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Feineis D, Bringmann G. Structural variety and pharmacological potential of naphthylisoquinoline alkaloids. THE ALKALOIDS. CHEMISTRY AND BIOLOGY 2024; 91:1-410. [PMID: 38811064 DOI: 10.1016/bs.alkal.2024.03.001] [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: 05/31/2024]
Abstract
Naphthylisoquinoline alkaloids are a fascinating class of natural biaryl compounds. They show characteristic mono- and dimeric scaffolds, with chiral axes and stereogenic centers. Since the appearance of the last comprehensive overview on these secondary plant metabolites in this series in 1995, the number of discovered representatives has tremendously increased to more than 280 examples known today. Many novel-type compounds have meanwhile been discovered, among them naphthylisoquinoline-related follow-up products like e.g., the first seco-type (i.e., ring-opened) and ring-contracted analogues. As highlighted in this review, the knowledge on the broad structural chemodiversity of naphthylisoquinoline alkaloids has been decisively driven forward by extensive phytochemical studies on the metabolite pattern of Ancistrocladus abbreviatus from Coastal West Africa, which is a particularly "creative" plant. These investigations furnished a considerable number of more than 80-mostly new-natural products from this single species, with promising antiplasmodial activities and with pronounced cytotoxic effects against human leukemia, pancreatic, cervical, and breast cancer cells. Another unique feature of naphthylisoquinoline alkaloids is their unprecedented biosynthetic origin from polyketidic precursors and not, as usual for isoquinoline alkaloids, from aromatic amino acids-a striking example of biosynthetic convergence in nature. Furthermore, remarkable botanical results are presented on the natural producers of naphthylisoquinoline alkaloids, the paleotropical Dioncophyllaceae and Ancistrocladaceae lianas, including first investigations on the chemoecological role of these plant metabolites and their storage and accumulation in particular plant organs.
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Affiliation(s)
- Doris Feineis
- Institute of Organic Chemistry, University of Würzburg, Würzburg, Germany
| | - Gerhard Bringmann
- Institute of Organic Chemistry, University of Würzburg, Würzburg, Germany.
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Feineis D, Bringmann G. Asian Ancistrocladus Lianas as Creative Producers of Naphthylisoquinoline Alkaloids. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2023; 119:1-335. [PMID: 36587292 DOI: 10.1007/978-3-031-10457-2_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This book describes a unique class of secondary metabolites, the mono- and dimeric naphthylisoquinoline alkaloids. They occur in lianas of the paleotropical Ancistrocladaceae and Dioncophyllaceae families, exclusively. Their unprecedented structures include stereogenic centers and rotationally hindered, and thus likewise stereogenic, axes. Extended recent investigations on six Ancistrocladus species from Asia, as reported in this review, shed light on their fascinating phytochemical productivity, with over 100 such intriguing natural products. This high chemodiversity arises from a likewise unique biosynthesis from acetate-malonate units, following a novel polyketidic pathway to plant-derived isoquinoline alkaloids. Some of the compounds show most promising antiparasitic activities. Likewise presented are strategies for the regio- and stereoselective total synthesis of the alkaloids, including the directed construction of the chiral axis.
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Affiliation(s)
- Doris Feineis
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Gerhard Bringmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
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Tajuddeen N, Bringmann G. N, C-Coupled naphthylisoquinoline alkaloids: a versatile new class of axially chiral natural products. Nat Prod Rep 2021; 38:2154-2186. [PMID: 34212956 DOI: 10.1039/d1np00020a] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Covering: up to April 2021During the past decades, a plethora of natural products with restricted rotation about a biaryl axis have been discovered, among them the naphthylisoquinoline (NIQ) alkaloids, mostly C,C-coupled and having remarkable bioactivities. Within this fascinating class of naturally occurring biaryl compounds, NIQ alkaloids bearing an N,C-heterobiaryl axis have attracted particular attention. They are structurally and biosynthetically unprecedented, with interesting stereochemical implications and biological activities. In contrast to existing articles and reviews about axially chiral - yet C,C-coupled - natural products, this is the first, comprehensive review on the new subclass of N,C-coupled NIQs, their isolation and structural elucidation, their N,C-axial chirality, their biosynthetic origin, their promising antiparasitic and antileukemic activities, and their total synthesis.
