• 한국동물위생학회지
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• 제32권3호
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• pp.281-286
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• 2009

Fluoroquinolones in muscle and egg were separated by liquid extraction and determined. The analysis was carried out using following conditions; C18 column ($150{\times}4.6mm$, $5{\mu}m$), mobile phase composed of D.W. (containing 0.4% triethylamine and phosphoric acid) : methanol : acetonitrile (780:100:120, v/v/v), quarternary pump at a flow rate of 0.9ml/min and $20{\mu}l$ of injection volume, fluorescence detector with EX 278nm/Em 456nm. The calibration range of seven fluoroquinolones showed linearity ($r^2{\geq}0.999$) at concentration range of $0.025{\sim}0.8{\mu}g/ml$. The recoveries in fortified muscle and egg represented more than 81.3%. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, saraloxacin and orbifloxacin were 3.1, 2.5, 3.6, 1.7, 0.9, 2.5 and $2.1{\mu}g/kg$, respectively. We also monitored fluoroquinolones residue in the sample (chicken muscle 182, cattle muscle 140, pig muscle 139, egg 212) using EEC-plate (E. coli ATCC 11303) screening and HPLC confirmation methods. The screening test results, fluoroquinolones, antibacterial substances were all negative.

• 한국동물위생학회지
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• 제28권3호
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• pp.203-213
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• 2005

Oxytetracycline, tetracycline, chlortetracycline and doxycycline in honey were separated by solid phase extraction (SPE) and determined with high performance liquid chromatography (HPLC) with UV/Visible detector. Analysis was carried out using following conditions: XTerra $C_8$ column $(3.9\times150mm\;i.d. 5{\mu}m)$, mobile phase composed of 0.01M oxalic acid : methanol : acetonitrile (820 : 80 : 100, v/v/v), isocratic pump at a flow rate of 0.9 ml/min. and $50{\mu}l$ of injection volume, UV/Visible detector with wavelength of 360nm. The calibration curves of four tetracyclines showed linearity $(\gamma^2>0.999)$ at concentration range of $100\~1,000 ng/ml$. The recoveries in fortified honey represented more than $70\%$ with low coefficient of variation $(<10\%)$ for concentration range of four tetracyclines. The detection limits for oxytetracycline, tetracycline, chlortetracycline and doxycycline were 13.8, 14.6, 26.2 and 24.9ng/g in acacia honey. respectively. We also monitored tetracyclines residue in domestic honey [n : 38, acacia (20), wild flower (18) ] and foreign honey [n=22, legally distributed (13), illegally distributed (9)] using modified Charm II screening and HPLC confirmation methods. Seven of the 60 samples $(11.7\%)$ were suspect positive using modified Charm II screening test. Chlortetracycline residue was found in one foreign honey (illegally distributed) tested at concentrations of 0.22 ppm. Conclusively, for more effective control of tetracyclines used in beekeeping should be further survey for residues in honey and also national guidelines (maximum residue limit : MRL) and methods should be obligatory.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.343-347
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• 1991

Tobramycin 고생산성 변이주를 쉽고 신속하게 선별하 수 있는 screening 방법을 개발하였다. 고농도의 apramycin이 포함된 배지를 사용함으로서 nebramycin 생산성이 낮은 변이주들은 1차적으로 제거할 수 있었다. 모균주인 S. tenerbarius ATCC 17920에는 저지환을 나타내지 못하고 생산성이 향상된 변이주의 경우에만 저지환을 형성하는 strain No.23을 토양으로부터 분리하여 Ps. paucimobilis로 동정하였고 1차 선별된 변이주들 중 tobramycin 생산성이 높은 균주들을 선별하기 위한 피검균으로 사용하였다. 이러한 screening 전략으로 strain No.23에 명확히 저지환을 나타내는 변이주 58주를 얻었고, HPLC를 이용하여 각 변이주의 tobramycin 생산성을 비교 측정한 결과 모균주에 비해 3-8배 생산성이 향상되었음을 확인하였다.

• 한국식품과학회지
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• 제42권4호
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• pp.414-419
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• 2010

본 연구에서는 세 종류의 hyphenated-HPLC 기술을 활용하여 홍화씨로부터 3종의 항산화 화합물의 구조를 규명하였다. 우선 온라인 항산화 분석 장치를 통하여 홍화씨 추출물로부터 ABTS 라디칼 소거활성을 가지는 성분을 검색 및 항산화 정량을 수행한 후, 단일 물질로 분리되고, 항산화 활성을 가지는 세 가지 화합물에 대해서 구조 규명을 시도하였다. 우선 LC-NMR을 이용하여 stop-flow mode에서 이들 세 가지 화합물에 대해 $^1H$-NMR spectrum데이터를 얻은 결과 각 화합물은 8'-hydroxyarctigenin-4'-O-$\beta$-D-glucoside, N-(p-coumaroyl) serotonin, N-feruloylserotonin으로 확인되었다. 그리고 LC-ESI-MS를 활용하여 각 화합물에 대한 분자량에 대한 정보를 얻어 LC-NMR에서 규명된 화합물이 정확함을 다시 한 번 확인할 수 있었다. 본 연구에서는 기존의 탐색방법인 여러 크로마토그래피 방법이나 preparative HPLC 등을 이용하여 활성물질을 분리하고 off-line NMR, MS 등을 활용하여 구조를 규명하는 방법에 비하여, hyphenated-HPLC 방법을 활용하여 혼합물 상태인 추출물을 분리하지 않고 신속하게 단일 성분의 구조를 규명하고, 또한 각각의 성분에 대한 항산화도를 측정할 수 있다는 장점이 있음을 증명하였다. 이는 천연물 또는 식품 분야의 연구에 있어 추출물의 항산화 성분을 분석하고 그 구조를 신속 간편하게 확인할 수 있으므로 항산화 성분 탐색 및 변이 연구에 매우 유용하리라 생각된다.

