The NMR pulse sequence design strategy of NORD (NO Relaxation Delay) is extended to design of two new three-module experiments, NORD {HMBC}-{HSQC-TOCSY}-{TOCSY} and NORD {HMBC}-{2BOB}-{TOCSY}, each delivering four spectra - HMBC, HSQC, TOCSY, and either HSQC-TOCSY or H2BC. Compared to individual recording of these spectra particularly the sensitivity of the least sensitive module, HMBC, is enhanced by designing the homonuclear TOCSY module to allow buildup of magnetization pertinent to HMBC during its execution. Effectively, the sensitivity of the heteronuclear modules is boosted at the expense of the inherently much higher TOCSY sensitivity, thus resulting in a significant saving in spectrometer time.
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http://dx.doi.org/10.1016/j.jmr.2022.107297 | DOI Listing |
Beilstein J Org Chem
October 2023
Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
spp. are a key source of sulfur-containing spiroketal glycosides with potential anti-inflammatory activity. In this study, three new sulfur-containing spiroketals - breynin J (), epibreynin J (), and probreynogenin () - along with four known compounds - probreynin I (), phyllaemblic acid (), breynin B (), and epibreynin B () - were isolated from the roots of .
View Article and Find Full Text PDFThe NMR pulse sequence design strategy of NORD (NO Relaxation Delay) is extended to design of two new three-module experiments, NORD {HMBC}-{HSQC-TOCSY}-{TOCSY} and NORD {HMBC}-{2BOB}-{TOCSY}, each delivering four spectra - HMBC, HSQC, TOCSY, and either HSQC-TOCSY or H2BC. Compared to individual recording of these spectra particularly the sensitivity of the least sensitive module, HMBC, is enhanced by designing the homonuclear TOCSY module to allow buildup of magnetization pertinent to HMBC during its execution. Effectively, the sensitivity of the heteronuclear modules is boosted at the expense of the inherently much higher TOCSY sensitivity, thus resulting in a significant saving in spectrometer time.
View Article and Find Full Text PDFPhytochemistry
December 2016
Department of Environmental Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100, Caserta, Italy.
Three unusual amino-phloroglucinols, named helichrytalicines A-C, along with seventeen known compounds including acetophenones, tremetrone derivatives, low-molecular weight phenols, flavonol glucosides, have been isolated from the medium-polar extract of Helichrysum italicum (Roth) G. Don, a medicinal plant typical of the Mediterranean vegetation. The structures of the compounds have been elucidated based on extensive 2D-NMR spectroscopic analyses, including COSY, TOCSY, HSQC, CIGAR-HMBC, H2BC and HSQC-TOCSY, along with Q-TOF HRMS analysis.
View Article and Find Full Text PDFCarbohydr Res
June 2016
G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 100 Let Vladivostoku Prosp., 159, 690022 Vladivostok, Russia.
The O-specific polysaccharide was isolated from the lipopolysaccharide of type strain Rheinheimera japonica KMM 9513(T) and studied by sugar analysis, Smith degradation, and two-dimensional (1)H and (13)C NMR spectroscopy including (1)H,(1)H-TOCSY, (1)H,(1)H-COSY, (1)H,(1)H-ROESY, (1)H,(13)C-HSQC, (1)H,(13)C-HMBC, (1)H,(13)C-H2BC and (1)H,(13)C-HSQC-TOCSY experiments. The new structure of the O-specific polysaccharide of R. japonica KMM 9513(T) containing N-glycosidic bond was established.
View Article and Find Full Text PDFCarbohydr Res
April 2016
Department of Food and Nutrition Sciences, Graduate School of Dairy Science Research, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
Eight kestose isomers were isolated from sugar beet molasses by carbon-Celite column chromatography and HPLC. GC-FID and GC-MS analyses of methyl derivatives, MALD-TOF-MS measurements and NMR spectra were used to confirm the structural characteristics of the isomers. The (1)H and (13)C NMR signals of each isomer saccharide were assigned using COSY, E-HSQC, HSQC-TOCSY, HMBC and H2BC techniques.
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