• 한국미생물·생명공학회지
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• 제38권4호
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• pp.475-480
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• 2010

Actinomycetes are Gram-positive soil bacteria and one of the most important industrial microorganisms due to superior biosynthetic capabilities of many valuable secondary metabolites as well as production of various valuable bioconversion enzymes. Among them are cytochrome P450 hydroxylase (CYP), which are hemoproteins encoded by a super family of genes, are universally distributed in most of the organisms from all biological kingdoms. Actinomycetes are a rich source of soluble CYP enzymes, which play critical roles in the bioactivation and detoxification of a wide variety of metabolite biosynthesis and xenobiotic transformation. Cyclosporin A (CyA), one of the most commonly-prescribed immunosuppressive drugs, was previously reported to be hydroxylated at the position of 4th N-methyl leucine by a rare actinomycetes called Sebekia benihana, leading to display different biological activity spectrum such as loss of immunosuppressive activities yet retaining hair growth-stimulating side effect. In order to improve this regio-selective CyA hydroxylation in S. benihana, previously-identified several secondary metabolite up-regulatory genes from Streptomyces coelicolor and S. avermitilis were heterologously overexpressed in S. benihana using an $ermE^*$ promoter-containing Streptomyces integrative expression vector. Among tested, SCO4967 encoding a conserved hypothetical protein significantly stimulated region-specific CyA hydroxylation in S. benihana, implying that some common regulatory systems functioning in both biosynthesis and bioconversion of secondary metabolite might be present in different actinomycetes species.

• 분석과학
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• 제24권2호
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• pp.142-149
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• 2011

Resveratrol을 GC/TOF-MS를 이용하여 대사체를 확인한 결과, 두 개의 phenyl기를 연결하는 이중결합이 단일결합으로 환원된 구조로 추정되었다. 또한, GC/MSD를 이용하여 resveratrol 및 내인성스테로이드의 분석법에 대한 유효성을 점검한 결과, 회수율은 96.47 - 114.74%의 범위로 나타났으며, intra-day와 inter-day의 정밀도는 1.40 - 10.87%과 1.10 - 10.93% 그리고 정확도는 80.03 - 119.92%과 80.02 - 119.56%로 조사되었고, 모두 0.996이상의 직선성을 나타내어 유효한 분석 방법으로 검증되었다. 한편, 지원자들에게 resveratrol을 경구투여 한 요시료로부터 resveratrol과 그 대사체에 대한 상관성을 조사해본 결과, 요중 최대농도 도달시간이 일반적인 약물(1 - 2시간) 보다 긴 10 - 15시간에 나타났으며, 대사체로의 전환율은 남성보다 여성이 높게 나타났다. 한편, 내인성 스테로이드는 약물 복용 후 20시간 까지는 resveratrol 및 그 대사체와 다소 유사한 분비형태를 나타내었으며, estrone과 estradiol의 경우 여성이 남성에 비해 이 약물에 대한 민감성이 높게 나타났다. 그 외의 내인성 스테로이드는 유의할만한 차별된 분비형태의 변화가 나타나지 않았다. 따라서 resveratrol의 경우 약물의 활성이 남성보다는 여성에게 유의한 영향을 미치는 것으로 추측되었다.

• Toxicological Research
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• 제27권4호
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• pp.191-203
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• 2011

There has been growing concern about the toxicity of phthalate esters. Phthalate esters are being used widely for the production of perfume, nail varnish, hairsprays and other personal/cosmetic uses. Recently, exposure to phthalates has been assessed by analyzing urine for their metabolites. The parent phthalate is rapidly metabolized to its monoester (the active metabolite) and also glucuronidated, then excreted. The objective of this study is to evaluate the toxicity of phthalic acid (PA), which is the final common metabolic form of phthalic acid esters (PAEs). The individual PA isomers are extensively employed in the synthesis of synthetic agents, for example isophthalic acid (IPA), and terephthalic acid (TPA), which have very broad applications in the preparation of phthalate ester plasticizers and components of polyester fiber, film and fabricated items. There is a broad potential for exposure by industrial workers during the manufacturing process and by the general public (via vehicle exhausts, consumer products, etc). This review suggests that PA shows in vitro and in vivo toxicity (mutagenicity, developmental toxicity, reproductive toxicity, etc.). In addition, PA seems to be a useful biomarker for multiple exposure to PAEs in humans.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.96-104
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• 2019

Beauveria bassiana, one of the most common entomopathogenic fungi, has been isolated, pre defined and characterized in-house from soil of tea cultivation area. Experiments have been performed to verify the presence of chitinase as intracellular metabolite and its release as extracellular product rendering the spores with biopesticide activity. Although there are many responsible enzymes for the pest killer action of B. bassiana, binding property of chitinase depending on presence as well as absence of serine supplemented in the media has been studied with respect to the production and kinetics. A programmed investigation conclusively indicates that the isolated spore (hyphae) of B. bassiana has been metabolically enriched with the enzyme chitinase in presence of an externally added amino acid serine with its inhibitory kinetics.

