scale identification in complex samples. This tutorial also discusses strategies to obtain useful orthogonal information (UV/Vis, H/D exchange, chemical derivatization, etc) and offers an overview of the different informatics tools and approaches that can be used for structural elucidation of small molecules. It is primarily intended for beginning mass spectrometrists and researchers from other mass spectrometry sub-disciplines that want to get acquainted with structural elucidation are interested in some practical tips and tricks.
Collapse
Affiliation(s)
- Thomas De Vijlder
- Pharmaceutical Development & Manufacturing Sciences (PDMS)Janssen Research & DevelopmentBeerseBelgium
| | - Dirk Valkenborg
- Interuniversity Institute for Biostatistics and Statistical BioinformaticsHasselt UniversityDiepenbeekBelgium
- Center for Proteomics (CFP)University of AntwerpAntwerpBelgium
- Flemish Institute for Technological Research (VITO)MolBelgium
| | - Filip Lemière
- Center for Proteomics (CFP)University of AntwerpAntwerpBelgium
- Department of Chemistry, Biomolecular and Analytical Mass SpectrometryUniversity of AntwerpAntwerpBelgium
| | - Edwin P. Romijn
- Pharmaceutical Development & Manufacturing Sciences (PDMS)Janssen Research & DevelopmentBeerseBelgium
| | - Kris Laukens
- Department of Mathematics and Computer Science, Advanced Database Research and Modelling (ADReM)University of AntwerpAntwerpBelgium
- Biomedical Informatics Network Antwerp (Biomina)University of AntwerpAntwerpBelgium
| | - Filip Cuyckens
- Pharmacokinetics, Dynamics & MetabolismJanssen Research & DevelopmentBeerseBelgium
| |
Collapse
|
12
|
Kind T, Tsugawa H, Cajka T, Ma Y, Lai Z, Mehta SS, Wohlgemuth G, Barupal DK, Showalter MR, Arita M, Fiehn O. Identification of small molecules using accurate mass MS/MS search. MASS SPECTROMETRY REVIEWS 2018; 37:513-532. [PMID: 28436590 PMCID: PMC8106966 DOI: 10.1002/mas.21535] [Citation(s) in RCA: 249] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/17/2017] [Accepted: 03/18/2017] [Indexed: 05/03/2023]
Abstract
Tandem mass spectral library search (MS/MS) is the fastest way to correctly annotate MS/MS spectra from screening small molecules in fields such as environmental analysis, drug screening, lipid analysis, and metabolomics. The confidence in MS/MS-based annotation of chemical structures is impacted by instrumental settings and requirements, data acquisition modes including data-dependent and data-independent methods, library scoring algorithms, as well as post-curation steps. We critically discuss parameters that influence search results, such as mass accuracy, precursor ion isolation width, intensity thresholds, centroiding algorithms, and acquisition speed. A range of publicly and commercially available MS/MS databases such as NIST, MassBank, MoNA, LipidBlast, Wiley MSforID, and METLIN are surveyed. In addition, software tools including NIST MS Search, MS-DIAL, Mass Frontier, SmileMS, Mass++, and XCMS2 to perform fast MS/MS search are discussed. MS/MS scoring algorithms and challenges during compound annotation are reviewed. Advanced methods such as the in silico generation of tandem mass spectra using quantum chemistry and machine learning methods are covered. Community efforts for curation and sharing of tandem mass spectra that will allow for faster distribution of scientific discoveries are discussed.
