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Ün İ, Ün ŞŞ, Tanrıkulu N, Ünlü A, Ok S. Assessing the concentration of conjugated fatty acids within pomegranate seed oil using quantitative nuclear magnetic resonance (qNMR). PHYTOCHEMICAL ANALYSIS : PCA 2022; 33:452-459. [PMID: 34888963 DOI: 10.1002/pca.3101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
INTRODUCTION Pomegranate seed is rich in oil, and seed oil of pomegranate consists of conjugated fatty acids with different percentages. OBJECTIVES The current contribution covers how to determine percentages of different isomeric conjugated fatty acids. METHODS The percentages of these isomers are analysed by quantitative nuclear magnetic resonance (qNMR) using benzoic acid as an internal reference chemical with a well-defined amount. Linear mathematical equations are developed for the quantitative analysis of fatty acids found in pomegranate seed oil. RESULTS The developed approach is utilised for the pomegranate seed oils prepared in the laboratory and tested for commercial samples. Among the oils derived at the laboratory, the Yeni Hicaz pomegranate cultivar seeds yielded the highest fraction of punicic acid. Among the acids, punicic acid was the one with the highest fraction, while linolenic acid was the one with the lowest percentage. CONCLUSIONS These results are important in identifying pomegranate seed oils. Among the commercial samples tested with the current approach, only one of them showed similar content analysis as in the laboratory-derived oils.
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Affiliation(s)
- İlker Ün
- TUBITAK UME, Chemistry Group Laboratories, Gebze, Kocaeli, Turkey
| | - Şule Şahin Ün
- Faculty of Science, Department of Chemistry, Gebze Technical University, Gebze, Kocaeli, Turkey
| | - Nazim Tanrıkulu
- Balikesir Municipality Farmer Education Centre, Burhaniye, Balıkesir, Turkey
| | - Aişe Ünlü
- Faculty of Science, Department of Chemistry, Gebze Technical University, Gebze, Kocaeli, Turkey
| | - Salim Ok
- Petroleum Research Centre, Kuwait Institute for Scientific Research, Safat, Kuwait
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2
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Trifiró G, York R, Bell NGA. High-Resolution Molecular-Level Characterization of a Blanket Bog Peat Profile. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:660-671. [PMID: 34932324 DOI: 10.1021/acs.est.1c05837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
To understand peatland carbon-cycling processes ultimately requires the ability to track changes occurring on the molecular-level. In this study, we profile a peat core taken from the world's largest blanket bog, Flow Country, Scotland, using physicochemical properties, ATR-FTIR, solid/liquid-state NMR, and solid/liquid-state FT-ICR-MS. Air-dried peat and labile and recalcitrant peat extracts, including pore water dissolved organic matter (PW-DOM), are analyzed and the merits of each technique are discussed. Solid-state NMR demonstrated changing distribution of compound classes with core depth and water table, the latter not picked up by IR. Liquid-state NMR and MS both demonstrated variations in molecular composition along the core depth in all phases and extracts. Contrary to previous reports, the composition of PW-DOM varied with depth. Major compounds, some previously unreported, identified by 1D/2D NMR occurred throughout the core, suggesting the existence of hot spots of microbial activity/compound accumulation. Offering complementary views, the techniques provided evidence of gradual molecular level changes with age, zonation due to the water table, and hot spots due to microbial activity. This study provides new insights into the molecular signatures of peat layers and establishes the foundation for examining peat function and health at the molecular-level.
