• 한국식품과학회지
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• 제41권5호
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• pp.522-527
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• 2009

본 연구에서는 3-MCPD의 함량을 신뢰할 수 있는 결과값의 도출을 위하여 HFBI 유도체화 방법을 이용하였다. 3-MCPD가 검출되지 않은 양조간장에 3-MCPD를 0.020과 $0.200{\mu}g/mL$의 농도로 spiking하여 그 결과 값을 측정한 결과, 회수율이 95% 이상으로 우수하였으며 분석의 재현성 및 정밀성 또한 우수하였다. 아미노산 간장의 제조 조건 중 3-MCPD의 함량에 영향을 미칠 것으로 추정되는 조건 즉, 알칼리 처리시의 pH와 온도, 그리고 유지 시의 온도와 시간을 다양하게 하여 시료를 제조 한 후, 3-MCPD의 함량을 측정하였다. 그 결과, 알칼리 처리시의 pH와 온도가 높고, 유지 온도와 시간이 증가됨에 따라 3-MCPD의 함량이 감소되는 뚜렷한 경향을 나타내었다. 또한 알칼리 처리 온도와 유지 온도에 대한 영향보다는 알칼리 처리시의 pH가 3-MCPD의 함량에 미치는 영향이 더욱 큰 것으로 판명되었으며, 특히 pH 10.0 이상에서 알칼리 처리를 하였을 경우는 알칼리 처리 온도나 유지시간 및 유지온도 등의 다른 조건들에 상관없이 3-MCPD의 함량이 $0.020{\mu}g/g$ 이하로 현저히 낮아지는 경향을 보였다. 본 연구의 결과에 따르면 일반적인 아미노산 간장의 제조 공정 조건에 변화를 줌으로써 실질적으로 생성되는 3-MCPD의 함량을 현저하게 낮출 수 있음을 알 수 있었으며, 이러한 결과는 아미노산 간장의 3-MCPD 저감화 방안을 강구하기 위한 기초 자료로 활용할 수 있을 것으로 판단된다.

• 한국식품과학회지
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• 제28권4호
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• pp.730-735
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• 1996

마늘이 상처를 입으면 마늘중에 존재하는 alliin이 alliinase에 의해 allicin으로 분해되며 allicin은 마늘의 주된 항미생물 작용 물질로 알려져 있다. 이 성분에 의한 미생물번식 저해작용을 크게 받는 E. coli는 1%의 마늘즙액이 들어있는 TSB에서 사멸효과가 나타났으며 농도가 높을수록 사멸속도는 더욱 빨랐다. 마늘즙액에 의한 미생물생육 저해효과는 pH에 따라서도 다르게 나타나는데 pH 7.2에 비해 5.2와 6.2에서 저해작용이 강하게 나타났다. 초기 접종균수가 $10^{6}\;CFU/ml 이상일 때는 번식에 대한 저해효과가 나타나지 않았으나 $10^{5}\;CFU/ml 이하일 때는 저해효과가 나타나서 항미생물 작용에 대한 초기 미생물 수도 중요한 변수였다. 유리 SH기를 가진 cysteine이나 glutathione을 첨가하면 마늘즙액의 번식 저해효과로부터 E. coli를 보호하였다. 결과적으로 E. coli에 대한 마늘즙액의 번식 저해효과는 마늘즙액의 농도뿐만 아니라 pH, cystein이나 glutathione같은 SH화합물의 존재여부, 접종균수에 의해서 영향을 받음을 알 수 있었다.

• 한국축산식품학회지
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• 제28권5호
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• pp.587-595
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• 2008

본 연구는 국내 각 지역의 목장에서 수거한 원유에서 분리된 젖산균을 대상으로 10% 환원탈지유에 $37^{\circ}C$에서 pH 4.4에 도달할 때까지 배양한 다음 각각에서 얻어진 유청으로 ACE 저해율을 측정한 결과 88.6%인 우수한 균주를 선발하였다. 선정된 균은 Gram 양성, rod형태의 homo균이며, 당 발효실험과 16S rRNA 분석결과 Lactobacillus zeae로 판명되었고, Lactobacillus zeae RMK354로 명명하였다. 발효유에 적합한 starter인지 확인하기 위해 생리적 특성을 조사하였다. L. zeae RMK354는 배양온도 $40^{\circ}C$에서 빠른 생장을 보였고, pH4.3에 도달하는데 10시간이 소요되었다. 16종의 항생제 중 polymyxin B와 vancomycin에 대해 내성이 높았으며, 효소활성실험에서 esterase와 leucine arylamidase의 활성도가 높았다. 담즙에 대한 내성이 있는 것으로 나타났으며, pH 내성 실험결과 pH 2에서 큰 변화가 없음에 따라 내신성이 있었다. 항균력 시험에서는 Escherichia coli와 Staphylococcus aureus에 대해 억제력이 없었으나 Salmonella typhimurium에 대해 60.0%의 항균력을 보였다. 이러한 결과를 토대로 ACE 억제활성능이 우수한 기능성 발효유 제품의 스타터로 L. zeae RMK354는 적합하다고 할 수 있다.

