• Analytical Science and Technology
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• v.13 no.3
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• pp.385-393
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• 2000

A gas chromatography-mass spectrometric (GC/MS) procedure for the determination of amineptine (dihydro-10, 11-dibenzo[a, d] cycloheptenyl-5-amino-7-heptanoic acid) and its main metabolites in human urine was described. Amineptine has been known to be extensively metabolized by the ${\beta}$-oxidation of the heptanoic side chain with formation of pentanoic side chain metabolite ($C_5$-metabolite), and lactamizarion by internal dehydration of (${\beta}$-oxidized metabolite (${\delta}$-lactam). The detection of these compounds was based on acid hydrolysis, liquid-liquid extraction and trimethylsilylated derivatization of the carboxylic acid group. For the determination of amineptine and its metabolites in biological fluids, selected ions at the m/ 192, molecular ion and one of the characteristic ions were monitored by GC/MS. On the excretion study of amineptine in human urine, 70-90% of amineptine, ${\delta}$-lactam, and $C_5$-metabolite were found to be excreted within 4 hours and their excretion completed within 20 hours.

• Culinary science and hospitality research
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• v.22 no.6
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• pp.71-77
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• 2016

To determine the nutritional value of domestic tomatoes, the levels of amino acids, amino acid metabolites, and the bioactive compound ${\gamma}-aminobutyric-acid$ (GABA) were analyzed in three domestic tomato varieties (Rafito, Momotaro, and Medison). Eighteen free amino acids were found, and total free amino acid content was 3,810.21~4,594.56 mg/100 g (dry weight). L-glutamic acid (L-Glu) was the most abundant amino acid, ranging from 1,866.60 mg/100 g for Momotaro to 2,417.45 mg/100 g for Medison. The next most abundant amino acids were L-glutamine (L-Gln) and L-aspartic acid (L-Asp). The three tomato varieties had a good balance of all the essential amino acids except tryptophan. Total essential amino acid content was 274.26~472.71 mg/100 g (dry weight). The following amino acid metabolites were found: L-carnitine (L-Car), hydroxylysine (Hyl), o-phosphoethanolamine (o-Pea), phosphoserine (p-Ser), ${\beta}-alanine$ (${\beta}-Ala$), N-methyl-histidine (Me-His), ethanolamine (EtNH2),and L-citrulline(L-Cit). Large quantities of GABA were found in all three varieties: 666.95-868.48 mg/100g (dry weight). These results support the use of these tomato varieties as nutritious food materials.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1697-1705
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• 2020

Meju, a type of fermented soybean paste, is used as a starter in the preparation of various Korean traditional soybean-based foods. In this study, we performed Illumina-MiSeq paired-end sequencing for microbial communities and mass spectrometry analysis for metabolite profiling to investigate the differences between 11 traditional meju products from different regions across Korea. Even though the bacterial and fungal communities showed remarkable variety, major genera including Bacillus, Enterococcus, Variovorax, Pediococcus, Weissella, and Aspergillus were detected in every sample of meju. The metabolite profile patterns of the 11 samples were clustered into two main groups: group I (M1-5) and group II (M6-11). The metabolite analysis indicated a relatively higher amino acid content in group I, while group II exhibited higher isoflavone, soyasaponin, and lysophospholipid contents. The bioactivity analysis proved that the ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was higher in group II and the FRAP (ferric reducing antioxidant power) activity was higher in group I. The correlation analysis revealed that the ABTS activity was isoflavonoid, lipid, and soyasaponin related, whereas the FRAP activity was amino acid and flavonoid related. These results suggest that the antioxidant activities of meju are critically influenced by the microbiome and metabolite dynamics.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.296-304
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• 2009

