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Rutz A, Wolfender JL. Automated Composition Assessment of Natural Extracts: Untargeted Mass Spectrometry-Based Metabolite Profiling Integrating Semiquantitative Detection. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:18010-18023. [PMID: 37949451 PMCID: PMC10683005 DOI: 10.1021/acs.jafc.3c03099] [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: 05/12/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 11/12/2023]
Abstract
Recent developments in mass spectrometry-based metabolite profiling allow unprecedented qualitative coverage of complex biological extract composition. However, the electrospray ionization used in metabolite profiling generates multiple artifactual signals for a single analyte. This leads to thousands of signals per analysis without satisfactory means of filtering those corresponding to abundant constituents. Generic approaches are therefore needed for the qualitative and quantitative annotation of a broad range of relevant constituents. For this, we used an analytical platform combining liquid chromatography-mass spectrometry (LC-MS) with Charged Aerosol Detection (CAD). We established a generic metabolite profiling for the concomitant recording of qualitative MS data and semiquantitative CAD profiles. The MS features (recorded in high-resolution tandem MS) are grouped and annotated using state-of-the-art tools. To efficiently attribute features to their corresponding extracted and integrated CAD peaks, a custom signal pretreatment and peak-shape comparison workflow is built. This strategy allows us to automatically contextualize features at both major and minor metabolome levels, together with a detailed reporting of their annotation including relevant orthogonal information (taxonomy, retention time). Signals not attributed to CAD peaks are considered minor metabolites. Results are illustrated on an ethanolic extract of Swertia chirayita (Roxb.) H. Karst., a bitter plant of industrial interest, exhibiting the typical complexity of plant extracts as a proof of concept. This generic qualitative and quantitative approach paves the way to automatically assess the composition of single natural extracts of interest or broader collections, thus facilitating new ingredient registrations or natural-extracts-based drug discovery campaigns.
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Affiliation(s)
- Adriano Rutz
- School
of Pharmaceutical Sciences, University of
Geneva, 1211 Geneva, Switzerland
- Institute
of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1211 Geneva, Switzerland
- Institute
of Molecular Systems Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Jean-Luc Wolfender
- School
of Pharmaceutical Sciences, University of
Geneva, 1211 Geneva, Switzerland
- Institute
of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1211 Geneva, Switzerland
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2
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Simon C, Dührkop K, Petras D, Roth VN, Böcker S, Dorrestein PC, Gleixner G. Mass Difference Matching Unfolds Hidden Molecular Structures of Dissolved Organic Matter. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11027-11040. [PMID: 35834352 PMCID: PMC9352317 DOI: 10.1021/acs.est.2c01332] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/20/2022] [Accepted: 06/30/2022] [Indexed: 05/30/2023]
Abstract
Ultrahigh-resolution Fourier transform mass spectrometry (FTMS) has revealed unprecedented details of natural complex mixtures such as dissolved organic matter (DOM) on a molecular formula level, but we lack approaches to access the underlying structural complexity. We here explore the hypothesis that every DOM precursor ion is potentially linked with all emerging product ions in FTMS2 experiments. The resulting mass difference (Δm) matrix is deconvoluted to isolate individual precursor ion Δm profiles and matched with structural information, which was derived from 42 Δm features from 14 in-house reference compounds and a global set of 11 477 Δm features with assigned structure specificities, using a dataset of ∼18 000 unique structures. We show that Δm matching is highly sensitive in predicting potential precursor ion identities in terms of molecular and structural composition. Additionally, the approach identified unresolved precursor ions and missing elements in molecular formula annotation (P, Cl, F). Our study provides first results on how Δm matching refines structural annotations in van Krevelen space but simultaneously demonstrates the wide overlap between potential structural classes. We show that this effect is likely driven by chemodiversity and offers an explanation for the observed ubiquitous presence of molecules in the center of the van Krevelen space. Our promising first results suggest that Δm matching can both unfold the structural information encrypted in DOM and assess the quality of FTMS-derived molecular formulas of complex mixtures in general.
