On-Line Coupling of Separation Techniques to NMR

Albert, Klaus; Dachtler, Markus; Glaser, Tobias; Händel, Heidi; Lacker, Tanja; Schlotterbeck, Götz; Strohschein, Sabine; Tseng, Li‐Hong; Braumann, Ulrich

doi:10.1002/(sici)1521-4168(19990301)22:3<135::aid-jhrc135>3.3.co;2-q

Cited by 17 publications

(20 citation statements)

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“…Many useful results related to natural products have been obtained using direct HPLC-NMR methods [1] and the technique has been reviewed at various stages of its development [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18]. Pharmaceutical, biomedical and other applications of NMR hyphenation have also been extensively reviewed [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30]. However, the direct combination of state-of-the-art separation technology with the most powerful and versatile tool for structure elucidation of organic molecules in solution suffers from various practical problems.…”

Section: Introductionmentioning

confidence: 99%

Hyphenated NMR Methods in Natural Products Research, Part 2: HPLC-SPE-NMR and Other New Trends in NMR Hyphenation

2005

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IntroductionIn the first part of this review [1], the use of direct NMR hyphenation in natural products research has been discussed. The direct HPLC-NMR methods were defined as methods in which the NMR data acquisition is performed on the HPLC column eluate [1]. This implies either a direct connection between the NMR spectrometer and the HPLC apparatus, or use of storage capillaries in which the HPLC eluate is temporarily stored prior to acquisition of NMR data.Many useful results related to natural products have been obtained using direct HPLC-NMR methods [1] [30]. However, the direct combination of state-of-the-art separation technology with the most powerful and versatile tool for structure elucidation of organic molecules in solution suffers from various practical problems. In short, these practical limitations are due to somewhat contradictory requirements of HPLC and NMR with respect to solvents and time-scale of the experiment, and thus compromises are necessary in order to hyphenate these two techniques. For example, 1 H-NMR spectra are preferably acquired in deuterated solvents, but use of deuterated solvents for HPLC is expensive and the selection is limited. Some useful HPLC eluents, such as buffers with high ionic strengths, are directly undesirable in direct HPLC-NMR hyphenation. Gradient elution of HPLC columns, required in most separations, implies constantly changing magnetic susceptibility and field homogeneity in the NMR flowprobe, not to mention variations of analyte chemical shifts with solvent composition. Hyphenated NMR Methods in Natural Products AbstractThis review describes the principles and performance of a novel and highly promising hyphenated technique, HPLC-SPE-NMR, which is based on post-column analyte trapping by solid-phase extraction. The analytes are subsequently eluted from the SPE cartridges using deuterated solvents. This indirect HPLC-NMR hyphenation offers numerous advantages compared to direct HPLC-NMR methods. Multiple trapping leads to a dramatic increase of analyte amounts available for NMR, enabling acquisition of high-quality 2D NMR data within a short time. Other new developments, including combination of solenoidal coil capillary flow-probes with microflow HPLC, are also discussed. Fast extract dereplication using these techniques enables focusing of isolation efforts on truly novel and promising natural products, based on precise structural data obtained with crude extracts or fractions.

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Section: Introductionmentioning

confidence: 99%

Hyphenated NMR Methods in Natural Products Research, Part 2: HPLC-SPE-NMR and Other New Trends in NMR Hyphenation

2005

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“…13% of the total carotenoid content, where the hyphenation of HPLC with NMR as detector allowed their identification 9- Z , 13- Z , 9,13- ZZ, and 9,13′- ZZ geometrical isomers. Unfortunately, Z / E stereoisomers lead to the same mass spectra and fragmentation patters, even with LC-MS, and therefore they are not distinguishable by using HPLC-MS [ 19 , 20 ].…”

Section: Metabolomics Platform In Plant Sciencesmentioning

confidence: 99%

NMR Metabolomics Applied on the Discrimination of Variables Influencing Tomato (Solanum lycopersicum)

Abreu

Fernández

2020

Molecules

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Tomato composition and nutritional value are attracting increasing attention and interest from both consumers and producers. The interest in enhancing fruits’ quality with respect to beneficious nutrients and flavor/aroma components is based not only in their economic added value but also in their implications involving organoleptic and healthy properties and has generated considerable research interest among nutraceutical and horticultural industries. The present article reviews up to March 2020 some of the most relevant studies based on the application of NMR coupled to multivariate statistical analysis that have addressed the investigation on tomato (Solanum lycopersicum). Specifically, the NMR untargeted technique in the agri-food sector can generate comprehensive data on metabolic networks and is paving the way towards the understanding of variables affecting tomato crops and composition such as origin, variety, salt-water irrigation, cultivation techniques, stage of development, among many others. Such knowledge is helpful to improve fruit quality through cultural practices that divert the metabolism towards the desired pathways and, probably more importantly, drives further efforts towards the differentiation of those crops developed under controlled and desired agronomical conditions.

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“…NMR was introduced to provide solutions to these problems to yield data with high accuracy and swiness, [8][9][10] however, slow turnover for the dereplications of compounds Analyst PAPER and structure identication in mixtures caused drawbacks which hindered NMR for years from being the most routinely used technique. More recently the dereplication problem could be overcome by using hyphenation techniques 11,12 and once again makes NMR an attractive technique in drug discovery.…”

Section: Introductionmentioning

confidence: 99%

Crude to leads: a triple-pronged direct NMR approach in coordination with docking simulation

Tanoli

Bondancia

et al. 2013

Analyst

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The screening of compounds that bind to the target of interest (specific proteins) plays a vital role in drug discovery. Usually, the identification of biologically active compounds is done from a library of structurally known compounds. However, we successfully illustrate here, that NMR techniques including saturation transfer difference (STD), transfer nuclear Overhauser spectroscopy (TrNOESY) and STD-TOCSY (total correlation spectroscopy) in combination with separation methods not only enable the rapid and comprehensive screening of active components, but also their unequivocal structural characterization. Furthermore, a time saving for the recognition of leads is also possible with this application. To probe the binding studies, a hydroethanolic fraction of crude extract (1 mg) from natural product (Rauia resinous) was used for the initial assessment with BSA protein. The docking simulation was performed with BSA in the region of Thr190, Arg198, Arg217, Trp213, Arg256, Ala290 and Tyr451 to further refine the active compound towards the leads. Docking results mimic binding as identified by STD, Tr-NOESY and STD-TOCSY. Isovetexine-2-rhamnosoide (2) was found to be most active through group epitope mapping results as well as the docking simulation with relative free energy of -7.2770. This experiment provided excellent results through the direct NMR screening method. Using Bovine Serum Albumin as a reference, we illustrate that this approach offers an excellent way for the first hand detection of the active constituents/inhibitors from natural remedies used in folk medicinal treatments.

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On-Line Coupling of Separation Techniques to NMR

Cited by 17 publications

References 0 publications

Hyphenated NMR Methods in Natural Products Research, Part 2: HPLC-SPE-NMR and Other New Trends in NMR Hyphenation

Hyphenated NMR Methods in Natural Products Research, Part 2: HPLC-SPE-NMR and Other New Trends in NMR Hyphenation

NMR Metabolomics Applied on the Discrimination of Variables Influencing Tomato (Solanum lycopersicum)

Crude to leads: a triple-pronged direct NMR approach in coordination with docking simulation

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