• Journal of Ginseng Research
• /
• v.19 no.1
• /
• pp.45-50
• /
• 1995

(20S)- and (20R)-protopanaxadiol were prepared from crude ginseng saponin by chemical treatment. The $^{1}H$- and $^{13}C$-NMR signals of these compounds were fully assigned by various NMR techniques such as DEPT, 1H-1H COSY, HMQC, HMBC and NOESY.

• Journal of Ginseng Research
• /
• v.20 no.1
• /
• pp.111-112
• /
• 1996

The chemical shifts of C-21 and C-23 in the $^{13}C$-NMR for (20R)-protopanaxatriol, (20R)-ginsenoside $Rh_1$ and (20R)-ginsenoside $Rg_3$ were revised by employing some extensive 2D-NMR techniques.

• Applied Biological Chemistry
• /
• v.38 no.2
• /
• pp.184-189
• /
• 1995

(20S)- and (20R)-Ginsenoside $Rh_2$ were prepared from crude ginseng saponin by chemical treatments. The $^1H-$ and $^{13}C-NMR$ signals of these compounds were fully assigned by various NMR techniques such as DEPT, $^1H-^1H$ COSY, HMQC, HMBC and NOESY.

• Journal of the Korean Magnetic Resonance Society
• /
• v.25 no.2
• /
• pp.12-16
• /
• 2021

Daphnia magna is used as target organism for environmental metabolomics. The metabolome of D. magna was studied with NMR spectroscopy. Most studies used the extract of D. magna, but the reproducibility cannot be obtained using extracted sample. In this study, lyophilized D. magna samples were analyzed with two different ¹H NMR techniques, HR-MAS on intact tissues and solution NMR on extracted tissues. Samples were measured three times using 600 MHz NMR spectrometer. Metabolite extraction required more than twice as many D. magna, but the metabolite intensity was lower in solution NMR. In the spectra of HR-MAS NMR, the lipid signal was observed, but they did not interfere with metabolite profiling. We also confirmed the effect of swelling time on signal intensities of metabolites in HR-MAS NMR, and the results suggest that appropriate swelling should be used in lyophilized D. magna to improve the accuracy of metabolite profiles.

• Journal of the Korean Magnetic Resonance Society
• /
• v.5 no.2
• /
• pp.91-98
• /
• 2001

The $^1$H and $^{13}$ C NMR spectra of chivosazole F from Sorangium cellulosum were completely assigned by a combination of ID and 2D NMR techniques. The configurations of double bonds were confirmed from the ROESY spectra. The stereochemistry at asymmetric carboncenters was partially assigned on the basis of the results of NOE analysis.

• Journal of the Korean Magnetic Resonance Society
• /
• v.27 no.2
• /
• pp.10-15
• /
• 2023

The Strain-Promoted Azide-Alkyne Cycloaddition (SPAAC) is a powerful method for synthesizing triazoles, even under physiological conditions, without a copper catalyst. This technique provides an efficient means for everyone to synthesize complex triazole derivatives rapidly. In order to investigate the configuration of triazole derivatives using bicyclo[6.1.0.]-nonyne (BCN) and chiral azide, it is necessary to employ the 2D NMR. Both 1D and 2D NMR (COSY, HSQC, ¹⁵N HMBC) are used to analyze the complex triazole product containing cyclooctyne, a diastereomeric product. The stereometric difference of the proton bonded to the same carbon is determined through the HSQC assignment. The intriguing splitting pattern of carbon resonances also reveals their diastereomeric configuration and will aid in further research based on physiological knowledge.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.3
• /
• pp.339-344
• /
• 2003

The conformation of synthetic oligosaccharide can be elucidated by employing molecular modeling and highfield proton NMR (nuclear magnetic resonance) spectroscopy. Information with respect to the composition and configuration of saccharide residues and the sequence and linkage positions of the oligosaccharide can be obtained by employing a variety of one- and two-dimensional NMR techniques and molecular modeling. These techniques are also useful in establishing the solution conformation of the oligosaccharide moiety. This study is focused on the elucidation of linkage positions of synthetic trisaccharides, Gal(β1-4)Glc(β1-3)Glc, Gal(β1-4)Glc(β1-4)Glc and Gal(β1-4)Glc(β1-6)Glc.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.3
• /
• pp.384-386
• /
• 1998

• YAKHAK HOEJI
• /
• v.39 no.3
• /
• pp.268-275
• /
• 1995

A novel polyacetylene was isolated from Cirsium spp., as well as five known ones, and its chemical structure was determined as heptadeca-1-en-11.13-diyne-8R, 9S, 10R-triol(1) on the basis of spectral data and chemical reactions. $^{1}$H-and $^{13}$C-NMR data of these polyacetylenes were completely assigned by the appfication of 2D-NMR techniques.

• Journal of the Korean Magnetic Resonance Society
• /
• v.4 no.2
• /
• pp.125-132
• /
• 2000

The detailed $^1$H and $^{13}$ C NMR assignments of a novel sucrose isovaleryl ester isolated from the seed of Euphorbia Lathyris L., were achieved by one-and two-dimensional techniques. The new sucrose ester was characterized as an $\alpha$-D-glucopyranoside, 3,4,6-tris-O-(3-methyl-1-oxobutyl)-$\beta$-D-fructofuranosyl, 2,6-bis(3-methylbutanoate); sucrose 4,7,8,11,12-pentaisovalerate by MS and NMR experiments.