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Affiliation(s)
- Nasir Tajuddeen
- Department of Chemistry, Ahmadu Bello University, Zaria, Nigeria
| | - Gerhard Bringmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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LC–NMR for Natural Product Analysis: A Journey from an Academic Curiosity to a Robust Analytical Tool. SCI 2021. [DOI: 10.3390/sci3010006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Liquid chromatography (LC)–nuclear magnetic resonance (NMR) combines the advantage of the outstanding separation power of liquid chromatography (LC) and the superior structural elucidating capability of nuclear magnetic resonance (NMR). NMR has proved that it is a standout detector for LC by providing maximum structural information about plant originated extracts, particularly on the isolating ability of isomeric (same molecular formula) and/or isobaric (same molecular weight) compounds as compared to other detectors. The present review provides an overview of the developmental trends and application of LC–NMR in natural product analysis. The different LC–NMR operational modes are described, and how technical improvements assist in establishing this powerful technique as an important analytical tool in the analysis of complex plant-derived compounds is also highlighted. On-flow, stop-flow and loop-storage modes, as well as the new offline mode LC–solid phase extraction (SPE)–NMR and capillary LC (capLC)–NMR configurations which avoid the ingestion of expensive deuterated solvents throughout the experiment, are mentioned. Utilization of cryogenic probe and microprobe technologies, which are the other important promising approaches for guaranteeing sensitivity, are also described. Concluding remarks and future outlooks are also discussed.
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LC-NMR for Natural Products Analysis: A Journey from an Academic Curiosity to a Robust Analytical Tool. SCI 2019. [DOI: 10.3390/sci1010031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
LC–NMR combines the advantage of the outstanding separation power of liquid chromatography (LC) and the superior structural elucidating capability of nuclear magnetic resonance (NMR). NMR has proved that it is a standout detector for LC by providing maximum structural information about plant originated extracts particularly in its isolating ability of isomeric (same molecular formula) and/or isobaric (same molecular weight) compounds as compared to other detectors. The present review provides an overview of the LC–NMR developmental trends and its application in natural products analysis. The different LC–NMR operational modes are described, as well as how technical improvements assist in establishing this powerful technique as an important analytical tool in the analysis of complex plant-derived compounds. On-flow, stop-flow and loop-storage modes, as well as the new offline mode LC–SPE–NMR and capLC-NMR configurations that avoid the ingestion of expensive deuterated solvents throughout the experiment are mentioned. Utilization of cryogenic probe and microprobe technologies which are the other important promising approaches for guaranteeing the sensitivity issues are also described. Concluding remarks and future outlooks are also discussed.
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Lombe BK, Feineis D, Bringmann G. Dimeric naphthylisoquinoline alkaloids: polyketide-derived axially chiral bioactive quateraryls. Nat Prod Rep 2019; 36:1513-1545. [DOI: 10.1039/c9np00024k] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This is the first review on dimeric naphthylisoquinolines, a group of structurally intriguing, biosynthetically unique, and pharmacologically promising alkaloids.
