• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.612-617
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• 1993

Some vanadium(III) complexes have been prepared from the reaction of VC$l_3$ with N, P, O-donating ligands and characterized by elemental analysis, $^1$H-NMR infrared and UV-Visible spectroscopy. 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane and 1,1'-bis(diphenylphosphino)ferrocene were chosen as coordinating ligands. Stretching frequency ${\nu}g$(V-Cl) of complexes appears) at 298∼367 cm-1, which show octahedral geometries. Stretching frequency of ${\nu}g$(V-X) (X = N, P, O) indicates that ligands are coordinated to vanadium(III). Stretching frequency ${\nu}g(C{\equiv}N)$ of acetonitrile in these complexes are characteristically shifted to about 70 c$m^{-1}$ higher compared with that of a free ligand (2260 c$m^{-1}$). Bending frequency of $\delta(C{\equiv}N)$ is also shifted to about 60 c$m^{-1}$ higher compared with that of a free ligand (377 c$m^{-1}$). Finally each vanadium(III) complex showed the following formulation; [VC$l_3$(L)$_2$MeCN] or [VC$l_3$(L-L)MeCN].

• Journal of the Korean Chemical Society
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• v.37 no.7
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• pp.655-661
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• 1993

The neutral monomeric compounds $[Mo(NO)_2Cl_2(phen)]$ and $[W(NO)_2Cl_2(phen)]$ (phen= 1,10-phenanthroline) have been prepared by reactions of polymeric compounds $[{Mo(NO)_2Cl_2}n],\;[{W(NO)_2Cl_2}n]$ with chelate ligands. Additions of one equivalent of silver(I) perchlorate to these cis-dinitrosyl compounds in acetone solution produce $[Mo(NO)_2(phen)(S)Cl][ClO_4]\;and\;[W(NO)_2(phen)(S)Cl][ClO_4]$ (S = acetone). The homo- and hetero-dinuclear complexes, $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][ClO_4]_2$ (M = Mo, W) and $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][C1O_4]_2$ (M = Mo, M' = W) have been prepared by these monocationic complexes with pyrazine ligand respectively. These complexes characterized by elemental analysis, $1^H-\;and\;^{13}C-NMR$, infrared, and UV-visible spectroscopy are reported. The spectral data indicate that homo- and hetero-dinuclear complexes were symmetrical structures of $C_{2v}$.

• Korean Journal of Microbiology
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• v.32 no.4
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• pp.315-321
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• 1994

Glyoxalase I was purified 2,294-fold from Pleurotus ostreatus by S-hexylglutathione affinity chromatography, Sephadex G-150 gel filtration chromatography and DEAE-sepharose A-50 CL-6B ion exchange chromatography with an overall yield of 21.7%. The molecular mass determined by gel filtration was found to be approx. 34 kDa. SDS-PAGE revealed that the enzyme consists of two identical subunits with a molecular mass of approx. 17 kDa. The K sub(m) values of this enzyme for methylglyoxal and phenylglyoxal were 0.39 mM and 0.22 mM, respectively. And this enzyme had a strong affinity for L-xylosone and hydroxypyruvaldehyde. The enzyme showed its optimal activity at pH 6.5-7.5 and at $40^{\circ}C$. $^1H$-NMR spectroscopic analysis of enzymic reaction showed that this enzyme catalyzes intramolecular proton transfer.

• Korean Journal of Environmental Agriculture
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• v.34 no.1
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• pp.57-63
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• 2015

BACKGROUND: Momordica charantia (MC) have been used in various parts of the world to treat diabetes. Despite the highest effects of phytochemicals than any other part of the plant, the main components of seed of MC grown in Korea and their properties have not been studied extensively. METHODS AND RESULTS: The seeds of MC were extracted into five different polarity solvents: 30%, 50%, 70%, 95% ethanol and distilled water. The 95% ethanol extract showed the most potent inhibition ($IC_{50}=88.7{\mu}g/mL$) against ${\alpha}$-glucosidase. To investigate the compounds responsible for this effect, activity guided fractionation of MC seeds by chromatography yielded two phytochemicals which were confirmed as vicine (1) and ${\alpha}$-eleostearic acid (2) based on their NMR and ESI-MS spectroscopic data. Among them, ${\alpha}$-eleostearic acid (2) possessed potent ${\alpha}$-glucosidase inhibitory activities with $IC_{50}$ values from $32.4{\mu}g/mL$. CONCLUSION: Collectively, the results from this present study strongly suggest that both extract and ${\alpha}$-eleostearic acid (2) have potent ${\alpha}$-glucosidase inhibitory activity. Furthermore, ${\alpha}$-eleostearic acid (2) as the most active ${\alpha}$-glucosidase inhibitor was proven to be present in high quantities in the MC seeds by a HPLC chromatogram.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.626-632
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• 2013