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Affiliation(s)
- Carsten Simon
- Molecular
Biogeochemistry, Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745 Jena, Germany
| | - Kai Dührkop
- Chair
for Bioinformatics, Faculty of Mathematics and Computer Science, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, 07743 Jena, Germany
| | - Daniel Petras
- Collaborative
Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and
Pharmaceutical Sciences, University of California
San Diego, 9500 Gilman Drive, MC 0657, La Jolla, California 92093-0657, United States of America
- CMFI
Cluster of Excellence, Interfaculty Institute of Microbiology and
Medicine, University of Tübingen, Auf der Morgenstelle 24, 72076 Tübingen, Germany
| | - Vanessa-Nina Roth
- Molecular
Biogeochemistry, Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745 Jena, Germany
| | - Sebastian Böcker
- Chair
for Bioinformatics, Faculty of Mathematics and Computer Science, Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, 07743 Jena, Germany
| | - Pieter C. Dorrestein
- Collaborative
Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and
Pharmaceutical Sciences, University of California
San Diego, 9500 Gilman Drive, MC 0657, La Jolla, California 92093-0657, United States of America
| | - Gerd Gleixner
- Molecular
Biogeochemistry, Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, Hans-Knöll-Straße 10, 07745 Jena, Germany
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Bahureksa W, Tfaily MM, Boiteau RM, Young RB, Logan MN, McKenna AM, Borch T. Soil Organic Matter Characterization by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR MS): A Critical Review of Sample Preparation, Analysis, and Data Interpretation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9637-9656. [PMID: 34232025 DOI: 10.1021/acs.est.1c01135] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The biogeochemical cycling of soil organic matter (SOM) plays a central role in regulating soil health, water quality, carbon storage, and greenhouse gas emissions. Thus, many studies have been conducted to reveal how anthropogenic and climate variables affect carbon sequestration and nutrient cycling. Among the analytical techniques used to better understand the speciation and transformation of SOM, Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) is the only technique that has sufficient mass resolving power to separate and accurately assign elemental compositions to individual SOM molecules. The global increase in the application of FTICR MS to address SOM complexity has highlighted the many challenges and opportunities associated with SOM sample preparation, FTICR MS analysis, and mass spectral interpretation. Here, we provide a critical review of recent strategies for SOM characterization by FTICR MS with emphasis on SOM sample collection, preparation, analysis, and data interpretation. Data processing and visualization methods are presented with suggested workflows that detail the considerations needed for the application of molecular information derived from FTICR MS. Finally, we highlight current research gaps, biases, and future directions needed to improve our understanding of organic matter chemistry and cycling within terrestrial ecosystems.
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Affiliation(s)
- William Bahureksa
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Malak M Tfaily
- Department of Environmental Science, University of Arizona, Tucson, Arizona 85721, United States
| | - Rene M Boiteau
- College of Earth, Ocean, Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331, United States
| | - Robert B Young
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80523-1170, United States
| | - Merritt N Logan
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Amy M McKenna
- National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Dr., Tallahassee, Florida 32310-4005, United States
| | - Thomas Borch
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80523-1170, United States
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Patriarca C, Hawkes JA. High Molecular Weight Spectral Interferences in Mass Spectra of Dissolved Organic Matter. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:394-397. [PMID: 33232162 PMCID: PMC7791554 DOI: 10.1021/jasms.0c00353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this paper we investigate interferences that appear in molecular mass spectra from aquatic samples. The interferences are identified as doubly charged ions originating from high molecular weight material, which is especially abundant in terrestrial samples. The interferences could be incorrectly assigned to singly charged formulas with high aromaticity and heteroatom content, as the mass error from such formulas can be less than 1 ppm. We propose a strategy for filtering the interference peaks from mass lists based on the presence of their equivalent isotopologue peaks at mass defects of ∼0.5 Da.
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Hawkes JA, Sjöberg PJR, Bergquist J, Tranvik LJ. Complexity of dissolved organic matter in the molecular size dimension: insights from coupled size exclusion chromatography electrospray ionisation mass spectrometry. Faraday Discuss 2020; 218:52-71. [PMID: 31120465 DOI: 10.1039/c8fd00222c] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper investigates the relationship between apparent size distribution and molecular complexity of dissolved organic matter from the natural environment. We used a high pressure size exclusion chromatography (HPSEC) method coupled to UV-Vis diode array detection (UV-DAD) and electrospray ionisation mass spectrometry (ESI-MS) in order to compare the apparent size of natural organic matter, determined by HPSEC-UV and the molecular mass determined online by ESI-MS. We found that there was a clear discrepancy between the two methods, and found evidence for an important pool of organic matter that has a strong UV absorbance and no ESI-MS signal. Contrary to some previous research, we found no evidence that apparently high molecular weight organic matter is constituted by aggregates of low molecular weight (<1000 Da) material. Furthermore, our results suggest that the majority of apparent size variability within the ESI ionisable pool of organic matter is due to secondary interaction and exclusion effects on the HPSEC column, and not true differences in hydrodynamic size or intermolecular aggregation.
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Affiliation(s)
- J A Hawkes
- Analytical Chemistry, Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden.
