• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.875-880
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• 2010

Bacterial enoyl-ACP reductase (FabI) has been demonstrated to be a novel antibacterial target. In the course of our screening for FabI inhibitors, we isolated two methyl-branched fatty acids from Streptomyces sp. A251. They were identified as 14-methyl-9(Z)-pentadecenoic acid and 15-methyl-9(Z)-hexadecenoic acid by MS and NMR spectral data. These compounds inhibited Staphylococcus aureus FabI with $IC_{50}$ values of 16.0 and $16.3\;{\mu}M$, respectively, but did not affect FabK, an enoyl-ACP reductase of Streptococcus pneumonia, at $100\;{\mu}M$. Consistent with their selective inhibition for FabI, they blocked intracellular fatty acid synthesis as well as the growth of S. aureus, but did not inhibit the growth of S. pneumonia. Additionally, these compounds showed reduced antibacterial activity against fabI-overexpressing S. aureus, compared with the wild-type strain. These results demonstrate that the methylbranched fatty acids show antibacterial activity by inhibiting FabI in vivo.

• 약학회지
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• 제26권1호
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• pp.1-8
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• 1982

Derivation of triterpenoids and then the screening for corticomimetics among them is our primary interest. $C_{11}$-oxo-triterprenoids except glycyrrhetinic acid are rarely found in the plant kingdom. Based on the facts that $C_{3}$ and $C_{11}$-Oxo-group are essential for the corticoid-like-activity through its competitive inhibition on the corticoid-5.betha.-reductase, it was attempted to produce artificial inhibitor on the enzyme by introducing $C_{11}$-oxo group to the triterpenoids of oleanene series such as oleanolic acid and hederagenin. We could obtain the $C_{11}$-oxo-oleanolic acid m.p. $264-6^{\circ}$, uv ${\lambda}max$ 249 and $C_{11}$-oxo-hederagenin amorp. uv ${\lambda}max$ 251 by acetylation, $CrO_{3}$-oxid., and deacetylation. Glycyrrhetinic acid, a natural 11-oxo-compound and the other 11-oxo-derivatives of oleanolic acid and hederagenin were compared in their inhibitory activity on the corticoid-5.betha.-reductase. The inhibitory activity of those compound were decreased in the order of $C_{11}$-oxo-oleanolic acid, $C_{11}$-oxo- hederagenin, glycyrrhetinic acid. This suggests more strong corticomimetic activity of those artificially derived $C_{11}$-oxo-oleanolic acid and $C_{11}$-oxa-hederagenin. Their Ki value were $4.6{\times}10^{-4}M$ and $5.8{\times}10^{-4}M$ respectively.

• 한국토양비료학회지
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• 제46권1호
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• pp.32-39
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• 2013

The relationship between relative water contents of lettuce leaves and biochemical activities in lettuce was examined in this study to explore an adaptation response of lettuce to water stress from soils. Soil water contents and relative water contents of leaves were positively related to show $R^2$=0.8728. Hydrogen peroxide contents of leaves rapidly increased with reduction of soil water content, whereas soluble protein contents and dry matters rapidly decreased. And chlorophyll a and b contents of leaves decreased with increase in carotenoid content. Furthermore, the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) increased dramatically, and mRNA transcript levels of APX, MDHAR and DHAR also increased. Relationship of relative water content of lettuce leaves to hydrogen peroxide, to ascorbate peroxidase activity, to dehydroascorbate reductase activity, and to monodehydroascorbate reductase activity was shown to be positively correlated. It is highly plausible from this study that these enzyme activities could be developed as an indicator of water states in soils.

• 약학회지
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• 제48권5호
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• pp.291-296
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• 2004

Sparganium stoloniferum Buch.-Ham. (Sparganiaceae) is a perennial herb which has been used as treatments for menstrual disorder, galactagogue and endometriosis in folk remedies. The Sparganii Rhizoma processed, heated with vinegar, used to different purpose compared with origin in medicine. In order to estimate the different effects between processed (PSR) and unprocessed (USR) Sparganii Rhizoma, extraction and systemic fractionation of the rhizomes were archived. Inhibitory effects of the extracts as well as the fractions of PSR and USR on rat lens aldose reductase and on rat platelet aggregation were investigated for the prevention or the treatment of chronic diabetic complications. Their antioxidant effects, measured using lipid peroxidation of liver tissue and radical scavenging activities on 1,1-diphenyl-picrylhydrazyl in vitro, were evaluated. The most of biological activities tested except rat platelet aggregation, fractions from PSR were shown to exhibit stronger activities than those from USR. It seems that caused by changing of the chemical components by heating process in conditioned with acetic acid. Compounds isolated were shown to significant inhibitory activity on rat lens aldose reductase. Inhibitory activity of compounds isolated on rat lens aldose reductase have been tested in vitro. $IC_{50}$/ (6.31 $\mu$M) of cerebroside I (V) was nearly equal to that (6.32 $\mu$M) of a reference compound, tetrametbylene glutaric acid (TMG).