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Affiliation(s)
- Gianluca Trifiró
- University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Richard York
- University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
| | - Nicholle G A Bell
- University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, United Kingdom
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Baishya B, Verma A, Parihar R. Accelerated 13C detection by concentrating the NMR sample in a biphasic solvent system. Analyst 2021; 146:6582-6591. [PMID: 34586127 DOI: 10.1039/d1an00470k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CDCl3 is the most frequently used solvent for the NMR investigation of organic compounds. Busy chemistry labs need to investigate hundreds of compounds daily. While 1H NMR investigation takes a couple of minutes, recording 13C NMR spectra necessitates hours of signal averaging due to the low abundance and low sensitivity of 13C nuclei. The longer acquisition time for 13C NMR results in a loss of precious spectrometer time in a shared multi-user environment. A regular 5 mm o.d. NMR tube is the most commonly used tube for NMR in organic chemistry labs and is also the cheapest option. We show that for analytes soluble in the CDCl3 solvent using a regular 5 mm o.d. NMR tube, the speed of 13C observation can be enhanced by a factor of two by resorting to a sample preparation method that employs a biphasic system made of H2O or D2O at the top of another layer of CDCl3. By using the biphasic system of two immiscible solvents, the analyte can be concentrated in the CDCl3 layer (within the more sensitive volume of the NMR coil), resulting in the improvement of the signal to noise ratio (SNR) by a factor of up to 1.8 for 13C and 2D 1H-13C HSQC spectra, which results in more than two-fold reduction in the experimental time. 1H NMR and other 2D NMR also get a sensitivity boost. The amount of CDCl3 required for sample preparation can also be reduced by 40% using this biphasic system (CDCl3/H2O). Sample preparation in such an immiscible biphasic system is effortless and straightforward. The performance of such biphasic samples is closer to that of Shigemi tubes and better than that of 3 mm o.d. tubes.
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Affiliation(s)
- Bikash Baishya
- Centre of Biomedical Research (Formerly Centre of Biomedical Magnetic Resonance), SGPGIMS Campus, Raebareli Road, Lucknow, 226014, India.
| | - Ajay Verma
- Govt. Degree College, Tyuni, 248199, Dehradun, Uttarakhand, India
| | - Rashmi Parihar
- Centre of Biomedical Research (Formerly Centre of Biomedical Magnetic Resonance), SGPGIMS Campus, Raebareli Road, Lucknow, 226014, India. .,Department of Bioinformatics, Dr A. P. J. Abdul Kalam Technical University, Lucknow-226021, U.P., India
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Crook AA, Powers R. Quantitative NMR-Based Biomedical Metabolomics: Current Status and Applications. Molecules 2020; 25:E5128. [PMID: 33158172 PMCID: PMC7662776 DOI: 10.3390/molecules25215128] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/26/2020] [Accepted: 10/30/2020] [Indexed: 12/19/2022] Open
Abstract
Nuclear Magnetic Resonance (NMR) spectroscopy is a quantitative analytical tool commonly utilized for metabolomics analysis. Quantitative NMR (qNMR) is a field of NMR spectroscopy dedicated to the measurement of analytes through signal intensity and its linear relationship with analyte concentration. Metabolomics-based NMR exploits this quantitative relationship to identify and measure biomarkers within complex biological samples such as serum, plasma, and urine. In this review of quantitative NMR-based metabolomics, the advancements and limitations of current techniques for metabolite quantification will be evaluated as well as the applications of qNMR in biomedical metabolomics. While qNMR is limited by sensitivity and dynamic range, the simple method development, minimal sample derivatization, and the simultaneous qualitative and quantitative information provide a unique landscape for biomedical metabolomics, which is not available to other techniques. Furthermore, the non-destructive nature of NMR-based metabolomics allows for multidimensional analysis of biomarkers that facilitates unambiguous assignment and quantification of metabolites in complex biofluids.
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Affiliation(s)
- Alexandra A. Crook
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA
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Ewanicki J, Kim W, Wang W. 2 H SOLCOR: A novel tool for reducing volume variation as a source of error in external standard quantitative NMR. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2020; 58:733-744. [PMID: 32297372 DOI: 10.1002/mrc.5027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Tube to tube volume difference presents a challenge in obtaining correct external standard quantitative NMR (esqNMR) results. Deuterium (2 H) NMR is easily observable, intrinsically quantitative, present in all samples, free of interfering signals, and insensitive to probe tune/match and sample saltiness. These properties make 2 H peak integral an ideal parameter in esqNMR for correcting volume differences between the reference standard and analyte. We demonstrate a novel and practical technique abbreviated as "2 H SOLCOR" (2 H SOLvent CORrected), where the 2 H peak integral from the solvent is used as a universal internal standard to correct volume variations in NMR tubes, thereby improving accuracy and precision of esqNMR method. Herein, this simple yet effective technique is described, and practical considerations for successful implementation are presented. 2 H SOLCOR can be applied anywhere esqNMR is used, including where precious samples need to be accurately quantified for qualification as an authentic analytical standard.
