• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1416-1426
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• 2022

The need to discover new types of antimicrobial agents has grown since the emergence of antibiotic-resistant pathogens that threaten human health. The world's oceans, comprising complex niches of biodiversity, are a promising environment from which to extract new antibiotics-like compounds. In this study, we newly isolated Pseudomonas sp. NIBR-H-19 from the gut of the sea roach Ligia exotica and present both phenotypes and genomic information consisting of 6,184,379 bp in a single chromosome possessing a total of 5,644 protein-coding genes. Genomic analysis of the isolated species revealed that numerous genes involved in antimicrobial secondary metabolites are predicted throughout the whole genome. Moreover, our analysis showed that among twenty-five pathogenic bacteria, the growth of three pathogens, including Staphylococcus aureus, Streptococcus hominis and Rhodococcus equi, was significantly inhibited by the culture of Pseudomonas sp. NIBR-H-19. The characterization of marine microorganisms with biochemical assays and genomics tools will help uncover the biosynthesis and action mechanism of antimicrobial metabolites for development as antagonistic probiotics against fish pathogens in an aquatic culture system.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.16-16
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• 2023

Metabolomics is the study of global metabolite profiles in a system (cell, tissue, or organism) under a given set of conditions. Metabolomics has its roots in early metabolite profiling studies but is now a rapidly expanding area of scientific research in its own right. In this study, the applications of metabolomics in natural product studies are explored. Ginseng is a well-known herbal medicine and has various pharmacological effects, which include antiaging, anticancer, antifatigue, memory enhancing, immunomodulatory, and stress reducing effects. Metabolomic analysis of organic acids has not been performed for evaluation whether ginseng has been cultivated using conventional or environmental-friendly farming methods. In this study, profiling analysis was conducted for organic acids (OAs) in ginseng roots produced using conventional or environmentfriendly farming methods at five locations in each of five regions. In OA profiles, lactic acid was the most abundant OA in all regions, with the exception for environmentally friendly farmed ginseng in two of the five regions, in which glycolic acid was most abundant OA. OA profiles in all regions showed isocitric acid levels were increased by environment-friendly cultivation, which suggests metabolic differences associated from farming method, and that isocitric acid might be a useful discriminatory biomarker of environmental-friendly and conventional cultivation. The results of the present study suggest metabolomic studies of OAs in ginseng roots might be useful for monitoring whether ginseng has been cultivated using conventional or environmentally friendly farming methods.

• Natural Product Sciences
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• v.21 no.4
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• pp.273-277
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• 2015

Comprehensive chemical analysis of extracts and fractions of marine actinomycete strains led to the discovery of a new minor secondary metabolite, salternamide E (1), from a saltern-derived halophilic Streptomyces strain. The planar structure of salternamide E (1) was elucidated by a combinational analysis of spectroscopic data including NMR, MS, UV, and IR. The absolute configuration of salternamide E (1) was determined by circular dichroism spectroscopic analysis. Salternamide E displayed weak cytotoxicity against various human carcinoma cell lines.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.4
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• pp.132-138
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• 2018

The plucking season of green tea leaves is one of the important parameters that decide their metabolic quality. Here, we performed the identification and quantity analysis of the metabolites of the green tea using NMR spectroscopy. We assigned the $^1H$ resonances for sixteen metabolites. This analysis found that four metabolites, gallic acid, quinic acid, theobromine and ECG, exhibited clear discrimination of green teas by the three different grades, Ujeon, Sejak and Jungjak. Our results suggest that these four metabolites could be used for diagnostics for quality control of green tea.