• The Plant Pathology Journal
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• 제16권3호
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• pp.125-129
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• 2000

A rapid and efficient assay to determine melanin biosynthesis inhibition of Magnaporthe grisea, a causal agent of the rice blast, by chemicals was developed. Wells in 24-well plates were loaded with spore suspension of the fungus and three known melanin biosynthesis inhibitors of KC10017, tricyclazole, and carpropamid. Subsequent color changes of mycelia and culture media in the wells were observed 7 days after incubation. The wells treated with KC10017 (an inhibitor of polyketide synthesis step and/or pentaketide cyclization step) became colorless, whereas tricyclazole (an inhibitor of 1, 3, 8-trihydroxynaphthalene reductase) or carpropamid (an inhibitor of scytalone dehydratase)-treated wells exhibited red color. They did not show any inhibitory effect on fungal growth. The inhibition of reaction steps prior to 1, 3, 6, 8-tetrahydroxynaphthalene formation was easily determined by colorless medium and mycelia. However, it was impossible to distinguish between inhibition of reduction steps and inhibition of dehydration steps by colors of the cultures. It was accomplished through HPLC analysis of the melanin biosynthesis-involving pentaketide metabolites accumulated by the inhibitors. Through screening of a number of synthetic chemicals using the in vitro assay, we could find a novel chemical group of melanin biosynthesis inhibitor.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2008년도 추계학술발표회
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• pp.378-379
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• 2008

• 미생물학회지
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• 제33권1호
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• pp.38-42
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• 1997

자연계로부터 erythritol 생산균주를 선발하기 위하여 옥수수밭이나 사탕수수밭의 토양이나 자판기와 같은 당이 많은 지역으로부터 sampling하여 검색한 결과 erythritol을 생산하는 약 200여 균주를 분리할 수 있었으며 이들을 paper chromatography법으로 1차 선별한 후 HPLC를 이용하여 배양액 중의 erythritol 생산량을 측정함으로서 생산성이 가장 우수하고 부생성물이 가장 적은 KJ81균주를 최종 선발하였다. 선발된 균주의 형태학적 생리학적 특성을 조사하여 penicillium sp. KJ81로 동정하였다. 균주의 콜로니 색은 백색에서 녹색으로 변화하였고 1-3단계 분기의 분생자병과 플라스크형의 경자를 보였다.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.922-931
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• 2009

Screening-scale studies were performed with 26 fungal cultures for their ability to transform the anti-inflammatory drug meloxicam. Among the different fungi screened, a filamentous fungus, Cunninghamella blakesleeana NCIM 687, transformed meloxicam to three metabolites in significant quantities. The transformation of meloxicam was confirmed by high-performance liquid chromatography (HPLC). Based on the liquid chromatography-tandem mass spectrometry (LC-MS/MS) data, two metabolites were predicted to be 5-hydroxymethyl meloxicam and 5-carboxy meloxicam, the major mammalian metabolites reported previously. A new metabolite was produced, which is not detected in mammalian systems. Glucose medium, pH of 6.0, temperature of $27^{\circ}C$, 5-day incubation period, dimethylformamide as solvent, and glucose concentration of 2.0% were found to be suitable for maximum transformation of meloxicam when studied separately. It is concluded that C. blakesleeana can be employed for biotransformation of drugs for production of novel metabolites.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.698-706
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• 2004

$\beta$-Lactam antibiotics such as penicillin G, amoxicillin, and ampicillin were determined by a potentiometric biosensor system which exploited penicillinase immobilized on Immobilon cellulose nitrate membrane and a flat-bottomed pH electrode-as the biological component and transducer. The optimum reaction buffer for maximum sensitivity was found as 2 mM of sodium phosphate buffer (pH 7.2). The detection limit of the biosensor could be extended to 1 $\mu{M}$ of the analytes by increasing the enzyme loading for immobilization to 100 units/$m\ell$. The model samples spiked with each of the standard penicillins were measured for their biosensor responses and HPLC peak area, resulting in the relative responses of 82.1-103.5% and 79.5-106.1% for the biosensor method along with HPLC analysis, respectively. This result showed a good precision of the current biosensor method for screening the penicillin compounds.

• 한국식품과학회지
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• 제35권3호
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• pp.442-446
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• 2003

인천광역시의 일대와 강화도, 백령도, 제주도 등 한국 토양으로부터 순수분리된 200여 종의 곰팡이 균주에서 콜레스테롤 합성 저해제인 lovastatin의 생산 여부를 확인하였다. Lovastatin 생산은 rapeseed meal이 함유된 RPM 배지를 사용하였고 TLC와 HPLC를 사용하여 lovastatin의 생산을 조사하였다. 결과 200여 균주 중 9개의 균주만이 lovastatind을 생산하였고, HPLC로 확인한 결과 삼성리 퇴비 균주(ISR)에서 25.52 mg/L의 생산량을 보였다. 포자의 형태학적 구조와 18SrRNA 유전자의 염기서열 결과 삼성리 퇴비 균주는 Aspergillus sp.로 확인되었다.