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Affiliation(s)
| | - William Kim
- School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Wei Wang
- Pfizer Woldwide R&D La Jolla Lab, San Diego, CA, USA
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Gathungu RM, Kautz R, Kristal BS, Bird SS, Vouros P. The integration of LC-MS and NMR for the analysis of low molecular weight trace analytes in complex matrices. MASS SPECTROMETRY REVIEWS 2020; 39:35-54. [PMID: 30024655 PMCID: PMC6339611 DOI: 10.1002/mas.21575] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 06/28/2018] [Indexed: 05/12/2023]
Abstract
This review discusses the integration of liquid chromatography (LC), mass spectrometry (MS), and nuclear magnetic resonance (NMR) in the comprehensive analysis of small molecules from complex matrices. We first discuss the steps taken toward making the three technologies compatible, so as to create an efficient analytical platform. The development of online LC-MS-NMR, highlighted by successful applications in the profiling of highly concentrated analytes (LODs 10 μg) is discussed next. This is followed by a detailed overview of the alternative approaches that have been developed to overcome the challenges associated with online LC-MS-NMR that primarily stem from the inherently low sensitivity of NMR. These alternative approaches include the use of stop-flow LC-MS-NMR, loop collection of LC peaks, LC-MS-SPE-NMR, and offline NMR. The potential and limitations of all these approaches is discussed in the context of applications in various fields, including metabolomics and natural product discovery.
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Affiliation(s)
- Rose M. Gathungu
- Department of Medicine, Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital and Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts
- Barnett Institute of Chemical and Biological Analysis and Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts
| | - Roger Kautz
- Barnett Institute of Chemical and Biological Analysis and Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts
| | - Bruce S. Kristal
- Department of Medicine, Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital and Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts
| | | | - Paul Vouros
- Barnett Institute of Chemical and Biological Analysis and Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts
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Bader CD, Panter F, Müller R. In depth natural product discovery - Myxobacterial strains that provided multiple secondary metabolites. Biotechnol Adv 2019; 39:107480. [PMID: 31707075 DOI: 10.1016/j.biotechadv.2019.107480] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 12/28/2022]
Abstract
In recognition of many microorganisms ability to produce a variety of secondary metabolites in parallel, Zeeck and coworkers introduced the term "OSMAC" (one strain many compounds) around the turn of the century. Since then, additional efforts focused on the systematic characterization of a single bacterial species ability to form multiple secondary metabolite scaffolds. With the beginning of the genomic era mainly initiated by a dramatic reduction of sequencing costs, investigations of the genome encoded biosynthetic potential and especially the exploitation of biosynthetic gene clusters of undefined function gained attention. This was seen as a novel means to extend range and diversity of bacterial secondary metabolites. Genome analyses showed that even for well-studied bacterial strains, like the myxobacterium Myxococcus xanthus DK1622, many biosynthetic gene clusters are not yet assigned to their corresponding hypothetical secondary metabolites. In contrast to the results from emerging genome and metabolome mining techniques that show the large untapped biosynthetic potential per strain, many newly isolated bacterial species are still used for the isolation of only one target compound class and successively abandoned in the sense that no follow up studies are published from the same species. This work provides an overview about myxobacterial bacterial strains, from which not just one but multiple different secondary metabolite classes were successfully isolated. The underlying methods used for strain prioritization and natural product discovery such as biological characterization of crude extracts against a panel of pathogens, in-silico prediction of secondary metabolite abundance from genome data and state of the art instrumental analytics required for new natural product scaffold discovery in comparative settings are summarized and classified according to their output. Furthermore, for each approach selected studies performed with actinobacteria are shown to underline especially innovative methods used for natural product discovery.
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Affiliation(s)
- Chantal D Bader
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany
| | - Fabian Panter
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany
| | - Rolf Müller
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Campus E8.1, 66123 Saarbrücken, Germany; German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany.
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Berlinck RGS, Monteiro AF, Bertonha AF, Bernardi DI, Gubiani JR, Slivinski J, Michaliski LF, Tonon LAC, Venancio VA, Freire VF. Approaches for the isolation and identification of hydrophilic, light-sensitive, volatile and minor natural products. Nat Prod Rep 2019; 36:981-1004. [DOI: 10.1039/c9np00009g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Water-soluble, volatile, minor and photosensitive natural products are yet poorly known, and this review discusses the literature reporting the isolation strategies for some of these metabolites.
