• Preventive Nutrition and Food Science
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• v.18 no.3
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• pp.218-221
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• 2013

Korean cabbage, a member of the Brassicaceae family which also includes cauliflower, mustard, radish, and turnip plants, is a crucial leafy vegetable crop. Korean cabbage is harvested after completion of the leaf heading process and is often prepared for use in "baechu kimchi", a traditional Korean food. Many of the components in Korean cabbage are essential for proper human nutrition; these components can be divided into two groups: primary metabolites, which include carbohydrates, amino acids, fatty acids, and organic acids, and secondary metabolites such as flavonoids, carotenoids, sterols, phenolic acids, alkaloids, and glucosinolates (GSLs). Using gas chromatography-mass spectrometry, this study examined the variety of volatile compounds (including isothiocyanates) contained in Korean cabbage and its seed, which resulted in the identification of 16 and 12 volatile compounds, respectively. The primary volatile compound found in the cabbage was ethyl linoleolate (~23%), while 4,5-epithiovaleronitrile (~46%) was the primary volatile component in the seed.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.315-318
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• 1995

Sulfanilic acid (4-aminobenzenesulfonic acid) alone is normally not permeant in bacteria but can be readily delivered via the microbial dipeptide transport system. A dipeptidyl derivative of this compound, L-phenylalanyl-L-2-sulfanilylglycine (PSG), prepared by attachment of its primary amino group to the phenylalanyl $\alpha$-glycine moiety, appeared to have a Km of 0.125 mM and a Vmax of 1.9 nmoles/ml/min ($A_{660}$, 1.0) in Escherichia coli. From competitive spectrophotometric analysis, it was found that the type of amino acids in both of the N- and C-terminals affected the kinetic power of dipeptides. The growth inhibitory effect of PSG was over 7 times more potent than that of the sulfanilic acid against E. coli, suggesting that this potential inhibition was presumably due to the increased hydrophobic nature of the sulfanilyl dipeptide.

• Journal of Applied Biological Chemistry
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• v.49 no.3
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• pp.110-113
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• 2006

Prolyl endopeptidase (PEP, EC 3.4.21.26, also referred to as prolyl oligopeptidase) degrades proline containing, biologically active neuropeptides such as vasopressin, substance P and thyrotropin-releasing hormone by cleaving peptide bonds on carboxyl side of prolyl residue within neuropeptides of less than 30 amino acids. Evaluation of PEP levels in postmortem brains of Alzheimer's disease patients revealed significant increases in PEP activity. Therefore, a specific PEP inhibitor can be a good candidate of drug against memory loss. Upon our examination for PEP inhibitory activity from micronutrients, ascorbic acid (vitamin C) showed small but significant PEP inhibition (13% PEP inhibition at $8{\mu}g{\cdot}ml^{-1}$). Palmitic acid showed almost no PEP inhibition. However, 6-O-palmitoyl ascorbic acid ($\underline{1}$) showed 70% PEP inhibition at $8{\mu}g{\cdot}ml^{-1}$ indicating that hydrophobic portion of the compound $\underline{1}$ may facilitate the inhibitory effect. $IC_{50}$ value of compound $\underline{1}$ was $12.6{\pm}0.2{\mu}M$. The primary and secondary Lineweaver Burk and Dixon plots for compound $\underline{1}$ indicated that it is a non-competitive inhibitor with inhibition constant (Ki) value of $23.7{\mu}M$.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.96-104
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• 2018

Stable isotope approach for aquatic ecology and environmental sciences has been introduced as very useful technique since 1980s and also has been applied to investigate various issues in aquatic ecology and environmental study last 10 years in Korea. Especially carbon and nitrogen isotope ratios have been mainly used to understand food web energy flow and ecosystem structure. In addition, nitrogen isotope ratio has been applied for nitrogen cycle and source identification as well as biomagnification studies. However, large temporal or spatial variations of nitrogen isotope ratio of primary producer have been found in many aquatic environments, and it is regarded as the critical problems to determine trophic level of aquatic animals. Recently, the compound specific isotope analysis of nitrogen within individual amino acids has been developed as an alternative method for trophic ecology. This article introduces the progress history of stable isotope application in aquatic ecology and environmental sciences, and also suggests new direction based on future prospects in stable isotope ecology and environmental study.

• Fisheries and Aquatic Sciences
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• v.24 no.4
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• pp.163-170
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• 2021

Peptides are naturally occurring biological molecules that are found in all living organisms. These biologically active peptides play a key role in various biological processes. The aim of this study is the extraction and the purification of bioactive materials that induce relaxation of an apical muscle from the pyloric caeca of Patiria pectinifera. The acidified pyloric caeca extract was partially separated by the solid phase extraction using a stepwise gradient on Sep-Pak C18 cartridge. Among the fractions, materials eluted with 60% methanol/0.1% trifluoroacetic acid was put a thorough of a series of high performance liquid chromatography (HPLC) steps to isolate a neuropeptide with relaxation activity. The purified compound was eluted at 28% acetonitrile in 0.1% trifluoroacetic acid with retention time of 25.8 min on the CAPCELL-PAK C18 reversed-phase column. To determine the molecular weight and the amino acid sequence of the purified peptide, LC-MS and Edman degradation method were used, respectively. The primary structure of the peptide was determined to be FGMGGAYDPLSAGFTD which corresponded to the amino acid sequence of a starfish myorelaxant peptide (SMP) isotype (SMPb) found in the cDNA sequence encoding SMPa and its isotypes. In this study, a muscle relaxant neuropeptide (SMPb) has been isolated from pyloric caeca of starfish P. pectinifera. This is the first report of SMPb isolation on the protein level from P. pectinifera.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.561-566
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• 2009