• Journal of Microbiology
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• v.40 no.4
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• pp.289-294
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• 2002

The fungal strain SW-3 having antimicrobial activity was isolated from soil of crucified plants in Pocheon, Kyungki-Do, Korea. Strain SW-3 was identified as Alternaria brassicicola by its morphological characteristics, and confirmed by the analysis of the 18S gene and ITS regions of rDNA. The fungus showed a similarity of 99% with Alternaria brassicicola in the 18S rDNA sequence analysis. A. brassicicola has been reported to produce an antitumor compound, called depudecin. We found that strain SW-3 produced antimicrobial metabolites, in addition to depudecin, during sporulation under different growth conditions. The metabolite of the isolated fungus was found to have strong antifungal activity against Microsporium canis and Trichophyton rubrum, and antibacterial activity against Staphylococcus aureus and Pseudomonas aerogenes. The amount and kind of metabolites produced by the isolate were affected by growth conditions such as nutrients and growth periods.

• Journal of the Korean Chemical Society
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• v.63 no.2
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• pp.78-84
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• 2019

High-resolution $^1H$ NMR spectroscopic technique has been widely used as one of the most powerful analytical tools in food chemistry as well as to define molecular structure. The $^1H$ NMR spectra-based metabolomics has focused on classification and chemometric analysis of complex mixtures. The principal component analysis (PCA), an unsupervised clustering method and used to reduce the dimensionality of multivariate data, facilitates direct peak quantitation and pattern recognition. Using a combination of these techniques, the various green teas and black teas brewed were investigated via metabolite profiling. These teas were characterized based on the leaf size and country of cultivation, respectively.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.264-268
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• 2021

Tuberculosis (TB) is a major infectious disease that threatens the life and health of people globally. Here, we performed a metabolomic analysis of serum samples from patients with intractable TB to identify biomarkers that might shorten the TB treatment period. Serum samples collected at the commencement of patients' treatment and healthy controls were analyzed using the capillary electrophoresis and time-of-flight mass spectrometry metabolome analysis method. The analysis identified the metabolites cystine, kynurenine, glyceric acid, and cystathionine, which might be useful markers for monitoring the TB treatment course. Furthermore, our research may provide experimental data to develop potential biomarkers in the TB treatment course.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.193-199
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• 2019

Perilla seed oil is considered to be a rich source of omega-3 fatty acids and phenolic compounds, which have various health benefits. To improve its oil content and nutritional quality, 29 varieties of perilla have been bred, but their nutritional qualities, including the fatty acid and phenolic compound contents, have not been investigated. Therefore, in this study, the seed metabolite profiles, including the fatty acids, of these 29 perilla varieties were analyzed. Palmitic acid, stearic acid, linoleic acid, linolenic acid, rosmarinyl glucoside, and rosmarinic acid were identified as the major metabolites of perilla. The fatty acid contents were higher in the Okdong, Deulsaem, Daesil, Joim, Yeupsil, Danjo, and Joongmo5103 varieties (in order). However, the total phenolic compounds and antioxidative activities of Okdong and Deulsaem were relatively low, whereas the fatty acid and total phenol contents of Joim, Yeupsil, and Danjo were relatively high. These results may be useful for comparing the nutritional quality of the 29 perilla varieties.

• YAKHAK HOEJI
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• v.51 no.3
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• pp.206-213
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• 2007

Recently estimating the uncertainty of an analytical result has become an essential part of quantitative analysis. This study describes the uncertainty of the measurement for the determination of methamphetamine and its major metabolite amphetamine in human hair, The method consists of washing, drying, weighing, incubation and extraction with methanolic HCI solution, clean-up, trifluoroacetyl derivatization, and qualification/quantification of residues by gas chromatography/mass spectrometry (GC/MS). Traceability of measurement was established through traceable standards and calibrated volumetric equipment and measuring instruments. Measurement uncertainty associated with each analyte in real samples was estimated using quality control (QC) data. The main source of combined standard uncertainty comprised two components, which are uncertainties associated with calibration linearity and variations in QC, while those associated with preparation of analytical standards and sample weighing were not so important considering the degree of contribution. Relative combined standard uncertainties associated with the described method ranged for individual analytes from 4.99 to5.03%.