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Affiliation(s)
| | - Afif F. Monteiro
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | - Ariane F. Bertonha
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | - Darlon I. Bernardi
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | - Juliana R. Gubiani
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | - Juliano Slivinski
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | | | | | - Victor A. Venancio
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | - Vitor F. Freire
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
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9
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Gomes NG, Pereira DM, Valentão P, Andrade PB. Hybrid MS/NMR methods on the prioritization of natural products: Applications in drug discovery. J Pharm Biomed Anal 2018; 147:234-249. [DOI: 10.1016/j.jpba.2017.07.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/27/2017] [Accepted: 07/28/2017] [Indexed: 12/17/2022]
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10
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Tiwari R, Ahire D, Kumar H, Sinha S, Chauthe SK, Subramanian M, Iyer R, Sarabu R, Bajpai L. Use of Hybrid Capillary Tube Apparatus on 400 MHz NMR for Quantitation of Crucial Low-Quantity Metabolites Using aSICCO Signal. Drug Metab Dispos 2017; 45:1215-1224. [PMID: 28935657 DOI: 10.1124/dmd.117.077073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/13/2017] [Indexed: 11/22/2022] Open
Abstract
Metabolites of new chemical entities can influence safety and efficacy of a molecule and often times need to be quantified in preclinical studies. However, synthetic standards of metabolites are very rarely available in early discovery. Alternate approaches such as biosynthesis need to be explored to generate these metabolites. Assessing the quantity and purity of these small amounts of metabolites with a nondestructive analytical procedure becomes crucial. Quantitative NMR becomes the method of choice for these samples. Recent advances in high-field NMR (>500 MHz) with the use of cryoprobe technology have helped to improve sensitivity for analysis of small microgram quantity of such samples. However, this type of NMR instrumentation is not routinely available in all laboratories. To analyze microgram quantities of metabolites on a routine basis with lower-resolution 400 MHz NMR instrument fitted with a broad band fluorine observe room temperature probe, a novel hybrid capillary tube setup was developed. To quantitate the metabolite in the sample, an artificial signal insertion for calculation of concentration observed (aSICCO) method that introduces an internally calibrated mathematical signal was used after acquiring the NMR spectrum. The linearity of aSICCO signal was established using ibuprofen as a model analyte. The limit of quantification of this procedure was 0.8 mM with 10 K scans that could be improved further with the increase in the number of scans. This procedure was used to quantify three metabolites-phenytoin from fosphenytoin, dextrophan from dextromethorphan, and 4-OH-diclofenac from diclofenac-and is suitable for minibiosynthesis of metabolites from in vitro systems.
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Affiliation(s)
- Ranjeet Tiwari
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Deepak Ahire
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Hemantha Kumar
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Sarmistha Sinha
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Siddheshwar Kisan Chauthe
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Murali Subramanian
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Ramaswamy Iyer
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Ramakanth Sarabu
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
| | - Lakshmikant Bajpai
- Discovery Analytical Sciences (R.T., H.K., S.K.C., R.S., L.B.) and Pharmaceutical Candidate Optimization (D.A., S.S., M.S.), Bristol-Myers Squibb-Biocon Research Center, Bangalore, India; and Pharmaceutical Candidate Optimization, Bristol-Myers Squibb, Princeton, New Jersey (R.I.)