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Affiliation(s)
- Blaise Kimbadi Lombe
- Institute of Organic Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
- Faculté des Sciences
| | - Doris Feineis
- Institute of Organic Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - Gerhard Bringmann
- Institute of Organic Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
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Mannina L, D'Imperio M, Gobbino M, D'Amico I, Casini A, Emanuele MC, Sobolev AP. Nuclear magnetic resonance study of flavoured olive oils. FLAVOUR FRAG J 2012. [DOI: 10.1002/ffj.3094] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Marco Gobbino
- CNR; Istituto di Metodologie Chimiche, Laboratorio di Risonanza Magnetica “Annalaura Segre”; I-00015; Monterotondo Staz.; Rome; Italy
| | - Irene D'Amico
- Università del Molise; Dipartimento S.T.A.A.M.; Via F. De Sanctis snc; I-86100; Campobasso; Italy
| | - Antonio Casini
- Sapienza Università di Roma; Dipartimento di Chimica e Tecnologie del Farmaco; P.le Aldo Moro 5; I-00185; Rome; Italy
| | | | - Anatoly P. Sobolev
- CNR; Istituto di Metodologie Chimiche, Laboratorio di Risonanza Magnetica “Annalaura Segre”; I-00015; Monterotondo Staz.; Rome; Italy
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Wixom RL. The Trails of Research in Chromatography. CHROMATOGRAPHY 2010. [DOI: 10.1002/9780470555729.ch4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bringmann G, Gulder TA, Reichert M, Gulder T. The online assignment of the absolute configuration of natural products: HPLC-CD in combination with quantum chemical CD calculations. Chirality 2008; 20:628-42. [DOI: 10.1002/chir.20557] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Miliauskas G, van Beek TA, de Waard P, Venskutonis RP, Sudhölter EJR. Comparison of analytical and semi-preparative columns for high-performance liquid chromatography–solid-phase extraction–nuclear magnetic resonance. J Chromatogr A 2006; 1112:276-84. [PMID: 16364345 DOI: 10.1016/j.chroma.2005.11.059] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Revised: 11/07/2005] [Accepted: 11/08/2005] [Indexed: 11/21/2022]
Abstract
The application of analytical and semi-preparative columns in reversed-phase liquid chromatography-solid-phase extraction-nuclear magnetic resonance (HPLC-SPE-NMR) was compared. The work was aiming at separating a higher sample amount in a single run and in this way to reduce the necessary NMR measurement time of separated compounds. Several parameters for compound separation and trapping procedures were optimised: flow rate of HPLC and make-up water pumps, choice of stationary phase cartridges and drying time. The separation and loadability of nine model compounds on analytical and semi-preparative columns was determined, as well as the focussing capacity of SH-type SPE cartridges. It was found that a semi-preparative column--or multiple peak trapping on analytical columns--gave better results than a standard 4.6mm analytical column for non-polar compounds (e.g. flavonoid aglycones, sesquiterpene lactones, non-polar terpenes, logP>2), but for polar compounds (logP<-2) did not offer any advantage over an analytical column, or was even disadvantageous. For intermediately polar compounds (-2<logP<2) this has to be investigated per compound.
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Affiliation(s)
- Giedrius Miliauskas
- Laboratory of Organic Chemistry, Natural Products Chemistry Group, Wageningen University, Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
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Pham LH, Vater J, Rotard W, Mügge C. Identification of secondary metabolites from Streptomyces violaceoruber TU22 by means of on-flow LC-NMR and LC-DAD-MS. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2005; 43:710-23. [PMID: 16049955 DOI: 10.1002/mrc.1633] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
For rapid screening of natural products from Actinomycetes, a combination of on-line couplings LC-NMR, LC-DAD-MS and HPLC-PDA, as well as MALDI-TOF-MS is particularly suitable. Simultaneous use of these coupling techniques provides considerable advantages for the rapid identification of natural compounds in mixtures. The results of our present investigation on secondary metabolite products of Streptomyces violaceoruber TU 22 showed that more than 50% of the identified metabolites are new compounds. The structures of four new polyketides (granaticin C, metenaticin A, B and C) as well as four known ones (granaticin A, granatomycin E, daidzein and genistein) have been elucidated using LC-NMR, LC-MS/MS and -MS(n) techniques in combination with two-dimensional NMR spectroscopy.
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Affiliation(s)
- L H Pham
- Inst. f. Chemie, AG Biochemie u. Molekulare Biologie, Technische Universität Berlin, Germany
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Exarchou V, Krucker M, van Beek TA, Vervoort J, Gerothanassis IP, Albert K. LC-NMR coupling technology: recent advancements and applications in natural products analysis. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2005; 43:681-7. [PMID: 16049952 DOI: 10.1002/mrc.1632] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
An overview of recent advances in nuclear magnetic resonance (NMR) coupled with separation technologies and their application in natural product analysis is given and discussed. The different modes of LC-NMR operation are described, as well as how technical improvements assist in establishing LC-NMR as an important tool in the analysis of plant-derived compounds. On-flow, stopped-flow and loop-storage procedures are mentioned, together with the new LC-SPE-NMR configuration. The implementation of mass spectrometry in LC-NMR is also useful on account of the molecular weight and fragmentation information that it provides, especially when new plant species are studied. Cryogenic technology and capillary LC-NMR are the other important recent developments. Since the plant kingdom is endless in producing potential drug candidates, development and optimization of LC-NMR techniques convert the study of natural products to a less-time-consuming task, speeding up identification.