Chloroacylation of 3-amino-2-phenylpyrazole-4-carboxamide (2) using chloroacetyl-(propionyl) chloride affording 6-chloromethyl(ethyl)-1-phenylpyrazolo[3,4-d]pyrimidin-4[5H]-one (3) or (6). Chlorine atom in compound (3) or (6) underwent nucleophilic substitution reaction with primary or secondary amines to give 6-alkyl(aryl)aminomethyl(ethyl)-1-phenylpyrazolo[3,4-d]pyrimidin-4[5H]-one (4a-g,7a-f). When arylaminomethyl( ethyl)pyrazolopyrimidine was treated with formaline (30%) solution in ethanol, underwent Mannich reaction to afford imidazopyrazolopyrimidines (5a-e) and pyrazolopyrimidopyrimidines (8a-e). Chloromethylpyrimidine derivative 3 was converted into the corresponding mercaptomethylpyrazolopyrimidene 9, Which cyclized using bromomalononitrile or phenacyl bromide into pyrazolopyrimidothiazine 11,12.

• Bulletin of the Korean Chemical Society
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• v.11 no.2
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• pp.140-143
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• 1990

Ethanolic tetra carbonylhydridoferrate solution combined with dialdehyde (no of carbon; 4,5,6) is very efficient for the selective transformation of amino group into N-heterocyclic compound. However, a large variety of both aliphatic and aromatic amines react with the ferrate-pimelaldehyde at room temperature under an atmospheric pressure of carbon monoxide to give the corresponding N-(cyclohexylmethyl)-N-alkyiamine derivatives in moderate yields instead of the corresponding N-substituted perhydroazocine derivatives.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.242-247
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• 2011

A greening phenomenon has been observed in some plant foods such as chestnut, sweet potato, burdock, and others during processing. The formation of the pigments was postulated as reactions of primary amino compounds with chi orogenic acid or caffeic acid ester, yielding acridine derivatives. Acridine derivatives have been regarded as mutagenetic agents. For the reason, the bacterial reverse mutation test was carried out to evaluate the genotoxicity of green pigment using Salmonella typhimurium TA98 and TA100. Alanine, arginine, aspartic acid, glycine, lysine, and phenylalanine were reacted repectively with chlorogenic acid to synthesize model compound. Green pigment was extracted from sweet potato. Maximum concentration of 2 and 50 mg/plate was tested for the synthetic green pigments and extracted green pigment respectively, taking bacterial survival, solubility, and color intensity into consideration. There was no signigicant increase in the reverse mutation either with or without S9 activation system by any test material. Though further studies with other genotoxicity test system are necessary, both synthetic and sweet potato green pigments seemed not to cause mutation despite the acridine moiety in their structures.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.409-416
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• 2012

The amount of cellular components including soluble sugars, amino acids, organic acids and glucosinolates (GLS) was investigated during radish root processing to develop a radish beverage. The radish root was divided into two parts, white and green tissue, and processed separately by extracting the juice from the fresh tissue and from the boiled tissue to compare differences in the components content among the preparations. The overall palatability of both the fresh and boiled extracts from the green part of the radish was higher than that of the same extracts from the white part. The sweetness of extract by boiling increased and its pungency decreased, thereby the palatability increased by being compared to the fresh radish extract. The sweetness was affected by sucrose not by glucose or fructose of monosaccharides by showing different sucrose contents according to treatment comparing palatability. Malic acid was identified as primary organic acid, and the content was higher in both the fresh and boiled extracts from the white part than in the extracts from the green part of the radish. The fresh extract from the green part of the radish contained more essential amino acids, such as threonine and valine, and more hydrophilic amino acids including glutamic acid, aspartic acid, and arginine than those of the fresh extract from the white part, suggesting the green fresh part is more palatable than the white fresh part. The main sulfur compound was ethylthiocyanate in radish, and others were butyl isothiocyanate, dimethyl-disulfide, and 4-methylthio-3-butylisothiocyanate. The four GLS were detected much more in the fresh green and fresh white parts of the radish because they evaporated during boiling. The contents of the four sulfur compounds were higher in the white fresh part than in the green fresh part, which is likely the reason the pungency was higher and the palatability was lower in the white fresh part than in the green fresh part of the radish. The ascorbic acid content was higher in the fresh extract compared to the boiled extracts from both the green and white parts. Taken together, these findings indicate that fresh radish extract is superior to obtain in terms of retaining desirable nutritional and functional components for health.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.594-602
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• 2011

The effect of ${\alpha}$-, ${\beta}$- and ${\gamma}$-picolines on the stereochemistry of the coordination compounds of lanthanide(III) nitrates derived from 4[N-(furfural)amino]antipyrine semicarbazone (FFAAPS) has been studied. The general composition of the present coordination compounds is [Ln(FFAAPS)$(NO_3)_3$Pic] (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy or Ho and Pic=${\alpha}$-, ${\beta}$- or ${\gamma}$-picolines). All these coordination compounds have been characterized by elemental analyses, molecular weight, molar conductance, magnetic susceptibility, infrared and electronic spectra. The infrared studies suggest that the FFAAPS behaves as a neutral tridentate ligand with N, N, O donor while ${\alpha}$-, ${\beta}$- or ${\gamma}$-picoline is coordinated to the lanthanide(III) ions via heterocyclic N-atom. Nitrates are bicovalently bonded in these compounds. From the electronic spectral data, nephelauxetic effect (${\beta}$), covalence factor ($b^{1/2}$), Sinha parameter (${\delta}%$) and the covalence angular overlap parameter (${\eta}$) have been calculated. Thermal stabilities of these complexes have been studied by thermogravimetric analysis. The coordination number of lanthanide(III) ions in the present compound is found to be ten. The antibacterial studies screening of the primary ligand FFAAPS and the complexes showed that the present complexes have moderate antibacterial activities.