Optimizing NMR Methods for Structure Elucidation

Two new iridoids, 10-O-benzoylglobularigenin (1) and dumuloside (2) were isolated from the aerial parts of Globularia dumulosa together with seven known iridoid glucosides, davisioside (3), aucubin (4), melampyroside (5), catalpol (6), 10-O-benzoylcatalpol (7), alpinoside (8) and deacetylalpinoside (9). Three phenylethanoid glycosides, verbascoside, decaffeoylverbascoside, leucosceptoside A and three flavone glucosides, pectolinarigenin 7-O-β-ᴅ-glucopyranoside, nepetin 7-O-β-ᴅ-glucopyranoside, demethoxycentaureidin 7-O-β-ᴅ-glucopyranoside were also isolated and characterized. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, HR-MALDIMS, 1D- and 2D NMR) methods.

Download Full-text

Assigning regioisomeric or diastereoisomeric relations of problematic trisubstituted double-bonds through heteronuclear 2D selective J-resolved NMR spectroscopy

RSC Advances ◽

10.1039/c5ra03228h ◽

2015 ◽

Vol 5 (47) ◽

pp. 37138-37148 ◽

Cited By ~ 5

Author(s):

Marie Hoffmann ◽

Solène Miaskiewicz ◽

Jean-Marc Weibel ◽

Patrick Pale ◽

Aurélien Blanc

Keyword(s):

Nmr Spectroscopy ◽

Natural Product ◽

Structure Elucidation ◽

2D Nmr ◽

Double Bonds ◽

Nmr Methods

Although one of the first 2D NMR methods, but so far neglected, selectiveJ-resolved NMR spectroscopy offers a unique opportunity to help organic chemists in structure elucidation, avoiding natural and non-natural product misassignments.

Download Full-text

ChemInform Abstract: Non-NMR Methods for Structure Elucidation of Saponins

ChemInform ◽

10.1002/chin.200115297 ◽

2001 ◽

Vol 32 (15) ◽

pp. no-no

Author(s):

T. Schopke

Keyword(s):

Structure Elucidation ◽

Nmr Methods

Download Full-text

Review of Optimizing NMR Methods for Structure Elucidation: Characterizing Natural Products and Other Organic Compounds (New Developments in NMR)

Journal of Natural Products ◽

10.1021/acs.jnatprod.0c01046 ◽

2020 ◽

Vol 83 (12) ◽

pp. 3764-3764

Author(s):

Skylar Carlson

Keyword(s):

Natural Products ◽

Organic Compounds ◽

Structure Elucidation ◽

New Developments ◽

Nmr Methods

Download Full-text

Sharpening Up Your Spectra: Broadband Homonuclear Decoupling in HSQC by Real-Time Pure Shift Acquisition

Synlett ◽

10.1055/s-0037-1612057 ◽

2019 ◽

Vol 30 (09) ◽

pp. 1015-1025 ◽

Cited By ~ 2

Author(s):

Peter Kiraly ◽

Gareth Morris ◽

Liu Quanxiu ◽

Mathias Nilsson

Keyword(s):

Nmr Spectroscopy ◽

Real Time ◽

Structure Elucidation ◽

Method Development ◽

Pulse Sequences ◽

Resolution Enhancement ◽

Daily Routine ◽

Two Factors ◽

Nmr Methods ◽

Processing Techniques

Structure elucidation using NMR spectroscopy has become a vital part of the toolkit of modern synthetic chemistry. Characterisation of final products, quality control of production, analysis of complex mixtures in synthetic method development, and structure elucidation of isolated natural products are examples where NMR spectroscopy is a part of daily routine. The two factors that usually limit the applicability of NMR are resolution and sensitivity. The experimental method described in this Account, real-time pure shift acquisition, yields heteronuclear correlation spectra such as HSQC that offer significant improvements in both resolution and sensitivity, at negligible cost to the analyst. The advantages that real-time pure shift acquisition enjoys over conventional experiments are discussed and illustrated with selected examples including carbohydrate and alkaloid mixtures. Advanced data acquisition and processing techniques that reduce experiment time and are easily combined with pure shift NMR methods are also described.1 Introduction2 Simultaneous Sensitivity and Resolution Enhancement Using Real-Time Acquisition in HSQC3 Processing Pure Shift Data4 Pulse Sequences for Real-Time Pure Shift HSQC5 Conclusions and Future Perspectives

Download Full-text