• 대한한의학방제학회지
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• 제11권2호
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• pp.185-196
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• 2003

Depression is very common mental disorder, so many people suffer from it, which makes the treatment of depression important. Many drugs to treat depression were developed and being prescripted. But they have a lot of side effects, so it needs to develop drugs without side effects or with less side effects. Herbal medicines have been used to treat not only physical disorder but also mental disorder and it has been reported that they have less side effects. Therefore, there is the need to discover and use herbal medicine with antidepressant effect. The purpose of this study was to reseach Antidepressant effect of Licium chinense Mill. and its influence on serotonin and its metabolite of depression model rats. We used 'forced swimming test(FST)' to know antidepressant effect of Licium chinense Mill. and HPLC to check the influence on serotonin and its metabolite(5-HIAA) of Licium chinense Mill. after rats' brains were divided into cerebral cortex, striatum, hypothalamus and hippocampus. The results were obtained as follows : In the study of antidepressant effect by 'forced swimming test(FST)' method, Licium chinense Mill. had a significant antidepressant effect. In the study of influence on serotonin and 5-HIAA by HPLC, Licium chinense Mill. mainly increased serotonin and 5-HlAA of cerebral cortex and striatum signigficantly among 4 parts of rat's brain above-mentioned. These results suggest that Licium chinense Mill. has antidepressant effect that may be related with the increase of serotonin and its metabolite as its mechanism, but more precise experiments will be need to prove their relation.

• 약학회지
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• 제45권4호
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• pp.378-386
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• 2001

A purified histone Hl protein, p961, which plays a role in mediating the condensation of DNA into chromatin, was recently proved as an arthritis-suppressing agent in the mouse CIA model. The pharmacokinetics of p961 was carried out in rats and rabbits. The rat's blood, bile and urine samples were serially collected from the femoral vein, common bile duct, and bladder respectively, after bolus i.v. injection at low (10 mg/kg) and high (30 mg/mg) doses. The rabbit's blood samples were also collected from the marginal ear vein after bolus i.v. injection at a dose 10 mg/kg. p961 and its major metabolite in the physiological samples were analyzed by reverse-phase HPLC using a Yydac C4 protein column and a multistep water-acetonitrile gradient containing 0.24% trifluoroacetic acid. The major pharmacokinetic parameters (AUC, $C_{max}$, MRT, $t_{1}$2/, $V_{ss}$ and Cl) were estimated from the time course of plasma p961 and metabolite concentrations using WinNonlin. A two-compartment model was chosen for p961 as the most appropriate pharmacokinetic model. After i.v. injection of p961 at doses of 10 mg/kg and 30 mg/kg, more than 80% of p961 was removed rapidly from the plasma within 15 min. The plasma half-life of p961 in rats and rabbits was found not to exceed 12 min. p961 (22448.9 mol wt) was rapidly cleaved to 21612 mot wt fragment and the breakdown product appeared rapidly in the circulation with no lag phase. p961 and metabolite were not detected in rat urine and bile....

• The Plant Pathology Journal
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• 제39권4호
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• pp.397-408
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• 2023

Fire blight disease, caused by Erwinia amylovora, is a devastating affliction in apple cultivation worldwide. Chemical pesticides have exhibited limited effectiveness in controlling the disease, and biological control options for treating fruit trees are limited. Therefore, a relatively large-scale survey is necessary to develop microbial agents for apple trees. Here we collected healthy apple trees from across the country to identify common and core bacterial taxa. We analyzed the endophytic bacterial communities in leaves and twigs and discovered that the twig bacterial communities were more conserved than those in the leaves, regardless of the origin of the sample. This finding indicates that specific endophytic taxa are consistently present in healthy apple trees and may be involved in vital functions such as disease prevention and growth. Furthermore, we compared the community metabolite pathway expression rates of these endophyte communities with those of E. amylovora infected apple trees and discovered that the endophyte communities in healthy apple trees not only had similar community structures but also similar metabolite pathway expression rates. Additionally, Pseudomonas and Methylobacterium-Methylorobrum were the dominant taxa in all healthy apple trees. Our findings provide valuable insights into the potential roles of endophytes in healthy apple trees and inform the development of strategies for enhancing apple growth and resilience. Moreover, the similarity in cluster structure and pathway analysis between healthy orchards was mutually reinforcing, demonstrating the power of microbiome analysis as a tool for identifying factors that contribute to plant health.

• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.45-50
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• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• Mass Spectrometry Letters
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• 제8권4호
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• pp.90-97
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• 2017

Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3602-3608
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• 2013

Saccharomyces cerevisiae, which is a common species of yeast, is by far the most extensively studied model of a eukaryote because although it is one of the simplest eukaryotes, its basic cellular processes resemble those of higher organisms. In addition, yeast is a commercially valuable organism for ethanol production. Since the yeast data can be extrapolated to the important aspects of higher organisms, many researchers have studied yeast metabolism under various conditions. In this report, we analyzed and compared metabolites of Saccharomyces cerevisiae under salt and pH stresses of various strengths by using two-dimensional NMR spectroscopy. A total of 31 metabolites were identified for most of the samples. The levels of many identified metabolites showed gradual or drastic increases or decreases depending on the severity of the stresses involved. The statistical analysis produced a holistic outline: pH stresses were clustered together, but salt stresses were spread out depending on the severity. This work could provide a link between the metabolite profiles and mRNA or protein profiles under representative and well studied stress conditions.