• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.84-89
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• 2019

To characterize the molecular structure of BzO-gal synthesized using Escherichia coli ${\beta}$-gal, NMR ($^1H$- and $^{13}C$-) spectroscopy and mass spectrometry of BzO-gal were conducted. $^1H$ NMR spectrum of BzO-gal showed multiple peaks corresponding to the galactosyl group, which is an evidence of galactosylation on BzOH. Five proton peaks around the aromatic region at ${\delta}_H$ 7.43 ~ 7.24 ppm and 2 peaks from ${\delta}_H$ 4.93 and 4.67 ppm were evidence of the presence of the benzyl group. Seven proton peaks at ${\delta}_H$ 4.32 ~ 3.46 ppm showed the presence of a monosaccharide and were indicative of galactosylation on BzOH. $^{13}C$ NMR spectrum also revealed the presence of 11 carbons suggestive of BzO-gal. The mass value (sodium adduct ion of BzO-gal, m/z = 293.0994) from mass spectrometry analysis of BzO-gal, and $^1H$ and $^{13}C$ NMR spectral data were in good agreement with the expecting structure of BzO-gal. We are expecting that through future study it will eventually be able to develop a new additive of low cytotoxicity.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.04a
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• pp.93-99
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• 2011

Proton-NMR spectroscopic method was applied to kinetics study of concentrated sulfuric acid hydrolysis reaction. Xylan was used as model compounds. Without neutralization steps in proton-NMR methods, this analysis method is valid for analysis of xylose, furfural and formic acid in acid hydrolyzates.

• Journal of the Korean Magnetic Resonance Society
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• v.1 no.1
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• pp.45-58
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• 1997

Heteropoly compounds, H3PMo12O40, CsxH3-xPMo12O40, and vanadium containing heteropoly compound were characterized by Solid-state broad line 1H MAS NMR, 31P MAS NMR, and High Speed MAS 51V NMR spectroscopy of quadrupolar nuclei. The effects of calcination, dehydration, and the number of protons on the structure of heteropoly compounds were studied. The results of this study demonstrate that these Solid-state NMR techniques are very useful tools to study heteropoly compounds.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.824-831
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• 2021

1, 2-Octanediol galactoside (OD-gal) has been synthesized from 1, 2-octanediol (OD), as a safer cosmetic preservative, using recombinant Escherichia coli β-galactosidase (β-gal). To confirm the molecular structure of synthesized OD-gal, mass spectrometry and NMR (¹H- and ¹³C-) spectroscopy of OD-gal were carried out. In the reaction mixture, a sodium adduct ion of OD-gal (m/z=331.1732) was identified using mass spectrometry analysis. In addition, ¹H NMR spectrum of OD-gal showed multiple peaks corresponding to the galactosyl group, which is evidence of galactosylation on OD. Downfield proton peaks at δ_H 4.39 ppm and multiple peaks from δ_H 3.98~3.55 ppm were indicative of galactosylation on OD. Up field proton peaks at δ_H 1.52~1.26 ppm and 0.89 ppm showed the presence of CH₂ and CH₃ protons of OD. ¹³C NMR spectrum revealed the presence of 24 carbons suggestive of α- and β-anomers of OD-gal. Among 14 carbon peaks from each anomer, the 4 peaks at δ_C 31.4, 29.0, 22.3, and 13.7 ppm were assigned to be overlapped showing only 24 peaks out of a total of 28 peaks. The mass value from mass spectrometry analysis of OD-gal, and ¹H and ¹³C NMR spectral data were in good agreement with the expecting structure of OD-gal. Finally, we identified a galactose molecule from the hydrolysate of OD-gal using β-gal. We are expecting that through future study it will eventually be able to develop a safe cosmetic preservative.

• Analytical Science and Technology
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• v.9 no.4
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• pp.355-363
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• 1996

The two metabolites, Aaptamine(1) and Demethyl(oxy)aaptamine(2) were isolated from marine Sponge Luffariella sp., collected in October 1992, Manado Bay, Sulawesi in Indonesia showed in vitro activity against KB cancer cell line. Their structures were elucidated by $^1H-$, $^{13}C-NMR$, $^1H-^{13}C$(1 bond) heteronuclear multiple quantum coherence spectroscopy(HMQC), electron ionization mass spectroscopy(EIMS), ultra-violet spectroscopy(UV) and infrared spectroscopy(IR).