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Bringmann G, Lang G, Mühlbacher J, Schaumann K, Steffens S, Rytik PG, Hentschel U, Morschhäuser J, Müller WEG. Sorbicillactone A: a structurally unprecedented bioactive novel-type alkaloid from a sponge-derived fungus. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2005; 37:231-53. [PMID: 15825646 DOI: 10.1007/978-3-642-55519-0_9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
This chapter deals with the discovery of sorbicillactone A, as an illustrative example of the fruitful cooperation within BIOTECmarin--its isolation and chemical characterization, and its biological activities. Sorbicillactone A was isolated from a strain of Penicillium chrysogenum cultured from a sample of the Mediterranean sponge Ircinia fasciculata; it possesses a unique bicyclic lactone structure, seemingly derived from sorbicillin. Among the numerous known sorbicillin-derived structures, it is the first found to contain nitrogen and thus the first representative of a novel type of 'sorbicillin alkaloids', apparently originating from a likewise remarkable biosynthesis. Furthermore, the compound exhibits promising activities in several mammalian and viral test systems, in particular a highly selective cytostatic activity against murine leukemic lymphoblasts (L5178y) and the ability to protect human T cells against the cytopathic effects of HIV-1. These properties qualify sorbicillactone A or one of its derivatives for animal and (hopefully) also future therapeutic human trials.
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Affiliation(s)
- G Bringmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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Mesnard F, Ratcliffe RG. NMR analysis of plant nitrogen metabolism. PHOTOSYNTHESIS RESEARCH 2005; 83:163-80. [PMID: 16143850 DOI: 10.1007/s11120-004-2081-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2004] [Accepted: 07/17/2004] [Indexed: 05/04/2023]
Abstract
The analysis of primary and secondary nitrogen metabolism in plants by nuclear magnetic resonance (NMR) spectroscopy is comprehensively reviewed. NMR is a versatile analytical tool, and the combined use of (1)H, (2)H, (13)C, (14)N and (15)N NMR allows detailed investigation of the acquisition, assimilation and metabolism of nitrogen. The analysis of tissue extracts can be complemented by the in vivo NMR analysis of functioning tissues and cell suspensions, and by the application of solid state NMR techniques. Moreover stable isotope labelling with (2)H-, (13)C- and (15)N-labelled precursors provides direct insight into specific pathways, with the option of both time-course and steady state analysis increasing the potential value of the approach. The scope of the NMR method, and its contribution to studies of plant nitrogen metabolism, are illustrated with a wide range of examples. These include studies of the GS/GOGAT pathway of ammonium assimilation, investigations of the metabolism of glutamate, glycine and other amino acids, and applications to tropane alkaloid metabolism. The continuing development of the NMR technique, together with potential applications in the emerging fields of metabolomics and metabolic flux analysis, leads to the conclusion that NMR will play an increasingly valuable role in the analysis of plant nitrogen metabolism.
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Affiliation(s)
- F Mesnard
- EA 2084, Faculté de Pharmacie, Laboratoire de Phytotechnologie, 1 rue des Louvels, F-80037 Amiens Cedex 1, France
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Bringmann G, Lang G. Full absolute stereostructures of natural products directly from crude extracts: The HPLC-MS/ MS-NMR-CD 'triad'. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2003; 37:89-116. [PMID: 15825641 DOI: 10.1007/978-3-642-55519-0_4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
This chapter deals with an efficient methodology available in our Center of Excellence, BIOTECmarin: the novel analytical 'triad' HPLC-MS/MS-NMR-CD. By this method, which was, in this complemented form, first introduced into phytochemical research by our group, we can not only rapidly identify known structures, but can also investigate new metabolites and establish their full absolute stereostructures online, directly from crude extracts, without the necessity of first isolating the compounds. The LC-CD option, which we have been using for the first time in natural products analysis, becomes even more valuable by the possibility of interpreting the online CD spectra by their simulation or prediction through quantum chemical calculation, thus avoiding the usual, often risky, empirical comparison with the CD spectra of (sometimes not so related) compounds of known absolute stereostructure or the application of (sometimes not really applicable) likewise empirical CD rules. The hyphenated analytical methods are additionally complemented by our synthetic expertise, again involving new concepts and strategies developed in our group. The methods and their application will first be explained and exemplified for plant-derived ('terrestrial') natural products, for which they were initially developed, and will then be applied to the online structural elucidation of novel natural products from marine organisms.