• 한국농림기상학회지
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• 제18권3호
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• pp.120-126
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• 2016

본 연구는 유사한 입지에서 생육한 소나무와 굴참나무 임분의 토양 이산화탄소($CO_2$)와 이들 방출에 영향을 미치는 환경요인인 토양 온도, 토양 수분, 토양 pH, 전기전도도, 토양 유기탄소 농도 등을 2015년 3월부터 2016년 2월까지 1년 동안 조사하였다. 토양 $CO_2$ 방출량의 월별 변화는 두 임분 사이에 차이가 있어 하절기인 6월과 7월의 경우, 굴참나무 임분이 소나무 임분에 비해 유의적으로 높았으나, 타 계절은 차이가 없었다. 연 평균 토양 $CO_2$ 방출량의 경우, 굴참나무 임분이 $2.27{\pm}0.22{\mu}mol\;m^{-2}s^{-1}$로 소나무 임분의 $1.63{\pm}0.12{\mu}mol\;m^{-2}s^{-1}$ 에 비해 높게 나타났으며, 연 평균 토양 온도와 토양 수분함량도 굴참나무 임분이 소나무 임분에 비해 높았다. 토양 환경요인 중 토양 온도와 토양 $CO_2$ 방출량은 지수함수 관계(P<0.05)가 있었으며, $Q_{10}$ 값의 경우, 굴참나무 임분이 3.35로 소나무 임분 2.72에 비해 높아 토양 온도 상승 시, 굴참나무 임분의 토양 $CO_2$ 방출량이 소나무 임분에 비해 더 크게 증가하는 것으로 나타났다.

• 한국어병학회지
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• 제6권1호
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• pp.1-10
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• 1993

발병한 양식 메기로 부터 vibrio속 균주를 분리하였다. 분리된 균주는 생물학적 생화학적 특성에 기초하여 동정한 결과 V. ordalii로 동정 되었다. 분리균은 glucose, lactose, maltose 와 salicine으로 부터 산을 생산 하였으며, arabinose, galactose, inocitol과 xylose는 이용하지 못하였다. 분리된 V. ordalii를 각각 KL-1, KL-2라 명명하였다. KL-l과 KL-2는 생리학적 특성이 유사하였다. 즉, pH 5-10, NaCl 0%~6.0%에서 발육하였으며, 또한 NaCl 7.0%, pH 10이상 그리고 pH5이하에서는 발육하지 않았다. KL-1 균주를 건강한 메기에 인공 감염시킨 결과 양식장에서 발병된 증상과 동일한 출혈성 궤양이 유발되었다. 감염 24시간 후에 나타난 흙은 반점은 접종 부위 주변에서 부터 확장되기 시작했으며, 감염 120시간 후부터는 배지느러미 부위까지 궤양이 확장되었다. 각각 온도에 따른 실험에서는 $25^{\circ}C$에서 폐사율이 70%로 나타났다. 약제 감수성 시험에서 KL-1 과 KL-2 균주는 모두 GM, K, N, S와 SxT에 감수성을 나타내었으나, CF 및 $L_2$와 VA에는 저항성을 나타내었다.

• Journal of Pharmaceutical Investigation
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• 제35권3호
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• pp.137-142
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• 2005

A rapid, selective and sensitive reversed-phase HPLC method for the determination of glipizide in human serum was validated and applied to the pharmacokinetic study of glipizide. Glipizide and internal standard, tolbutamide, were extracted from human serum by liquid-liquid extraction with benzene and analyzed on a Nova Pak $C_{18}\;60{\AA}$ column with the mobile phase of acetonitrile-potassium dihydrogen phosphate (10 mM, pH 3.5) (4:6, v/v). Detection wavelength of 275 nm and flow rate of 0.7 ml/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^3$ factorial design using a fixed glipizide concentration (500 ng/ ml) with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 10-1000 ng/ml with correlation coefficient greater than 0.999. The lower limit of quantitation using 0.5 ml of serum was 10.0 ng/ml, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 82.6 to 105.0% for glipizide with overall precision (% C.V.) being 1.13-13.20%. The percent recovery for human serum was in the range of 85.2 93.5%. Stability studies showed that glipizide was stable during storage, or during the assay procedure in human serum. The peak area and retention time of glipizide were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of glipizide in human serum samples for the pharmacokinetic studies at three different laboratories, demonstrating the suitability of the method.