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.12-14
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• 1994

p-Fluorophenyl bicyclo[3.2.l]oct-6-en-2-yl cation (3) prepared in $FSO_3H-SO_2-CIF$ solution at -90$^{\circ}$C and examined by fluorine-19 nmr spectroscopy. The nmr data give a clear evidence for the formation of a stabilized ${\pi}$-bridging cation species in superacids. The degree of ${\pi}$delocalization in this cation is found to be inferior to the onset of nonclassical stabilization in 2-norbornenyl cation.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1330-1336
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• 2005

Polyhydroxyalkanoic acid (PHA) inclusion bodies were analyzed in situ by $^{13}C$-nuclear magnetic resonance ($^{13}C$-NMR) spectroscopy. The PHA inclusion bodies studied were composed of poly(3-hydroxybutyrate) or poly(3hydroxybutyrate-co-4-hydroxybutyrate), which was accumulated in Hydrogenophaga pseudoflava, and medium-chain-length PHA (MCL-PHA), which was accumulated in Pseudomonas fluorescens BM07 from octanoic acid or 11-phenoxyundecanoic acid (11-POU). The quantification of the $^{13}C$-NMR signals was conducted against a standard compound, sodium 2,2-dimethyl-2-silapentane-5-sulfonate (DSS). The chemical shift values for the in vivo NMR spectral peaks agreed well with those for the corresponding purified PHA polymers. The intracellular degradation of the PHA inclusions by intracellular PHA depolymerase(s) was monitored by in vivo NMR spectroscopy and analyzed in terms of first-order reaction kinetics. The H. pseudoflava cells were washed for the degradation experiment, transferred to a degradation medium without a carbon source, but containing 1.0 g/l ammonium sulfate, and cultivated at $35^{\circ}C$ for 72 h. The in vivo NMR spectra were obtained at $70^{\circ}C$ for the short-chain-length PHA cells whereas the spectra for the aliphatic and aromatic MCL-PHA cells were obtained at $50^{\circ}C\;and\;80^{\circ}C$, respectively. For the H. pseudoflava cells, the in vivo NMR kinetics analysis of the PHA degradation resulted in a first-order degradation rate constant of 0.075/h ($r^{2}$=0.94) for the initial 24 h of degradation, which was close to the 0.050/h determined when using a gas chromatographic analysis of chloroform extracts of sulfuric acid/methanol reaction mixtures of dried whole cells. Accordingly, it is suggested that in vivo $^{13}C$-NMR spectroscopy is an important tool for studying intracellular PHA degradation in terms of kinetics.

• Journal of Life Science
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• v.10 no.1
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• pp.86-93
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• 2000

Specific molecular recognition of cyclodextrin and aspirin was determined. A stable 1:1 inclusion complex was established in solution. The distinct structure of inclusion complex was elucidated by FT-IR, FAB-MS, UV, 1H NMR, and 13C NMR spectroscopy. Based on the 1H NMR data, a time-averaged conformation of $\alpha$-cyclodextrin exhibited significant catalytic activity toward the hydrolysis of aspirin in alkaline solution.

• Archives of Pharmacal Research
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• v.3 no.1
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• pp.57-64
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• 1980

Carbon-13 NMR spectroscopy(abbreviated CMR) is an extremely powerful strategy for the study of natural organic molecules. The information derivable from CMR is often complementary to that obtianed form proton NMR spectroscopy (PMR). Because of low natural abundance of $^{13}C$ nucleus (1.1%) coupled with low inherent sensitivity relative to $^{1}H$ (about 1/64), CMR experiment is approximately 6000 times less sensitive than PMR. Despite of this, now it is possible to measure CMR of small amount of compound by the development of three significant ingenious techniques, i. e. a) computer time-averaging, b) wide-band (or noise modulated) proton decoupling, and c) pulsed Fourier transform (FT) NMR : For general recognition of CMR, its fundamental aspects of CMR are briefly reviewed.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.283-288
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• 2006

Discrimination of 5 rice cultivars (Sangjubyeo , Dongjinbyeo Simbaekbyeo , Hwamanbyeo , and Simbaek-hetero ) using metabolic profiling was carried out. Whole cell extracts from each cultivar were subjected to $^1H$ NMR spectroscopy. When spectral data were analyzed by principal component analysis, 5 cultivars were clustered into 3 groups: SJ, DJ + SB, and HM + SH. Thecultivars showed great difference in carbohydrate region of $^1H$ NMR spectra, suggesting that qualitative and quantitative differences in carbohydrate compounds play a major role in discrimination of the cultivars. In addition, it was readily possible to determine relative quantification of major carbohydrates including sucrose, glucose, maltose from spectral data of the cultivars. SJ showed 2 to 4 times higher content of maltose than the other rice cultivars. Overall results indicate that metabolic discrimination of rice cultivars using $^1H$ NMR spectroscopy combined by multivariate statistical analysis can be used for rapid discrimination of numerous rice cultivars and simple quantitative analysis system of major carbohydrate compounds in rice grains.