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Affiliation(s)
- G Bringmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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Simultaneous enantioresolution and assignment of absolute configuration of secondary alcohols by directly coupled HPLC–NMR of 9-AMA esters. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00510-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Bringmann G, Günther C, Ochse M, Schupp O, Tasler S. Biaryls in nature: a multi-facetted class of stereochemically, biosynthetically, and pharmacologically intriguing secondary metabolites. FORTSCHRITTE DER CHEMIE ORGANISCHER NATURSTOFFE = PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS. PROGRES DANS LA CHIMIE DES SUBSTANCES ORGANIQUES NATURELLES 2002; 82:1-249. [PMID: 11892255 DOI: 10.1007/978-3-7091-6227-9_1] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- G Bringmann
- Institut für Organische Chemie, Universität Würzburg, Germany.
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Bringmann G, Wohlfarth M, Rischer H, Heubes M, Saeb W, Diem S, Herderich M, Schlauer J. A photometric screening method for dimeric naphthylisoquinoline alkaloids and complete on-line structural elucidation of a dimer in crude plant extracts, by the LC-MS/LC-NMR/LC-CD triad. Anal Chem 2001; 73:2571-7. [PMID: 11403302 DOI: 10.1021/ac001503q] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient evaluation procedure for the chemical screening and on-line structural elucidation of dimeric naphthylisoquinoline alkaloids has been developed. The method is based on the lead tetraacetate oxidation of the central binaphthalene core of the alkaloids. UV spectra of the extracts after addition of the oxidant show, in the presence of naphthylisoquinoline dimers, the appearance of a characteristic long-wavelength absorption indicative of dinaphthoquinones. The efficiency and relevance of the method has been demonstrated in the discovery of a constitutionally and configurationally new dimeric naphthylisoquinoline alkaloid, named ancistrogriffithine A (4), from the previously uninvestigated Asian liana Ancistrocladus griffithii. After verification of this screening result by LC-ESI-MS/MS, the constitution and the relative configuration of the compound were elucidated on line, by LC-NMR and LC-CD on the extract. Using an LC-NMR-WET-ROESY experiment, itwas possible for the first time to determine the relative axial configuration of a natural biaryl compound on line, by observing long-range ROE interactions. Finally, an oxidative degradation right on the extract delivered the absolute configuration of 4, without isolation of the alkaloid. Ancistrogriffithine A is the as yet only dimeric naphthylisoquinoline from an Asian Ancistrocladaceae plant.
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Affiliation(s)
- G Bringmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, Germany.
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Sandvoss M, Weltring A, Preiss A, Levsen K, Wuensch G. Combination of matrix solid-phase dispersion extraction and direct on-line liquid chromatography-nuclear magnetic resonance spectroscopy-tandem mass spectrometry as a new efficient approach for the rapid screening of natural products: application to the total asterosaponin fraction of the starfish Asterias rubens. J Chromatogr A 2001; 917:75-86. [PMID: 11403494 DOI: 10.1016/s0021-9673(01)00668-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A combination of matrix solid-phase dispersion extraction (MSPD) and LC-NMR-MS hyphenation is proposed as a rapid screening method of natural products for unknown compounds. In this report, this new analytical approach is applied for the first time. MSPD represents a significant simplification compared to classical extraction procedures and is thus an excellent complement to the fast and powerful LC-NMR-MS: MSPD yields extracts suitable for LC-NMR-MS in one simple preparation step, while LC-NMR-MS yields a wealth of information in one single chromatographic run. The suitability of this technique to characterise glycosidic compounds in the molecular mass range of 1200 to 1400 a.m.u. is demonstrated. The information on the number of exchangeable protons provided by an additional back-exchange experiment proved to be particularly valuable for structural elucidation. The possibility of semi-quantitative LC-NMR measurements through methyl signals H(3)-18 and 19 of the steroidal skeleton is demonstrated and is ensuingly used to provide relative quantitative data of the steroid oligosaccharide fraction.