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Brooks WC, Paguigan ND, Raja HA, Moy FJ, Cech NB, Pearce CJ, Oberlies NH. qNMR for profiling the production of fungal secondary metabolites. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:670-676. [PMID: 28024162 PMCID: PMC5459663 DOI: 10.1002/mrc.4571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 12/13/2016] [Accepted: 12/16/2016] [Indexed: 06/06/2023]
Abstract
Analysis of complex mixtures is a common challenge in natural products research. Quantitative nuclear magnetic resonance spectroscopy offers analysis of complex mixtures at early stages and with benefits that are orthogonal to more common methods of quantitation, including ultraviolet absorption spectroscopy and mass spectrometry. Several experiments were conducted to construct a methodology for use in analysis of extracts of fungal cultures. A broadly applicable method was sought for analysis of both pure and complex samples through use of an externally calibrated method. This method has the benefit of not contaminating valuable samples with the calibrant, and it passed scrutiny for line fitting and reproducibility. The method was implemented to measure the yield of griseofulvin and dechlorogriseofulvin from three fungal isolates. An isolate of Xylaria cubensis (coded MSX48662) was found to biosynthesize griseofulvin in the greatest yield, 149 ± 8 mg per fermentation, and was selected for further supply experiments. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Wilson C. Brooks
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, North Carolina 27402, United States
| | - Noemi D. Paguigan
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, North Carolina 27402, United States
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, North Carolina 27402, United States
| | - Franklin J. Moy
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, North Carolina 27402, United States
| | - Nadja B. Cech
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, North Carolina 27402, United States
| | - Cedric J. Pearce
- Mycosynthetix, Inc., 505 Meadowland Drive, Suite 103, Hillsborough, North Carolina 27278, United States
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, North Carolina 27402, United States
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Marshall DD, Powers R. Beyond the paradigm: Combining mass spectrometry and nuclear magnetic resonance for metabolomics. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 100:1-16. [PMID: 28552170 PMCID: PMC5448308 DOI: 10.1016/j.pnmrs.2017.01.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 01/04/2017] [Accepted: 01/08/2017] [Indexed: 05/02/2023]
Abstract
Metabolomics is undergoing tremendous growth and is being employed to solve a diversity of biological problems from environmental issues to the identification of biomarkers for human diseases. Nuclear magnetic resonance (NMR) and mass spectrometry (MS) are the analytical tools that are routinely, but separately, used to obtain metabolomics data sets due to their versatility, accessibility, and unique strengths. NMR requires minimal sample handling without the need for chromatography, is easily quantitative, and provides multiple means of metabolite identification, but is limited to detecting the most abundant metabolites (⩾1μM). Conversely, mass spectrometry has the ability to measure metabolites at very low concentrations (femtomolar to attomolar) and has a higher resolution (∼103-104) and dynamic range (∼103-104), but quantitation is a challenge and sample complexity may limit metabolite detection because of ion suppression. Consequently, liquid chromatography (LC) or gas chromatography (GC) is commonly employed in conjunction with MS, but this may lead to other sources of error. As a result, NMR and mass spectrometry are highly complementary, and combining the two techniques is likely to improve the overall quality of a study and enhance the coverage of the metabolome. While the majority of metabolomic studies use a single analytical source, there is a growing appreciation of the inherent value of combining NMR and MS for metabolomics. An overview of the current state of utilizing both NMR and MS for metabolomics will be presented.
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Affiliation(s)
- Darrell D Marshall
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, United States.
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Deane CD, Burkhart BJ, Blair PM, Tietz JI, Lin A, Mitchell DA. In Vitro Biosynthesis and Substrate Tolerance of the Plantazolicin Family of Natural Products. ACS Chem Biol 2016; 11:2232-43. [PMID: 27248686 PMCID: PMC4992447 DOI: 10.1021/acschembio.6b00369] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Plantazolicin (PZN) is a ribosomally synthesized and post-translationally modified peptide (RiPP) natural product that exhibits extraordinarily narrow-spectrum antibacterial activity toward the causative agent of anthrax, Bacillus anthracis. During PZN biosynthesis, a cyclodehydratase catalyzes cyclization of cysteine, serine, and threonine residues in the PZN precursor peptide (BamA) to azolines. Subsequently, a dehydrogenase oxidizes most of these azolines to thiazoles and (methyl)oxazoles. The final biosynthetic steps consist of leader peptide removal and dimethylation of the nascent N-terminus. Using a heterologously expressed and purified heterocycle synthetase, the BamA peptide was processed in vitro concordant with the pattern of post-translational modification found in the naturally occurring compound. Using a suite of BamA-derived peptides, including amino acid substitutions as well as contracted and expanded substrate variants, the substrate tolerance of the heterocycle synthetase was elucidated in vitro, and the residues crucial for leader peptide binding were identified. Despite increased promiscuity compared to what was previously observed during heterologous production in E. coli, the synthetase retained exquisite selectivity in cyclization of unnatural peptides only at positions which correspond to those cyclized in the natural product. A cleavage site was subsequently introduced to facilitate leader peptide removal, yielding mature PZN variants after enzymatic or chemical dimethylation. In addition, we report the isolation and characterization of two novel PZN-like natural products that were predicted from genome sequences but whose production had not yet been observed.
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Affiliation(s)
- Caitlin D. Deane
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Brandon J. Burkhart
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Patricia M. Blair
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jonathan I. Tietz
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Alice Lin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Douglas A. Mitchell
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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