The nutritional significance of essential amino acids, as well as non-essential amino acids, is well documented in poultry production with regards to growth performance and protein accretion. However, the function of amino acids in the stress response is still unclear. L-Pipecolic acid, a L-lysine metabolite in the brain, induced a hypnotic and sedative effect acting via the ${\gamma}$- aminobutyric acid receptors. L-Arginine also induced a sedative effect via its metabolism to L-ornithine. In addition, three-carbon nonessential amino acids like L-alanine, L-serine and L-cysteine also induced sedative effects. These facts suggest that the requirement for amino acids in both essential and non-essential types may require reconsideration to add the concept of stress amelioration in the future.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.50-58
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• 2018

Elephant garlic (Allium ampeloprasum var. ampeloprasum), which belongs to the Alliaceae family along with onion and garlic, has a flavor and shape similar to those of normal garlic but is not true garlic. Additionally, its properties are largely unknown, and its processing and product development have not been reported. In this study, we focused on using elephant garlic to produce a new type of vinegar, for which the market is rapidly growing because of its health benefits. First, we evaluated the effects of elephant garlic addition on acetic acid fermentation of rice wine by Acetobacter pasteurianus. In contrast to normal garlic, for which 2% (w/v) addition completely halted fermentation, addition of elephant garlic enabled slow but successful fermentation of ethanol to acetic acid. Metabolite analysis suggested that sulfur-containing volatile compounds were less abundant in elephant garlic than in normal garlic; these volatile compounds may be responsible for inhibiting acetic acid fermentation. After acetic acid fermentation, vinegar with elephant garlic did not have any sulfur-containing volatile compounds, which could positively contribute to the vinegar flavor. Moreover, the amino acid profile of the vinegar suggested that nutritional and sensory properties were more enhanced following addition of elephant garlic. Thus, elephant garlic may have applications in the development of a new vinegar product with improved flavor and quality and potential health benefits.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.239-245
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• 1998

To investigate the formation of bound residue with soil organic materials by oxidative coupling, nitroaromatics and their reduced metabolites, the insecticide parathion and the herbicide asulam were incubated with oxidoreductase, laccase or horseradish peroxidase, in the presence or absence of humic monomers. Most of aminotoluenes and amino-nitrophenols were completely transformed while most of nitrotoluenes and nitrophenols remained unchanged by a lactase or horseradish peroxidase in the presence or absence of humic monomers. Amino-nitrotoluenes were not transformed without humic monomers, but the addition of various humic monomers caused a considerable difference in the transformation of amino-nitrotoluenes by a lactase or horseradish peroxidase. Amino-nitrotoluenes were most transformed in the presence of catechol, syringaldehyde and protocatechuic acid. The insecticide parathion with nitro group and its metabolite were not mostly transformed in the presence or absence of humic monomers. The herbicide asulam with amino group remained unchanged without humic monomers as well, but the stimulating effect on the transformation of asulam was caused by the addition of catechol, syringaldehyde, protocatechuic acid or caffeic acid with a lactase.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.1
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• pp.77-83
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• 1999

Grown in the secondary broth of production media, the strain Streptomyces albulus has increased more the production of its metabolite ${\varepsilon}$-poly-L-lysine, one of poly(amino acid)s used as disinfecting food additives, than the strain in the primary culture of growth nutrients. Having the strain removed, the large concentrate obtained by ultrafiltrating the secondary culture broth. The concentrated production broth exchanged into followed by detecting in UV flowcell at 220nm the peptide bond of the components eluting the adsorbed proteins and polylysine with NaCl salt of gradient concentration, and has separated into five components. Among them the component in the fourth peak fraction has proved to be the pure ${\varepsilon}$-poly-L-lysine after the portion being hydrolyzed the fraction with HCl into amino acid followed by being the composing amino acid analysis.