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Affiliation(s)
- M Sandvoss
- Fraunhofer-Institut für Toxikologie und Aerosolforschung, Abteilung Bio- und Umweltanalytik, Hannover, Germany
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Exarchou V, Troganis A, Gerothanassis IP, Tsimidou M, Boskou D. Identification and quantification of caffeic and rosmarinic acid in complex plant extracts by the use of variable-temperature two-dimensional nuclear magnetic resonance spectroscopy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:2-8. [PMID: 11302111 DOI: 10.1021/jf990928e] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A combination of advanced nuclear magnetic resonance (NMR) methodologies for the analysis of complex phenolic mixtures that occur in natural products is described, with particular emphasis on caffeic acid and its ester derivative, rosmarinic acid. The combination of variable-temperature two-dimensional proton-proton double quantum filter correlation spectroscopy (1H-1H DQF COSY) and proton-carbon heteronuclear multiple quantum coherence (1H-13C HMQC) gradient NMR spectroscopy allows the identification and tentative quantification of caffeic and rosmarinic acids at 243 K in extracts from plants of the Lamiaceae family, without resorting to previous chromatographic separation of the components. The use of proton-carbon heteronuclear multiple bond correlation (1H-13C HMBC) gradient NMR spectroscopy leads to the complete assignment of the correlations of the spins of H2a and H3a with the ester and carboxyl carbons of rosmarinic and caffeic acid, even at room temperature, and confirms the results of the above methodology Quantitative results are in reasonable agreement with reverse phase HPLC measurements.
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Affiliation(s)
- V Exarchou
- Department of Chemistry, University of Ioannina, Greece
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Abstract
The coupling of high performance liquid chromatography with nuclear magnetic resonance spectroscopy (LC-NMR) is one of the most powerful methods for the separation and structural elucidation of unknown compounds in mixtures. The recent progress in pulse field gradients and solvent suppression, the improvement in probe technology, and the construction of high field magnets have given a new stimulus to this technique, which has emerged since the mid 1990s as a very efficient method for the on-line identification of organic molecules. LC-NMR thus represents a potentially interesting complementary technique to LC-UV-MS in phytochemical analysis for the detailed on-line structural analysis of natural products. Recent applications have fully demonstrated the usefulness of this technique. A brief review of the applications of LC-NMR in natural product chemistry is presented in this paper, and a summary of the basic principles and modes of operation of LC-NMR is provided. Selected examples of LC-NMR analyses of plant metabolites in crude extracts or in enriched fractions are outlined and used to illustrate the different strategies for employing the technique. The practical possibilities and limitations of LC-NMR in its application to the analysis of crude plant extracts are discussed by means of several examples. Analytical strategies involving LC multi-coupled (hyphenated) techniques for the chemical screening and dereplication of crude plant extracts are presented. An analysis of the future development of the technique with respect to its application in phytochemical analysis is also given.
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Affiliation(s)
- J L Wolfender
- Institute of Pharmacognosy and Phytochemistry, University of Lausanne, BEP, CH-1015 Lausanne, Switzerland
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Bringmann G, Wohlfarth M, Heubes M. Observation of exchangeable protons by high-performance liquid chromatography-nuclear magnetic resonance spectroscopy and high-performance liquid chromatography-electrospray ionization mass spectrometry: a useful tool for the hyphenated analysis of natural products. J Chromatogr A 2000; 904:243-9. [PMID: 11204237 DOI: 10.1016/s0021-9673(00)00926-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The first high-performance liquid chromatography-nuclear magnetic resonance (HPLC-NMR) investigation of exchangeable protons of low-molecular-mass natural products is reported. Model alkaloids or crude plant extracts were dissolved in 2H2O-1H2O-MeCN (deuterium oxide-water-acetonitrile) or 2H2O-MeCN and, after direct injection or chromatographic separation, examined in a 60-microl NMR flow probe. Exchangeable amino protons initially detected by HPLC-electrospray ionization mass spectrometry were subsequently identified and investigated by stop-flow 1H-NMR, two-dimensional (2D) total correlation spectroscopy (TOCSY), and 2D nuclear Overhauser effect spectroscopy (NOESY). These experiments extend the applicability of HPLC-NMR for the investigation and structure elucidation of natural products.
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Affiliation(s)
- G Bringmann
- Institute of Organic Chemistry, University of Würzburg, Germany.
