• Natural Product Sciences
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• 제8권3호
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• pp.108-110
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• 2002

A new ardimerin (1) was isolated from the herb of Ardisia japonica. Its structure was determined by the elucidation of spectroscopic data and a chemical transformation. Compound (1) showed potent radical scavenging effect on DPPH radical $(IC_{50},\;0.32\;{\m}M)$.

• The Plant Pathology Journal
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• 제27권3호
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• pp.242-248
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• 2011

Several soil bacteria were found to degrade N-Acylhomoserine lactones (NAHLs), thereby interfering with the bacterial quorum sensing system. In this research, fifteen strains of NAHL degrading rhizobacteria were isolated from potato rhizosphere. Based on phenotypic characteristics and 16S rDNA sequence analyses, the strains were identified as members of genera Bacillus, Streptomyces, Arthrobacter, Pseudomonas and Mesorhizobium. All tested isolates were capable to degrade both synthetic and natural NAHL produced by Pectobacterium carotovorum subsp. carotovorum (Pcc) strain EMPCC. In quorum quenching experiments selected isolates, especially Mesorhizobium sp., were markedly reduced the pathogenicity of Pcc strain EMPCC in potato tubers and totally suppressed tissue maceration on potato tubers. These led to consider the latter as a useful biocontrol agent against Pectobacterium spp.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.188-190
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• 1998

Penicillide, having a 5H, 7H-dibenzo［b,g］［1,5］ dioxocin-5-one skeleton, was isolated from the culture broth of Penicillium sp. F60760 as a nonpeptide inhibitor of calpain, a calcium-activated papain-like protease. The $IC_50$ value for the effect of penicillide against m-calpaln was $7.1{\mu}M$. However, penicillide did not inhibit papain at a concentration of $200{\mu}M$. These results suggest that penicillide is a new class of nonpeptide calpain inhibitor having an eight membered lactone ring.

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.787-791
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• 2009

In the course of screening for substances that inhibit etoposide (10 ${\mu}g$/ml)-induced apoptosis in human leukemia U937 cells, fungal strain F000120, which exhibits potent inhibitory activity, was selected. The active compound was purified from an ethyl acetate extract of the microorganism by Sep-pak $C_{18}$ column chromatography and HPLC, and was identified as heptelidic acid (koningic acid) by spectroscopic methods. This compound inhibited caspase-3 induction in U937 cells with an $IC_{50}$ value of 40 ${\mu}M$ after 8 h of etoposide treatment. Fluorescent dye staining with acridine orange and ethidium bromide showed that heptelidic acid inhibited apoptosis. Furthermore, it was found that DNA fragmentation and caspase-3 activation, the biological hallmarks of apoptosis, were inhibited by the compound in a dose-dependent manner, suggesting that heptelidic acid inhibits etoposide-induced apoptosis via downregulation of caspases.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.477-481
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• 2003

The community escape response of Rhodobacter sphaeroides is exerted through the action of CerR and CerI, which code for a LuxR-type regulatory protein and acylhomoserine lactone synthase, respectively. Deletion of chromosomal DNA including cerR and cerI (mutant RI) or insertional interruption of cert (mutant AP3) resulted in two-fold increase in the cellular poly-${\beta}$-hydroxybutyrate (PHB) content In comparison with the wild-type under aerobic growth conditions. The PHB synthase (PhbC) activities of the cer mutants were doubled, and the enzyme expression was regulated at the level of phbC transcription. Thus, CerR, possibly in response to autoinducer (AI), appears to modulate the PHB content of aerobically grown cells by downregulating phbC transcription.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.220-223
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• 2000

Sophorolipid, a glycolipid type biosurfactant produced from Candida Bombicola, inhibited the growth of bacteria and fungi. Between two types of sophorolipid, acid and lactone form, the latter had more strong antimicrobial activity. Culturing parameters including oil substrate, initial glucose concentration, aeration, culture mode, affected the ratio of two forms. The fatty acid moety varied depending on the oil having different fatty acid chains. Minimum inhibitory concentration of lactonic sophorolipid toward Propionibacterium acne was below 0.5ppm. This result indicated the potentials of sophorolipid as antimicrobial agent in various area including cosmetics.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1171-1178
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• 2006

This study examined the effects of flavors, which are usually added to improve the appeal of pharmaceutical agents, on the viscosity and gelling point of 18% (w/w) aqueous poloxamer 407 solutions. Monoterpenes, esters, alcohols, aldehyde ketones and lactone type flavors were examined. The concentrations of flavor ranged from 0.1 to 1.0%(w/w). After adding a flavor to the aqueous poloxamer 407 solution, the viscosity of the solution was measured using a Brookfield viscometer, and the gelling point was determined from the viscosity vs. temperature plot. The gelling point of the aqueous poloxamer 407 solution decreased with increasing concentration of flavors except for coumarin, vanillin and ethylvanillin. Thermal analysis with DSC showed an interaction between the flavors and poloxamer 407. These results suggest that the flavors bind to the hydrophilic end chains of poloxamer 407, which increases the viscosity, causing gelation at lower temperatures.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.240-249
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• 2002

Dibenzyl-g-butyrolactone and 1,2,3,4-tetrahydro-2-naphthoic acid $\gamma$-lactone (TNL) derivatives were synthesized and evaluated for cytotoxic activity against some cancer cell lines. It was found that TNL derivatives with a shorter distance between C-4 in ring A and C'-2 in ring C were more cytotoxic, while dibenzyl-${\gamma}$-butyrolactones with a longer one were nearly inactive. In TNL series, presence of 3,4-dioxy group in ring A and 2-methoxy group in ring C was essential for the enhancement of the activity.

• 생약학회지
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• 제22권2호
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• pp.91-94
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• 1991

Callus was derived from the seedlings of Agastache rugosa(Labiatae). The growth rate of callus and the production of essential oil were studied with the variation of culturing conditions. 2, 4-D 2ppm in the medium was more effective for the production of essential oil than NAA 2ppm. The growth rate of callus and the production of essential oil were inhibited by the illumination of the light. The essential oils from Agastache rugosa and the callus cultivated on the medium containing 2, 4-D 2 ppm and kinetin 0.2 ppm were analysed by TLC, gas chromatography and mass spectrometry. These two oils showed different compositions. The main component of the plant oil, methyl chavicol was not contained in the callus oil.

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.98-107
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• 1995

천연물 중 casbene-type diterpenoid의 하나인 crotonitenone의 합성이 시도되었다. 합성 방법으로는 crotonitenone의 각 부분을 먼저 합성하여 이들을 합하는 방법(convergent method)을 적용하였으며, 각 부분이 최종물질에 적합한 sterochemistry를 갖게 하기 위하여 시작물질로는 chiron으로 S-(-)-citronellol과 IS-chrysanthemic acid를 사용하였다. 환구조를 형성하는데 중요한 역할을 할 TBDMS protecting group이 붙은 phosphonium salt(synthon A) 가 고압반응으로부터 고수율 (70%)로 생성되었다. 또한, 중요한 반응으로서 synthon A와 hydroxy lactone(synthon B)과의 Witting reaction이 성공적으로 이루어졌다. 그러나, TBDMS protecting group의 존재하에 이중 치환된 이중결합(disubstituted double bond)과 삼중치환된 것과의 선택적인 환원의 어려움으로 인하여 최종 물질의 합성방법이 재고되었으며 이에 대해 간단히 논하였다.