• Journal of Applied Biological Chemistry
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• 제52권4호
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• pp.216-220
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• 2009

Aldo-keto reductase family 1 B10 (AKR1B10) has been considered as a potential cancer therapeutic target. Ethanol extracts prepared from 82 Korean local plants were examined for their antioxidant activity and inhibitory effects on recombinant human AKR1B10 (rhAKR1B10) in vitro. 21 extracts showed more than 80% of ABTS radical scavenging activity at $100\;{\mu}g/mL$ and 11 extracts inhibited more than 50% of rhAKR1B10 activity at $10\;{\mu}g/mL$. Especially, 9 extracts showed potent inhibition on rhAKR1B10 activity compared with positive control tetramethylene glutaric acid.

• Horticulture, Environment, and Biotechnology : HEB
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• 제59권6호
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• pp.899-907
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• 2018

The methanol extracts of flowers obtained from 67 plant species were screened for their inhibitory activity on aldose reductase (AR). Alnus japonica, Aster spathulifolius, Chionanthus retusus, Morus bombycis, Crysanthemum boreale, Persicaria tinctoria, Platycarya strobilacea, and Serratula coronata var. insularis exhibited potent aldose reductase inhibitory (ARI) activity. HPLC-UV analysis of quercetin, an AR inhibitory flavonoid, was performed on extracts showing strong ARI activity. Quercetin was detected in C. retusus, C. boreale, P. tinctoria, and S. coronata var. insularis at concentrations of 1.33, 1.56, 0.82, and $3.37mg\;g^{-1}$ extract, respectively, indicating that quercetin contributed to the ARI activity of these extracts. In the samples in which quercetin was absent, other compounds may be responsible for their potent ARI activity. These results serve as a basis for further studies regarding the bioactive components responsible for the inhibitory effects of various flower extracts on AR activity.

• 한국식품영양학회지
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• 제15권4호
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• pp.307-313
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• 2002

체내 cholesterol 수치를 낮추기 위하여 HMG-CoA reductase 활성을 저해하는 물질들을 닭에게 급여하여 in vitro상에서 검토한 결과, HMG-CoA reductase 활성에 대한 마늘, lovastatin과 copper의 순으로 저해능은 51.3%, 87.5%, 82.0%이었다. 또한 혈장, 가슴조직, 간장의 cholesterol 함량에 대한 마늘(3% in diet), lovastatin(300mg/Kg of diet), copper(200mg/Kg of diet)의 효과를 검토하였다. 혈장 중의 cholesterol 함량과 HDL, LDL cholesterol 함량은 3% 마늘의 투여로 감소되어졌으나 copper의 투여는 오히려 증가하였고, lovastatin 투여에 의한 차이는 나타나지 않았다. 그리고 간장과 가슴조직의 cholesterol과 triglyceride는 사료에 cholestrol의 수치를 저하시키는 물질을 첨가하였으나 별다른 차이가 없었다.

• 한국동물학회지
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• 제38권4호
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• pp.565-569
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• 1995

분열형 호모인 Schizosaccbarornyces pombe에서 RecA 유사 단백질은 hydroxyurea (HU)나 methotrexate (MTX)와 같은 nucleotide pool 형성에 관여하는 효소의 저해제에 의해 유도발현된다. 본 연구에서는 대장균의 RecA 단백질과 S. pombe의 ribonucleotide reductase가 구조적으로 유사한지를 RecA 항체를 이용한 면역침전법과 [5-$^3$H]CDP를 기질로하는 thin layerchromatography방법을 통하여 알아보고자 하였다. S. pombe의 rinonucleotide reductase활성은 100mM HU에 의해 대조군에 비해 26.3% 저해되었으며, RecA 항체를 이용한 면역침전에 의해서도 43.3% 저해되었다. 이와 같은 결과는 S. pombe의 rinonucleotide reductase가 대장균의 RecA 단백질과 구조적으로 유사함을 시사하는 것이다.

• Journal of Microbiology and Biotechnology
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• 제21권5호
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• pp.464-469
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• 2011

The arsH gene is one of the arsenic resistance system in bacteria and eukaryotes. The ArsH protein was annotated as a NADPH-dependent flavin mononucleotide (FMN) reductase with unknown biological function. Here we report for the first time that the ArsH protein showed high ferric reductase activity. Glu104 was an essential residue for maintaining the stability of the FMN cofactor. The ArsH protein may perform an important role for cytosolic ferric iron assimilation in vivo.

• 약학회지
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• 제46권1호
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• pp.24-29
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• 2002

Enoyl-Acyl Carrier Protein Reductase (Fabl) of bacteria is hem as an important target for new antibacterial drugs and plays a determinant role in completing cycles of elongation in type-H fatty acid synthase system. In this study, a fabI gene from Staphylococcus aureus 6538p cloned in pET-l4b vector and FabI protein was over-produced in Escherichaia coli BL2l (DE3). $NH_2$-terminal His-tagged FabI protein was purified by nickel-nitrilotriacetic acid (Ni-NTA) metalaffinity chromatography Purified 6xHis-tagged FabI showed a catalytic activity on tram - 2 - octenoyl - N -acethlcysteamine by utilizing NADPH as a cofactor. For the discovery of new FabI inhibitors from chemical libraries, a target-oriented screening system using a 96-well plate was developed. About 10,000 chemical libraries from Korea Chemical Bank wore tested in this screening system, and 26 chemicals (0.25%) among them showed an inhibitory activity against FabI enzyme. This result showed that a new screening system can be used for the discovery of new FabI inhibitors.