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Prasannan CB, Mishra V, Jaiswal D, Wangikar PP. Mass Isotopologue Distribution of dimer ion adducts of intracellular metabolites for potential applications in 13C Metabolic Flux Analysis. PLoS One 2019; 14:e0220412. [PMID: 31433815 PMCID: PMC6703694 DOI: 10.1371/journal.pone.0220412] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/15/2019] [Indexed: 01/30/2023] Open
Abstract
13C Metabolic Flux Analysis (13C-MFA) is a powerful tool for quantification of carbon flux distribution in metabolic pathways. However, the requirement to obtain accurate labeling patterns, especially for compounds with low abundance, poses a challenge. Chromatographic separation and high sensitivity of the modern mass spectrometers (MS) alleviate this problem to a certain extent. However, the presence of derivatives such as in-source fragments, multimer ion adducts, and multiply charged ions result in reduced intensity of the molecular ion. While multimer ion adducts have been reported in the field of metabolomics, their presence is considered undesirable in quantitative studies. Here, we demonstrate a novel application of dimer ion adducts in calculating the mass isotopologue distribution (MIDs) of the corresponding monomer ions for public domain and in-house generated datasets comprising of 13C-labeling time-course experiments. Out of the 100 standard compounds analyzed, we could detect multimer ion adducts in 24 of the intermediate metabolites. Further, a subset of these multimer ions were detected in all the biological samples analyzed. Majority of these ion adducts were either not detected in the original study or labeled as a putative features. Regression analysis was performed to estimate the monomer MIDs from those of the dimer. This resulted in accurate estimation regardless of the biological system, chromatographic method, the MS hardware, or the relative abundance of the dimer ion. We argue that this analysis may be useful in cases where satisfactory data cannot be extracted from the chromatographic peaks of the monomer ions.
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Affiliation(s)
- Charulata B. Prasannan
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Vivek Mishra
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Damini Jaiswal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Pramod P. Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, India
- Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
- * E-mail:
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Comparing the Spectroscopic and Molecular Characteristics of Different Dissolved Organic Matter Fractions Isolated by Hydrophobic and Anionic Exchange Resins Using Fluorescence Spectroscopy and FT-ICR-MS. WATER 2017. [DOI: 10.3390/w9080555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Despite the environmental significance of dissolved organic matter (DOM), characterizing DOM is still challenging due to its structural complexity and heterogeneity. In this study, three different chemical fractions, including hydrophobic acid (HPOA), transphilic acid (TPIA), and hydrophilic neutral and base (HPIN/B) fractions, were separated from bulk aquatic DOM samples, and their spectral features and the chemical composition at the molecular level were compared using both fluorescence excitation emission matrix-parallel factor analysis (EEM-PARAFAC) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The HPIN/B fraction was distinguished from the two acidic fractions (i.e., HPOA and TPIA) by the EEM-PARAFAC, while the TPIA fraction was discriminated by using the molecular parameters derived from the FT-ICR MS analyses. Statistical comparison suggests that the spectral dissimilarity among the three chemical fractions might result from the acido-basic properties of DOM samples, while the differences in molecular composition were more likely to be affected by the hydrophobicity of the DOM fractions. The non-metric multidimensional scaling map further revealed that the HPOA was the most heterogeneous among the three fractions. The number of overlapping formulas among the three chemical fractions constituted only <5% of all identified formulas, and those between two different fractions ranged from 2.0% to 24.1%, implying relatively homogeneous properties of the individual chemical fractions with respect to molecular composition. Although employing chemical fractionation achieved a lowering of the DOM heterogeneity, prevalent signatures of either acido-basic property or the hydrophobic nature of DOM on the characteristics of three chemical isolated fractions were not found for this study.
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Raeke J, Lechtenfeld OJ, Wagner M, Herzsprung P, Reemtsma T. Selectivity of solid phase extraction of freshwater dissolved organic matter and its effect on ultrahigh resolution mass spectra. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2016; 18:918-927. [PMID: 27363664 DOI: 10.1039/c6em00200e] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Solid phase extraction (SPE) is often used for enrichment and clean-up prior to analysis of dissolved organic matter (DOM) by electrospray ionization (ESI) coupled to ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). It is generally accepted that extraction by SPE is not quantitative with respect to carbon concentration. However, little information is available on the selectivity of different SPE sorbents and the resulting effect for the acquired DOM mass spectra. Freshwater samples were extracted by the widely used PPL, HLB and C18 sorbents and the molecular composition and size distribution of the DOM in the extracts and in the permeates was compared to the original sample. Dissolved organic carbon (DOC) recoveries ranged between 20% and 65% for the three tested SPE sorbents. Size-exclusion chromatography coupled to organic carbon detection (SEC-OCD) revealed that limited recovery by PPL and HLB was primarily due to incomplete elution of a fraction of apparent high molecular weight from the solid phase. In contrast, incomplete retention on the solid phase, mainly observed for the C18 cartridge, was attributed to a fraction of low molecular weight. The FT-ICR mass spectra of the original sample and the SPE extracts did not differ significantly in their molecular weight distribution, but they showed sorbent specific differences in the degree of oxygenation and saturation. We concluded that the selective enrichment of freshwater DOM by SPE is less critical for subsequent FT-ICR MS analysis, because those fractions that are not sufficiently recovered have comparatively small effects on the mass spectra. This was confirmed by the extraction of model compounds, showing that very polar and small molecules are poorly extracted, but also have a low response in ESI-MS. Of the three tested SPE cartridges the PPL material offered the best properties for DOM enrichment for subsequent FT-ICR MS analysis as it minimizes too strong and too weak DOM-sorbent interactions.
