• The Journal of the Petrological Society of Korea
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• v.3 no.1
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• pp.34-40
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• 1994

High pressure X-ray diffraction study was carried out on a graphite to investigate its compressibility as well as any possible phase transition to the hexagonal diamond structure at room temperature. Energy dispersive X-ray diffraction method was introduced using a Mao-Bell type diamond anvil cell with Synchrotron Radiation. Polycrystalline sodium chloride was compressed together with graphite for the high pressure determinations. Because of the poor resolution of the X-ray diffraction pattern of graphite, its compressibility was estimated to be almost same as that of NaCl by graphite (002) X-ray diffraction peak only. An observation of any new peak from a possible hexagonal diamond phase seems very unplausible for its definite identification based on the present data. Alternative approaches such as an Wiggler Radiation source as well as a Large Volume high pressure apparatus will be necessary for the detailed studies on a graphite in future.

• Journal of the Korean Chemical Society
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• v.63 no.4
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• pp.237-245
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• 2019

Hydrogen bihalide anions, $XHX^-$ (X = F, Cl, and Br) have been studied by high level ab initio methods to determine the molecular structure, vibrational frequencies, and energetics of the anions. All bihalide anions are found to be of linear and symmetric structures, and the calculated bond lengths are consistent with experimental data. The harmonic frequencies exhibit large deviations from the experimental frequencies, suggesting the vibrations of these anions are very anharmonic. Two different approaches, the VSCF and VPT2 methods, are employed to calculate the anharmonic frequencies, and the results are compared with the experimental frequencies. While the ${\nu}_1$ and ${\nu}_2$ frequencies are in reasonable agreement with the experimental values, the ${\nu}_3$ and ${\nu}_1+{\nu}_3$ frequencies still exhibit large deviations. The hydrogen-bond energies and enthalpies are calculated at various levels including the W1BD and G4 composite methods. The hydrogen-bond enthalpies calculated are in good agreement with the experimental values.

• Biomedical Science Letters
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• v.27 no.3
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• pp.154-160
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• 2021

Codonopsis lanceolata has numerous chemical constituents that includes polyphenols, saponins, tannins, triterpene, alkaloids, and steroids. The extract of C. lanceolata was partitioned with Haxane, CH₂Cl₂, EtOAc, n-BuOH and MeOH. The determination of structure for lancemaside G, lancemaside B, lancemaside A were based on physicochemical and HPLC chromatogram data, including NMR and HR-MS. In addition, tangshenoside I and lobetyolin were identified in the material separation process for the extract of C. lanceolata, and content analysis was performed using HPLC. The compounds were confirmed as lancemaside G, lancemaside B, lancemaside A, tangshenoside I, and lobetyolin.

• Bulletin of the Korean Chemical Society
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• v.11 no.3
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• pp.251-253
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• 1990

L-Alanine(L-ala) and S-methyl-L-cysteine(L-mcy) cobalt(III) complexes of a flexible $N_2O_2$-type tetradentate ligand ethylenediamine-N,N'-di- -butyric acid(eddb), s-cis-[Co(eddb)(L-ala)] and s-cis-[Co(eddb)(L-mcy), have been prepared via the substitution reactions of the s-cis-$[Co(eddb)Cl_2]$-complex with, respectively, L-alanine and S-methyl-L-cysteine. Both L-alanine and S-methyl-L-cysteine are found to coordinate to the cobalt(III) ion via the nitrogen and oxygen donor atoms to give the meridional s-cis isomer. Electronic absorption, ir and pmr spectra are used to characterize the complexes obtained in this work along with elemental analysis data.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.261.1-261.1
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• 2003

The EtOAc and CH$_2$Cl$_2$ soluble fractions from the fruit body of Ganoderma applanatum showed strong aldose reductase inhibitory activity. Nine compounds were isolated from both fractions. They were identified by spectral data as D-mannitol (1), 2-methoxyfatty acid (2), cerebrosides [(2S,3R,4E,8E)-1-O-${\beta}$-D-glucopyranosyl-3-hydroxy-2-[(R)-2'-hydroxypalmitoyl]amino-9-methyl-4,8-octadecadiene] (3), daucosterol (4), 2,5-dihydroxybenzoic acid (5), protocatechualdehyde (6), 5-dihydroergosterol (7), ergosterol peroxide (8), and cerevisterol (9). (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.67.2-67.2
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• 2003