• Animal Bioscience
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• v.36 no.3
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• pp.506-520
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• 2023

Objective: Japanese Brown (JBR) cattle, especially the Kochi (Tosa) pedigree (JBRT), is a local breed of moderately marbled beef. Despite the increasing demand, the interbreed differences in muscle metabolites from the highly marbled Japanese Black (JBL) beef remain poorly understood. We aimed to determine flavor-related metabolites and postmortem metabolisms characteristic to JBRT beef in comparison with JBL beef. Methods: Lean portions of the longissimus thoracis (loin) muscle from four JBRT cattle were collected at 0, 1, and 14 d postmortem. The muscle metabolomic profiles were analyzed using capillary electrophoresis time-of-flight mass spectrometry. The difference in post-mortem metabolisms and aged muscle metabolites were analyzed by statistical and bioinformatic analyses between JBRT (n = 12) and JBL cattle (n = 6). Results: A total of 240 metabolite annotations were obtained from the detected signals of the JBRT muscle samples. Principal component analysis separated the beef samples into three different aging point groups. According to metabolite set enrichment analysis, post-mortem metabolic changes were associated with the metabolism of pyrimidine, nicotinate and nicotinamide, purine, pyruvate, thiamine, amino sugar, and fatty acid; citric acid cycle; and pentose phosphate pathway as well as various amino acids and mitochondrial fatty acid metabolism. The aged JBRT beef showed higher ultimate pH and lower lactate content than aged JBL beef, suggesting the lower glycolytic activity in postmortem JBRT muscle. JBRT beef was distinguished from JBL beef by significantly different compounds, including choline, amino acids, uridine monophosphate, inosine 5'-monophosphate, fructose 1,6-diphosphate, and betaine, suggesting interbreed differences in the accumulation of nucleotide monophosphate, glutathione metabolism, and phospholipid metabolism. Conclusion: Glycolysis, purine metabolism, fatty acid catabolism, and protein degradation were the most common pathways in beef during postmortem aging. The differentially expressed metabolites and the relevant metabolisms in JBRT beef may contribute to the development of a characteristic flavor.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.451-461
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• 2020

This study was carried out to investigate the value of yellow cherry tomato as a food material. Contents of nutritional and bioactive compound were determined from yellow cherry tomato. 17 of amino acids occurred. L-Glutamic acid (45.15%), L-glutamine (22%) and L-aspartic acid (11%) were the main amino acids. 8 of essential amino acids were found except tryptophan. γ-aminobutyric acid (GABA) was found in high contentration (258.58 mg/100g). Contents of Lycopene and β-carotene were 2.18 mg/100 g and 9.90 mg/100 g, respectively. Yellow cherry tomato contained naringenin chalcone, quercetin-3-rutinoside(rutin), 5-caffeoylquinic acid, 3-caffeoylquinic acid, and quercetin-3-apiosylrutinoside that have various bioactivities. These results revealed that yellow cherry tomato would be very useful and valuable food material.

• Biomolecules & Therapeutics
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• v.26 no.2
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• pp.167-174
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• 2018

Alterations in sulfur amino acid metabolism are associated with an increased risk of a number of common late-life diseases, which raises the possibility that metabolism of sulfur amino acids may change with age. The present study was conducted to understand the age-related changes in hepatic metabolism of sulfur amino acids in 2-, 6-, 18- and 30-month-old male C57BL/6 mice. For this purpose, metabolite profiling of sulfur amino acids from methionine to taurine or glutathione (GSH) was performed. The levels of sulfur amino acids and their metabolites were not significantly different among 2-, 6- and 18-month-old mice, except for plasma GSH and hepatic homocysteine. Plasma total GSH and hepatic total homocysteine levels were significantly higher in 2-month-old mice than those in the other age groups. In contrast, 30-month-old mice exhibited increased hepatic methionine and cysteine, compared with all other groups, but decreased hepatic S-adenosylmethionine (SAM), S-adenosylhomocysteine and homocysteine, relative to 2-month-old mice. No differences in hepatic reduced GSH, GSH disulfide, or taurine were observed. The hepatic changes in homocysteine and cysteine may be attributed to upregulation of cystathionine ${\beta}-synthase$ and down-regulation of ${\gamma}-glutamylcysteine$ ligase in the aged mice. The elevation of hepatic cysteine levels may be involved in the maintenance of hepatic GSH levels. The opposite changes of methionine and SAM suggest that the regulatory role of SAM in hepatic sulfur amino acid metabolism may be impaired in 30-month-old mice.