Collapse
Affiliation(s)
- Tobias Kind
- Genome Center, Metabolomics, UC Davis, Davis, California
| | - Hiroshi Tsugawa
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan
| | - Tomas Cajka
- Genome Center, Metabolomics, UC Davis, Davis, California
| | - Yan Ma
- National Institute of Biological Sciences, Beijing, People’s Republic of China
| | - Zijuan Lai
- Genome Center, Metabolomics, UC Davis, Davis, California
| | | | | | | | | | - Masanori Arita
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, Japan
| | - Oliver Fiehn
- Genome Center, Metabolomics, UC Davis, Davis, California
- Faculty of Sciences, Department of Biochemistry, King Abdulaziz University, Jeddah, Saudi Arabia
| |
Collapse
|
13
|
Helfer AG, Michely JA, Weber AA, Meyer MR, Maurer HH. Liquid chromatography-high resolution-tandem mass spectrometry using Orbitrap technology for comprehensive screening to detect drugs and their metabolites in blood plasma. Anal Chim Acta 2017; 965:83-95. [DOI: 10.1016/j.aca.2017.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 02/06/2017] [Accepted: 03/02/2017] [Indexed: 01/30/2023]
|
14
|
|
15
|
LeBlanc LM, Powers SW, Grossert JS, White RL. Competing fragmentation processes of β-substituted propanoate ions upon collision-induced dissociation. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:2133-2144. [PMID: 27476993 DOI: 10.1002/rcm.7699] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/22/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE When subjected to collisional activation, gas-phase carboxylate ions typically undergo decarboxylation. However, alternative fragmentation processes dominate when the carboxylate group is located within certain structural motifs. In this work, the fragmentation processes of β-substituted carboxylate ions are characterized to improve correlations between reactivity and structure. METHODS Mass spectra were collected using both ion trap and triple quadrupole mass spectrometers operating in the negative ion mode; collision-induced dissociation (CID) of ions was used to study the relationship between product ions and the structures of their precursor ions. Quantum mechanical computations were performed on a full range of reaction geometries at the MP2/6-311++G(2d,p)//B3LYP/6-31++G(2d,p) level of theory. RESULTS For a series of β-substituted carboxylate ions, a product ion corresponding to the anion of the β-substituent was obtained upon CID. Detailed computations indicated that decarboxylative elimination and at least one other fragmentation mechanism had feasible energetics for the formation of substituent anions differing in their gas-phase basicities. Predicted energetics for anti- and synperiplanar alignments in the transition structures for decarboxylative elimination correlated with the positions of crossover points in breakdown curves acquired for conformationally constrained ions. CONCLUSIONS The feasibility of more than one mechanism was established for the fragmentation of β-substituted propanoates. The contribution of each mechanistic pathway to the formation of the substituent anion was influenced by structural variations and conformational constraints, but mostly depended on the nature of the substituent. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Luc M LeBlanc
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Sean W Powers
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada, B3H 4R2
| | - J Stuart Grossert
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Robert L White
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, Canada, B3H 4R2.
| |
Collapse
|
16
|
Anilanmert B, Çavuş F, Narin I, Cengiz S, Sertler Ş, Özdemir AA, Açikkol M. Simultaneous analysis method for GHB, ketamine, norketamine, phenobarbital, thiopental, zolpidem, zopiclone and phenytoin in urine, using C18 poroshell column. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1022:230-241. [DOI: 10.1016/j.jchromb.2016.03.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/09/2016] [Accepted: 03/25/2016] [Indexed: 10/22/2022]
|
17
|
Nuñez A, Lehotay SJ, Lightfield AR. Structural characterization of product ions of regulated veterinary drugs by electrospray ionization and quadrupole time-of-flight mass spectrometry. Part 3: Anthelmintics and thyreostats. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:813-822. [PMID: 26969922 DOI: 10.1002/rcm.7508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/22/2015] [Accepted: 01/10/2016] [Indexed: 06/05/2023]
Abstract
RATIONALE Previously, we have reported a liquid chromatography/tandem mass spectrometry method for the identification and quantification of regulated veterinary drugs in food animals. The method uses three selected transition ions per analyte but structural characterization is also needed. This work is a continuation of two previous publications in which we propose structures of the selected transition ions of 130 veterinary drugs altogether. METHODS In this work, 24 additional veterinary drugs were analyzed by infusion into a high-resolution quadrupole time-of-flight (QTOF) mass spectrometer using electrospray ionization (ESI) in positive or negative mode. The TOF analyzer was calibrated to achieve low error mass accuracy in the MS and MS/MS modes. Also, the MS(2) and MS(3) spectra were obtained by using a Q-Trap mass spectrometer to further determine the possible pathways of ion formation. RESULTS The low error mass spectrometry analysis allowed the elucidation of the ion formulae of selected transition ions for qualitative identification. The rational interpretation of data including a review of the published literature led to the proposed structures of the MS/MS product ions of 24 compounds covering two classes of regulated veterinary drugs (anthelmintics and thyreostats). In addition, the use of MS(2) and MS(3) experiments led to the establishment of fragmentation patterns. CONCLUSIONS The identification and quantification of veterinary drug residues is helpful information for regulatory monitoring programs in defense of regulatory enforcement actions. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.
Collapse
Affiliation(s)
- Alberto Nuñez
- US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA, 19038, USA
| | - Steven J Lehotay
- US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA, 19038, USA
| | - Alan R Lightfield
- US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA, 19038, USA
| |
Collapse
|
18
|
Multiple stage MS in analysis of plasma, serum, urine and in vitro samples relevant to clinical and forensic toxicology. Bioanalysis 2016; 8:457-81. [DOI: 10.4155/bio.16.15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This paper reviews MS approaches applied to metabolism studies, structure elucidation and qualitative or quantitative screening of drugs (of abuse) and/or their metabolites. Applications in clinical and forensic toxicology were included using blood plasma or serum, urine, in vitro samples, liquids, solids or plant material. Techniques covered are liquid chromatography coupled to low-resolution and high-resolution multiple stage mass analyzers. Only PubMed listed studies published in English between January 2008 and January 2015 were considered. Approaches are discussed focusing on sample preparation and mass spectral settings. Comments on advantages and limitations of these techniques complete the review.