• Journal of Pharmaceutical Investigation
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• 제35권6호
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• pp.423-429
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• 2005

A selective and sensitive reversed-phase HPLC method for the determination of fenoprofen in human serum was developed, validated, and applied to the pharmacokinetic study of fenoprofen calcium. Fenoprofen and internal standard, ketoprofen, were extracted from human serum by liquid-liquid extraction with diethyl ether and analyzed on a Luna C18(2) column with the mobile phase of acetonitrile-3 mM potassium dihydrogen phosphate (32:68, v/v, adjusted to pH 6.6 with phosphoric acid). Detection wavelength of 272 nm and flow rate of 0.25 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed fenoprofen concentration $(2\;{\mu}g/mL)$ with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of $0.05-100\;{\mu}g/mL$ with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was $0.05\;{\mu}g/mL$, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 92.27 to 109.20% for fenoprofen with overall precision (% C.V.) being 5.51-11.71 %. The relative mean recovery of fenoprofen for human serum was 81.7%. Stability (freeze-thaw, short and long-term) studies showed that fenoprofen was not stable during storage. But, extracted serum sample and stock solution were allowed to stand at ambient temperature for 12 hr prior to injection without affecting the quantification. The peak area and retention time of fenoprofen were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of fenoprofen in human serum samples for the pharmacokinetic studies of orally administered Fenopron tablet (600 mg as fenoprofen) at three different laboratories, demonstrating the suitability of the method.

• 한국토양비료학회지
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• 제48권2호
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• pp.125-131
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• 2015

Phenyllactic acid (PLA) which is known as antimicrobial compound can be synthesized through the reduction of phenylpyruvic acid (PPA) by lactate dehydrogenase (LDH) of lactic acid bacteria (LAB). LAB producing PLA was isolated from Korea Kimchi and identified to Lactobacillus plantarum SJ21 by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. plantarum SJ21 was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against four fungal pathogens (Rhizoctonia solani, Aspergillus oryzae, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23mM in CFS when L. plantarum SJ21 was grown in MRS broth containing 5mM PPA for 16 h. PLA production also could be promoted by the supplement of PPA and phenylalanine in MRS broth, but inhibited by the supplement of 4-hydroxyphenylpyruvic acid and tyrosine as precursors. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. plantarum SJ21 with average growth inhibitions ranging from 27.32% to 69.05% (p<0.005), in which R. solani was the most sensitive to 69.05% and followed by B. cinerea, C. aculatum, and A. oryzae. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range from $0.35mg\;mL^{-1}$ (2.11 mM) to $0.7mg\;mL^{-1}$ (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens was not affected by heating or protease treatment. However, pH modification in CFS to 6.5 caused an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS were caused by acidic compounds like PLA or organic acids rather than proteins or peptides molecules.

• Journal of Pharmaceutical Investigation
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• 제36권1호
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• pp.45-51
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• 2006

A rapid, selective and sensitive reversed-phase HPLC method for the determination of dipyridamole in human serum was developed, validated, and applied to the pharmacokinetic study of dipyridamole. Dipyridamole and internal standard, loxapine, were extracted from human serum by liquid-liquid extraction with diethyl ether and analyzed on a Nova Pak $C_{I8}$ column with the mobile phase of 40 mM ammonium acetate:methanol:acetonitrile (35:35:30)(v/v/v, pH 7.8). Detection wavelength of 280 nm and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^3$ factorial design using a fixed dipyridamole concentration (50 ng/mL) with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 2-2000 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 2 ng/mL, which was sensitive enough for pharmacokinetic studies of dipyridamole. The overall accuracy of the quality control samples ranged from 103.94 to 105.86% for dipyridamole with overall precision (% C.V.) being 4.60-11.49%. The relative mean recovery of dipyridamole for human serum was 97.64%. Stability studies showed that dipyridamole was stable during storage, or during the assay procedure in human serum. The peak area and retention time of dipyridamole were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of dipyridamole in human serum samples for the pharmacokinetic studies of orally administered Dimor tablet (75 mg as dipyridamole) at three different laboratories, demonstrating the suitability of the method.

• Journal of Pharmaceutical Investigation
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• 제36권1호
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• pp.23-29
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• 2006

A rapid, selective and sensitive reversed-phase HPLC method for the determination of promethazine in human serum was developed, validated, and applied to the pharmacokinetic study of promethazine. Promethazine and internal standard, chlorpromazine, were extracted from human serum by liquid-liquid extraction with n-hexane containing 0.8% isopropanol and analyzed on a Capcell Pak CN column with the mobile phase of acetonitrile-0.2 M potassium dihydrogen phosphate (42:58, v/v, adjusted to pH 6.0 with 1 M NaOH). Detection wavelength of 251 nm and flow rate of 0.9 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed promethazine concentration (10 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 1-40 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was 1 ng/mL, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 96.15 to 105.40% for promethazine with overall precision (% C.V.) being 6.70-11.22%. The relative mean recovery of promethazine for human serum was 63.54%. Stability (freeze-thaw and short-term) studies showed that promethazine was stable during storage, or during the assay procedure in human serum. However, the storage at $-80^{\circ}C$ for 4 weeks showed that promethazine was not stable. Extracted serum sample and stock solution were not allowed to stand at ambient temperature for 12 hr prior to injection. The peak area and retention time of promethazine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of promethazine in human serum samples for the pharmacokinetic studies of orally administered Himazin tablet (25 mg as promethazine hydrochloride) at three different laboratories, demonstrating the suitability of the method.