In the course of a developing screening method for resistant radish to Fusarium oxysporum f. sp. raphani, we found that the fungus produces phytotoxic compound against Raphanus sativus. The culture filtrate of F. oxysporum f. sp. raphani KR1 represented the strongest phytotoxicity when the fungus was incubated in the malt extract broth with 150 rpm at $25^{\circ}C$ for 14 days. Under bioassay-guided purification, we isolated a substance from liquid culture of F. oxysporum f. sp. raphani KR1, with phytotoxic effect against R. sativus. The compound was identified as fusaric acid by mass and nuclear magnetic resonance spectral analyses. Phytotoxicity of the compound against cruciferous vegetable crops, including radish, cabbage, and broccoli, was investigated. Fusaric acid represented phytotoxicity on radish seedlings by concentration dependant manner. And the phytotoxin demonstrated strong phytotoxicity on the resistant cultivars as well as susceptible cultivars of radish to F. oxysporum f. sp. raphani. In addition, fusaric acid isolated from the fungus also showed a potent phytotoxic efficacy against non-host Brassicaceae crops of the fungus such as cabbage and broccoli. The results demonstrate that fusaric acid produced by F. oxysporum f. sp. raphani is non-host-specific toxin and for screening of resistant radish to the fungal pathogen, spore suspension of the fungus without the phytotoxin has to be used.

• Korean Journal of Medicinal Crop Science
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• v.27 no.1
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• pp.24-29
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• 2019

Background: Camellia sinensis L.(CS) is a perennial evergreen species of plant whose leaves are used to produce tea. In this plant species, the parts used are the leaves, sub-branch parts are thrown out. Methods and Results: Ethanol extract of sub-branch parts was used for isolation of major compounds by column chromatography. Structures were identified as caffeine (1), (-)-epicatechin (2) and (-)-epicatechin gallate (3) by interpretation of spectroscopic analysis, including $^1H$- and $^{13}C$-NMR. High-performance liquid chromatography (HPLC) method was used to compare the quantitative level of marker compounds in various extraction solvents of sub-branch parts of CS. The content of caffeine, (-)-epicatechin, and (-)-epicatechin gallate in 30% ethanol extract showed higher value with $3.28{\pm}0.57mg/g$, $5.53{\pm}0.88mg/g$, and $1.29{\pm}0.24mg/g$, respectively. Conclusions: These results indicated that not only leaves parts but also sub-branch, could be a good source for the functional material and pharmaceutical industry.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.581-587
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• 2022

The leather industry generates a large amount of hazardous leather waste of various types every year. Among them, shaving scrap is difficult to recycle because it contains chromium ions. Many studies in recent years have shown that shaving scraps can be processed into various types of valuable products, such as adsorbent, filler, and poultry feed. In this study, collagen peptides were extracted from shaving scraps and structurally modified to be developed as new materials with improved physicochemical properties. First, the chromium ions contained in the shaving scraps were removed using a sodium hydroxide solution, and purified through concentration and low-temperature crystallization. The purified collagen peptide was used to prepare the powder using a spray dryer. The extracted collagen peptides were structurally modified by introducing double bonds by reacting with methacrylic anhydride (MAA), and the product was confirmed by ¹H NMR spectroscopy. Next, a copolymer was prepared by redox polymerization of the modified collagen peptide (MCP) and 2-ethylhexyl acrylate (2-EHA). The structure of the copolymer was qualitatively confirmed by FT-IR. In conclusion, this study confirmed that collagen peptides can be extracted from shaving scrap and converted into new eco-friendly materials through certain treatments.