Collapse
|
19
|
Wright PA, Alex A, Pullen FS. Can computational chemistry be used to predict CID fragmentation of anions? RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:2309-2315. [PMID: 26522325 DOI: 10.1002/rcm.7394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/10/2015] [Accepted: 09/10/2015] [Indexed: 06/05/2023]
Affiliation(s)
| | - Alexander Alex
- Evenor Consulting Ltd, The New Barn, Mill Lane, Eastry, UK
| | | |
Collapse
|
20
|
Helfer AG, Michely JA, Weber AA, Meyer MR, Maurer HH. Orbitrap technology for comprehensive metabolite-based liquid chromatographic–high resolution-tandem mass spectrometric urine drug screening – Exemplified for cardiovascular drugs. Anal Chim Acta 2015; 891:221-33. [DOI: 10.1016/j.aca.2015.08.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 07/20/2015] [Accepted: 08/08/2015] [Indexed: 10/23/2022]
|
21
|
|
22
|
Brycht M, Burnat B, Skrzypek S, Guzsvány V, Gutowska N, Robak J, Nosal–Wiercińska A. Voltammetric and corrosion studies of the fungicide fludioxonil. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.01.130] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
23
|
Shah I, Petroczi A, Uvacsek M, Ránky M, Naughton DP. Hair-based rapid analyses for multiple drugs in forensics and doping: application of dynamic multiple reaction monitoring with LC-MS/MS. Chem Cent J 2014; 8:73. [PMID: 25530799 PMCID: PMC4272537 DOI: 10.1186/s13065-014-0073-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 11/26/2014] [Indexed: 11/10/2022] Open
Abstract
Background Considerable efforts are being extended to develop more effective methods to detect drugs in forensic science for applications such as preventing doping in sport. The aim of this study was to develop a sensitive and accurate method for analytes of forensic and toxicological nature in human hair at sub-pg levels. Results The hair test covers a range of different classes of drugs and metabolites of forensic and toxicological nature including selected anabolic steroids, cocaine, amphetamines, cannabinoids, opiates, bronchodilators, phencyclidine and ketamine. For extraction purposes, the hair samples were decontaminated using dichloromethane, ground and treated with 1 M sodium hydroxide and neutralised with hydrochloric acid and phosphate buffer and the homogenate was later extracted with hexane using liquid-liquid extraction (LLE). Following extraction from hair samples, drug-screening employed liquid chromatography coupled to tandem mass spectrometric (LC-MS/MS) analysis using dynamic multiple reaction monitoring (DYN-MRM) method using proprietary software. The screening method (for > 200 drugs/metabolites) was calibrated with a tailored drug mixture and was validated for 20 selected drugs for this study. Using standard additions to hair sample extracts, validation was in line with FDA guidance. A Zorbax Eclipse plus C18 (2.1 mm internal diameter × 100 mm length × 1.8 μm particle size) column was used for analysis. Total instrument run time was 8 minutes with no noted matrix interferences. The LOD of compounds ranged between 0.05-0.5 pg/mg of hair. 233 human hair samples were screened using this new method and samples were confirmed positive for 20 different drugs, mainly steroids and drugs of abuse. Conclusions This is the first report of the application of this proprietary system to investigate the presence of drugs in human hair samples. The method is selective, sensitive and robust for the screening and confirmation of multiple drugs in a single analysis and has potential as a very useful tool for the analysis of large array of controlled substances and drugs of abuse.