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Affiliation(s)
- Julia Raeke
- Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany.
| | - Oliver J Lechtenfeld
- Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany. and Helmholtz Centre for Environmental Research - UFZ, ProVIS - Centre for Chemical Microscopy, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Martin Wagner
- TZW: DVGW Water Technology Center, Wasserwerkstrasse 2, 01326 Dresden, Germany
| | - Peter Herzsprung
- Helmholtz Centre for Environmental Research - UFZ, Department of Lake Research, Brueckstrasse 3a, 39114 Magdeburg, Germany
| | - Thorsten Reemtsma
- Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany.
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Harris BD, Brown TA, McGehee JL, Houserova D, Jackson BA, Buchel BC, Krajewski LC, Whelton AJ, Stenson AC. Characterization of Disinfection By-Products from Chromatographically Isolated NOM through High-Resolution Mass Spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:14239-14248. [PMID: 26554276 DOI: 10.1021/acs.est.5b03466] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
As levels of natural organic matter (NOM) in surface water rise, the minimization of potentially harmful disinfection by-products (DBPs) becomes increasingly critical. Here, we introduce the advantage that chromatographic prefractionation brings to investigating compositional changes to NOM caused by chlorination. Fractionation reduces complexity, making it easier to observe changes and attribute them to specific components. Under the conditions tested (0.1-0.4 g of Cl to g of C without further additives), the differences between highly and less oxidized NOM were striking. Highly oxidized NOM formed more diverse Cl-containing DPB, had a higher propensity to react with multiple Cl, and tended to transform so drastically as to no longer be amenable to electrospray-ionization mass spectral detection. Less-oxidized material tended to incorporate one Cl and retain its humiclike composition. N-containing, lipidlike, and condensed aromatic structure (CAS)-like NOM were selectively enriched in mass spectra, suggesting that such components do not react as extensively with NaOCl as their counterparts. Carbohydrate-like NOM, conversely, was selectively removed from spectra by chlorination.
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Affiliation(s)
| | | | | | | | | | | | - Logan C Krajewski
- Department of Chemistry and Biochemistry, Florida State University , Tallahassee, Florida 32306, United States
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Roberts NB, Curtis SA, Milan AM, Ranganath LR. The Pigment in Alkaptonuria Relationship to Melanin and Other Coloured Substances: A Review of Metabolism, Composition and Chemical Analysis. JIMD Rep 2015; 24:51-66. [PMID: 26093627 DOI: 10.1007/8904_2015_453] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 01/02/2023] Open
Abstract
The pigments found in plants, animals and humic substances are well described and classified. In humans considerable progress has been made with the main pigment melanin in defining its biochemistry, the different types and function. However, analytical techniques to show these differences in vivo are still not readily available. NMR and IR spectroscopy are relatively insensitive and reveal only major structural differences. Techniques utilising MS are useful in determining elemental content but require further studies to optimise conditions for accurate mass analysis. How the components may be structurally organised seems to be the most problematic with scanning TEM and the improved FTIR of use in this respect. As regards understanding the nature of the pigment related to HGA seen in patients with Alkaptonuria (AKU), it is still thought of as a melaninlike pigment simply because of its colour and likewise thought to be a polymer of undetermined size. It is important that detailed analysis be carried out to define more accurately this pigment. However, observations suggest it to be the same as the HGA-derived pigment, pyomelanin, produced by bacteria and containing both quinone and phenolic groups. The interesting developments in alkaptonuria will be to understand how such a polymer can cause such profound collagen and connective tissue damage and how best to reverse this process.
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Affiliation(s)
- N B Roberts
- Department of Clinical Biochemistry and Metabolic Medicine, The Royal Liverpool and Broadgreen University Hospitals Trust, Liverpool, L7 8XP, UK.
| | - S A Curtis
- Department of Clinical Biochemistry and Metabolic Medicine, The Royal Liverpool and Broadgreen University Hospitals Trust, Liverpool, L7 8XP, UK
| | - A M Milan
- Department of Clinical Biochemistry and Metabolic Medicine, The Royal Liverpool and Broadgreen University Hospitals Trust, Liverpool, L7 8XP, UK
| | - L R Ranganath
- Department of Clinical Biochemistry and Metabolic Medicine, The Royal Liverpool and Broadgreen University Hospitals Trust, Liverpool, L7 8XP, UK
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