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Fabre N, Claparols C, Richelme S, Angelin ML, Fourasté I, Moulis C. Direct characterization of isoquinoline alkaloids in a crude plant extract by ion-pair liquid chromatography-electrospray ionization tandem mass spectrometry: example of Eschscholtzia californica. J Chromatogr A 2000; 904:35-46. [PMID: 11209899 DOI: 10.1016/s0021-9673(00)00919-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An ion-pair HPLC-ESI-MS-MS method has been developed for the direct and rapid characterization of isoquinoline alkaloids in a crudely purified extract of the aerial parts of Eschscholtzia californica (Papaveraceae). This plant was chosen because of its increasing use in pharmaceutical industries and because its well known alkaloid composition allows the optimization of the experimental procedure through an on-line analytical sequence. Thus, 14 isoquinoline alkaloids of different types were detected and characterized. The identities of these compounds were confirmed unambigously by their fragmentation and UV spectra obtained by LC-diode-array detection. Various experiments including tandem mass spectrometry and in-orifice collision induced dissociation were performed and prove that MS-MS is a very efficient technique to identify these compounds. An explanation for each isoquinoline alkaloid type MS-MS fragmentation pattern is proposed and indicates similar neutral and/or radical losses. The order of the fragmentation depended on the type of compound but the lost fragments were similar.
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Affiliation(s)
- N Fabre
- Laboratoire Pharmacophores Redox, Phytochimie et Radiobiologie, Université Paul Sabatier, Faculté des Sciences Pharmaceutiques, Toulouse, France.
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Kleinwächter P, Martin K, Groth I, Dornberger K. Use of Coupled HPLC/1H NMR and HPLC/ESI-MS for the Detection and Identification of (2E,4Z)-Decadienoic Acid from a NewAgromyces Species. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1521-4168(20001001)23:10<609::aid-jhrc609>3.0.co;2-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sandvoss M, Pham L, Levsen K, Preiss A, Mügge C, Wünsch G. Isolation and Structural Elucidation of Steroid Oligoglycosides from the StarfishAsteriasrubens by Means of Direct Online LC-NMR-MS Hyphenation and One- and Two-Dimensional NMR Investigations. European J Org Chem 2000. [DOI: 10.1002/1099-0690(200004)2000:7<1253::aid-ejoc1253>3.0.co;2-g] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Subramanian R, Kelley WP, Floyd PD, Tan ZJ, Webb AG, Sweedler JV. A microcoil NMR probe for coupling microscale HPLC with on-line NMR spectroscopy. Anal Chem 1999; 71:5335-9. [PMID: 10596212 DOI: 10.1021/ac990876s] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An HPLC NMR system is presented that integrates a commercial microbore HPLC system using a 0.5-mm column with a 500-MHz proton NMR spectrometer using a custom NMR probe with an observe volume of 1.1 microL and a coil fill factor of 68%. Careful attention to capillary connections and NMR flow cell design allows on-line NMR detection with no significant loss in separation efficiency when compared with a UV chromatogram. HPLC NMR is performed on mixtures of amino acids and small peptides with analyte injection amounts as small as 750 ng; the separations are accomplished in less than 10 min and individual NMR spectra are acquired with 12 s time resolution. Stopped-flow NMR is achieved by diversion of the chromatographic flow after observation of the beginning of the analyte band within the NMR flow cell. Isolation of the compound of interest within the NMR detection cell allows multidimensional experiments to be performed. A stopped-flow COSY spectrum of the peptide Phe-Ala is acquired in 3.5 h with an injected amount of 5 micrograms.
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Affiliation(s)
- R Subramanian
- Department of Chemistry, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign 61801, USA
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Bringmann G, Messer K, Wohlfarth M, Kraus J, Dumbuya K, Rückert M. HPLC−CD On-Line Coupling in Combination with HPLC−NMR and HPLC−MS/MS for the Determination of the Full Absolute Stereostructure of New Metabolites in Plant Extracts. Anal Chem 1999. [DOI: 10.1021/ac990001d] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Rückert M, Wohlfarth M, Bringmann G. Characterization of protein mixtures by ion-exchange chromatography coupled on-line to nuclear magnetic resonance spectroscopy. J Chromatogr A 1999. [DOI: 10.1016/s0021-9673(99)00200-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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