Collapse
Affiliation(s)
- Iltaf Shah
- School of Life Sciences, Kingston University, Kingston-upon-Thames, Surrey, UK
| | - Andrea Petroczi
- School of Life Sciences, Kingston University, Kingston-upon-Thames, Surrey, UK
| | - Martina Uvacsek
- Faculty of Physical Education and Sports Sciences, Semmelweis University, Budapest, Hungary
| | - Márta Ránky
- Eötvös Lóránd University, Faculty of Education and Psychology, Budapest, Hungary
| | - Declan P Naughton
- School of Life Sciences, Kingston University, Kingston-upon-Thames, Surrey, UK
| |
Collapse
|
24
|
Eremin DB, Ananikov VP. Exceptional Behavior of Ni2O2 Species Revealed by ESI-MS and MS/MS Studies in Solution. Application of Superatomic Core To Facilitate New Chemical Transformations. Organometallics 2014. [DOI: 10.1021/om500637k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Dmitry B. Eremin
- Zelinsky
Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Pr. 47, Moscow 119991, Russia
| | - Valentine P. Ananikov
- Zelinsky
Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Pr. 47, Moscow 119991, Russia
- Department
of Chemistry, Saint Petersburg State University, Stary Petergof, 198504, Russia
| |
Collapse
|
25
|
Guo M, Pan Y, Zhang R, Cao Y, Chen J, Pan Y. The specific cleavage of lactone linkage to open-loop in cyclic lipopeptide during negative ESI tandem mass spectrometry: the hydrogen bond interaction effect of 4-ethyl guaiacol. PLoS One 2014; 9:e104835. [PMID: 25144459 PMCID: PMC4140680 DOI: 10.1371/journal.pone.0104835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 07/13/2014] [Indexed: 11/27/2022] Open
Abstract
Mass spectrometry is a valuable tool for the analysis and identification of chemical compounds, particularly proteins and peptides. Lichenysins G, the major cyclic lipopeptide of lichenysin, and the non-covalent complex of lichenysins G and 4-ethylguaiacol were investigated with negative ion ESI tandem mass spectrometry. The different fragmentation mechanisms for these compounds were investigated. Our study shows the 4-ethylguaiacol hydrogen bond with the carbonyl oxygen of the ester group in the loop of lichenysins G. With the help of this hydrogen bond interaction, the ring structure preferentially opens in lactone linkage rather than O-C bond of the ester-group to produce alcohol and ketene. Isothermal titration 1H-NMR analysis verified the hydrogen bond and determined the proportion of subject and ligand in the non-covalent complex to be 1∶1. Theoretical calculations also suggest that the addition of the ligand can affect the energy of the transition structures (TS) during loop opening.
Collapse
Affiliation(s)
- Mengzhe Guo
- Department of Chemistry, Zhejiang University, Hangzhou, China
| | - Youlu Pan
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Rong Zhang
- School of Biotechnology, Jiangnan University, Wuxi, China
| | - Yang Cao
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jianzhong Chen
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yuanjiang Pan
- Department of Chemistry, Zhejiang University, Hangzhou, China
| |
Collapse
|
26
|
Gillis EAL, Grossert JS, White RL. Rearrangements leading to fragmentations of hydrocinnamate and analogous nitrogen-containing anions upon collision-induced dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:388-397. [PMID: 24408178 DOI: 10.1007/s13361-013-0788-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/14/2013] [Accepted: 11/18/2013] [Indexed: 06/03/2023]
Abstract
Tandem mass spectrometry (MS/MS) confirmed decarboxylation as the major collision-induced dissociation (CID) pathway of deprotonated hydrocinnamic acid (C6H5CH2CH2CO2H), N-phenylglycine (C6H5NHCH2CO2H) and 3-pyridin-2-ylpropanoic acid (C5H4NCH2CH2CO2H). The structure and stability of isomeric precursor and product anions were examined using density functional theory and ab initio methods. Geometry optimizations and frequency calculations were performed using the B3LYP/6-31++G(2d,p) level of theory and basis set with additional single point energies calculated at the MP2/6-311++G(2d,p) level. The formation of a delocalized product anion by carboxyl group-mediated migration of a benzylic proton to the ortho position of the ring and subsequent Cα-CO2(-) bond cleavage was energetically more favorable than direct decarboxylation and rearrangements of anions within ion-neutral complexes with carbon dioxide. The energy barrier for rearrangement of the delocalized product anion to the more stable benzylic anion was lowest in the fragmentation pathway of 3-pyridin-2-ylpropanoate. More energetically demanding fragmentation processes were indicated by the formation of other product anions at higher collision energy. Computations supported the feasibility of the formation of hydroxycarbonyl, styrene, and phenide ions from the benzylic anion of hydrocinnamate and the corresponding product anions from the nitrogen-containing analogues. The loss of dihydrogen from decarboxylated 3-pyridin-2-ylpropanoate was characterized computationally as hydride abstraction of an aryl proton. Overall, the results highlight the importance of exploring rearrangements in the fragmentation pathways of ions formed by electrospray ionization (ESI).