Four new lanostane-type triterpenes were isolated from CH$_2$Cl$_2$ fraction of Ganoderma applanatum (Polyporaceae). There structures were determined as (20S)-3${\beta}$, 7${\beta}$, 20,23ζ-tetrahydroxy-1l,15-dioxolanosta-8-en-26-oic acid, (20S)-7${\beta}$,20,23ζ- trihydroxy-3,1l,15-trioxolanosta-8-en-26-oic acid, 7${\beta}$,23ζ-dihydroxy-3,11,15- trioxolanosta-8,20E(22)-dien-26-oic acid, and 7${\beta}$-hydroxy-3, 11,15,23-tetraoxolanosta-8,20E(22)-dien-26-oic acid methyl ester on the basis of spectral data.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.190.4-191
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• 2003

This study was carried out to examine the constituents of Amorpha fruticosa (Leguminosae), a shrub originated from North Africa. Dried and ground fruit of A. fruticosa were extracted with methanol and then concentrated to give the crude extracts. The crude extracts was successively fractioned with organic sovents, such as n-hexane, CH$_2$Cl$_2$ and EtOAc. Seven compounds were isolated from the fruits of A. fruticosa. On the basis of spectrosopic data, the structures of these compounds were determined as: kaempferol 7-O-${\alpha}$-L-rhamnopyranoside (I), methyl 3,4,5- trihydroxybenzoate (methyl gallate, II), tephrosin (III), dalbinol (IV), gallic acid (V), 2",4",5",7-tetramethoxyisofavone (Ⅵ) and Dalbinol 2"-O-${\beta}$-D-Glucopyranoside (Ⅶ) respectively. (omitted)

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.337-342
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• 2022

Calf diarrhea is a major health concern in the livestock industry that requires accurate analysis for appropriate treatment. Dehydration and electrolyte imbalance are the most significant consequences of diarrhea in calves. Until now, the reference values of blood analysis of Hanwoo neonatal calves have not been well known. Recently, portable blood analyzers have made it possible to immediately analyze blood in the farm and provide suitable treatment for the patients. We analyzed electrolytes, blood urea nitrogen (BUN) and glucose in the blood of 179 Hanwoo neonatal calves, including 79 with diarrhea. These 179 calves were divided into 3 groups based on their age. Values of sodium (Na⁺ ) and glucose were significantly lower in diarrheic calves (1~30 days), while potassium (K⁺ ) and chloride (Cl^- ) values were higher in diarrheic calves (1~30 days). BUN values, which are closely related to dehydration due to diarrhea, increased in diarrheic calves of all ages. Therefore, these data can be used as reference values for blood analysis and treatment of healthy or diarrheic Hanwoo neonatal calves within 30 days of age.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.121-122
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• 2023

This study investigates the anti-corrosion properties of two eco-friendly pyridinium ionic liquids; 4DMN and 4DMP, in a 3.5% NaCl solution. Utilizing weight loss tests, EIS, PDP, quantum chemical calculations, and molecular dynamics simulations, the study demonstrates concentration-dependent inhibition efficiencies of 94% and 92% for 4DMN and 4DMP, respectively. The compounds modulate both anodic and cathodic reactions without altering the corrosion mechanism. EIS data suggest that a protective layer forms, supported by FE-SEM and AFM surface analyses, which reveal improved morphology and reduced roughness. Computational validations corroborate these empirical findings, highlighting the feasibility of these ionic liquids for effective, sustainable corrosion mitigation.

• Journal of the Korean Magnetic Resonance Society
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• v.28 no.3
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• pp.10-14
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• 2024

Caveolin3, mainly expressed in muscle tissue types, is a structural scaffolding protein of caveolae which are microdomains of plasma membrane. To elucidate the relationship between structure and function, several studies on the structure of caveolins using NMR have been reported. Because the ionic strength can affect the electrostatic-driven association of proteins with ligand and protein structure, the effect of salt in the structural studies has to be considered. In this work, we observed that the chemical shifts of Cav3 in the LPPG detergent change depending on salt concentration. The R2 values also show salt concentration-dependent changes. Specifically, in the N-terminal region where conformational changes and various interactions occur, the R2 values decrease. Interestingly, the R2 values of residues expected to be located in the LPPG detergent are also influenced by the salt concentration. This work suggests that the concentration of NaCl can affect interpretation of NMR data from membrane proteins.