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.26-35
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• 2001

In order to search potent antifungal substances from domestic plants, 40 plants cultivated in Korea were collected. After extracting with methanol (MeOH) and concentrating to dryness, the MeOH extracts were screened for in vivo antifungal activity against six plant diseases at a concentration of $2000{\mu}g/mL$. Fourteen extracts showed disease-controlling activity more than 90% against at least one of the 6 plant diseases tested; eight, seven, and three extracts controlled more than 90% the development of rice blast, tomato late blight, and wheat leaf rust, respectively. However, none of the extracts exhibited in vivo antifungal activity more than 90% against rice sheath blight, tomato gray mold, and barley powdery mildew. From the MeOH extracts of Angelica gigas and A. dahurica showing potent controlling activity against rice blast, 1 and 2 antifungal substances, respectively, were isolated by solvent partitioning and column chromatography. The three compounds were identified to be coumarins, namely, decursin, imperatorin, and isoimperatorin, by mass spectrometry and NMR spectroscopy. They were examined for in vitro and in vivo antifungal activities together with umbelliferone (7-bydroxycournarin) and scopoletin (6-methoxy-7-hydroxycoumarin) containing a free hydroxyl group at position 7 to investigate the structure-activity relationship. In vitro, most of 50% growth inhibitory concentrations ($IC_{50}$) were over $200{\mu}g/mL$, indicating that they have relatively weak antifungal activity. The antifungal activity of decursin and scopoletin, containing cyclic alkoxy groups instead of free hydroxyl group at position 7, was stronger than umbelliferone and scopoletin. Especially, decursin and imperatorin showed potent antifungal activities against Pythium ultimum and Magnaporthe grisea, respectively, with $IC_{50}$ values less than $25{\mu}g/mL$. In vivo, decursin and imperatorin showed potent antifungal activity against rice blast, whereas other coumarins hardly controlled the development of 6 plant diseases tested. These results suggest that the antifungal activity of 7-hydroxycoumarin derivative is substantially increased when the hydroxyl group at position 7 is protected by a stable cyclic alkoxy grouping.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.31-38
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• 2004

An endophytic bacterial strain EB215 that was isolated from cucumber (Cucumis sativus) roots displayed a potent in vivo antifungal activity against Colletotrichum species. The strain was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, and 16S rDNA gene sequence. Optimal medium and incubation period for the production of antifungal substances by B. cepacia EB215 were nutrient broth (NB) and 3 days, respectively. An antifungal substance was isolated from the NB cultures of B. cepacia EB215 strain by centrifugation, n-hexane partitioning, silica gel column chromatography, preparative TLC, and in vitro bioassay. Its chemical structure was determined to be pyrrolnitrin by mass and NMR spectral analyses. Pyrrolnitrin showed potent disease control efficacy of more than 90% against pepper anthracnose (Colletotrichum coccodes), cucumber anthracnose (Colletotrichum orbiculare), rice blast (Magnaporthe grisea) and rice sheath blight (Corticium sasaki) even at a low concentration of $11.1\;{\mu}g/ml$. In addition, it effectively controlled the development of tomato gray mold (Botrytis cinerea) and wheat leaf rust (Puccinia recondita) at concentrations over $33.3\;{\mu}g/ml$. However, it had no antifungal activity against Phytophthora infestans on tomato plants. Further studies on the development of microbial fungicide using B. cepacia EB215 are in progress.

• Progress in Medical Physics
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• v.21 no.1
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• pp.35-41
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• 2010

The purpose of this study is to quantitate regional neurochemical profile of regional normal adult mice brain and assess regional metabolic differences by using ex vivo $^1H$ high-resolution magic angle spinning nuclear magnetic resonance spectroscopy ($^1H$ HR-MAS NMRS). The animals were matched in sex and age. The collected brain tissue included frontal cortex, temporal cortex, thalamus, and hippocampus. Quantitative 1D spectra were acquired on 40 samples with the CPMG pulse sequence (8 kHz spectral window, TR/TE = 5500/2.2 ms, NEX = 128, scan time: 17 min 20 sec). The mass of brain tissue and $D_2O$+TSP solvent were 8~14 mg and 7~13 mg. A total of 16 metabolites were quantified as follow: Acet, NAA, NAAG, tCr, Cr, tCho, Cho, GPC + PC, mIns, Lac, GABA, Glu, Gln, Tau and Ala. As a results, Acet, Cho, NAA, NAAG and mIns were showed significantly different aspects on frontal cortex, hippocampus, temporal cortex and thalamus respectively. The present study demonstrated that absolute metabolite concentrations were significantly different among four brain regions of adult mice. Our finding might be helpful to investigate brain metabolism of neuro-disease in animal model.