Collapse
Affiliation(s)
- Elizabeth A L Gillis
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada
| | | | | |
Collapse
|
27
|
Critical practical aspects in the application of liquid chromatography–mass spectrometric studies for the characterization of impurities and degradation products. J Pharm Biomed Anal 2014; 87:191-217. [DOI: 10.1016/j.jpba.2013.04.027] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 04/18/2013] [Indexed: 11/18/2022]
|
28
|
D'Agostino LA, Mabury SA. Identification of novel fluorinated surfactants in aqueous film forming foams and commercial surfactant concentrates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:121-9. [PMID: 24256061 DOI: 10.1021/es403729e] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Recent studies comparing the results of total organofluorine-combustion ion chromatography (TOF-CIC) to targeted analysis of perfluoroalkyl and polyfluoroalkyl substances (PFASs) by liquid chromatography tandem mass spectrometry (LC-MS/MS) have shown that a significant yet variable portion of the total organofluorine in environmental and biological samples is in the form of unknown PFASs. A portion of this unknown organofluorine likely originates in proprietary fluorinated surfactants not included in LC-MS/MS analyses and not fully characterized by the environmental science community, which may enter the environment through use in aqueous film forming foams (AFFFs) for firefighting. Contamination of water, biota, and soils with various PFASs due to AFFF deployment has been documented. Ten fluorinated AFFF concentrates, 9 of which were obtained from fire sites in Ontario, Canada, and two commercial fluorinated surfactant concentrates were characterized in order to identify novel fluorinated surfactants. Mixed-mode ion exchange solid phase extraction (SPE) fractionated fluorinated surfactants based on ionic character. High resolution mass spectrometry assigned molecular formulas to fluorinated surfactant ions, while collision induced dissociation (CID) spectra assisted structural elucidation. LC-MS/MS detected isomers and low abundance fluorinated chain lengths. In total, 12 novel and 10 infrequently reported PFAS classes were identified in fluorinated chain lengths from C3 to C15 for a total of 103 compounds. Further research should examine the environmental fate and toxicology of these PFASs, especially their potential as perfluoroalkyl acid (PFAA) precursors.
Collapse
Affiliation(s)
- Lisa A D'Agostino
- Department of Chemistry, University of Toronto , 80 St George Street, Toronto, M5S 3H6 Ontario, Canada
| | | |
Collapse
|
29
|
Hilger RT, Santini RE, McLuckey SA. Nondestructive Tandem Mass Spectrometry Using a Linear Quadrupole Ion Trap Coupled to a Linear Electrostatic Ion Trap. Anal Chem 2013; 85:5226-32. [PMID: 23593952 DOI: 10.1021/ac4007182] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Ryan T. Hilger
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084,
United States
| | - Robert E. Santini
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084,
United States
| | - Scott A. McLuckey
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084,
United States
| |
Collapse
|
30
|
Borràs S, Kaufmann A, Companyó R. Correlation of precursor and product ions in single-stage high resolution mass spectrometry. A tool for detecting diagnostic ions and improving the precursor elemental composition elucidation. Anal Chim Acta 2013; 772:47-58. [DOI: 10.1016/j.aca.2013.02.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 01/30/2013] [Accepted: 02/08/2013] [Indexed: 10/27/2022]
|
31
|
Chakraborty S, Gruber T, Barry CE, Boshoff HI, Rhee KY. Para-aminosalicylic acid acts as an alternative substrate of folate metabolism in Mycobacterium tuberculosis. Science 2013; 339:88-91. [PMID: 23118010 PMCID: PMC3792487 DOI: 10.1126/science.1228980] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Folate biosynthesis is an established anti-infective target, and the antifolate para-aminosalicylic acid (PAS) was one of the first anti-infectives introduced into clinical practice on the basis of target-based drug discovery. Fifty years later, PAS continues to be used to treat tuberculosis. PAS is assumed to inhibit dihydropteroate synthase (DHPS) in Mycobacterium tuberculosis by mimicking the substrate p-aminobenzoate (PABA). However, we found that sulfonamide inhibitors of DHPS inhibited growth of M. tuberculosis only weakly because of their intracellular metabolism. In contrast, PAS served as a replacement substrate for DHPS. Products of PAS metabolism at this and subsequent steps in folate metabolism inhibited those enzymes, competing with their substrates. PAS is thus a prodrug that blocks growth of M. tuberculosis when its active forms are generated by enzymes in the pathway they poison.
Collapse
Affiliation(s)
- Sumit Chakraborty
- Department of Medicine, Weill Cornell Medical College, NY, NY, USA
- Department of Microbiology & Immunology , Weill Cornell Medical College, NY, NY, USA
| | - Todd Gruber
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Clifton E. Barry
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Helena I. Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Kyu Y. Rhee
- Department of Medicine, Weill Cornell Medical College, NY, NY, USA
- Department of Microbiology & Immunology , Weill Cornell Medical College, NY, NY, USA
| |
Collapse
|