• 한국식품영양학회지
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• 제11권3호
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• pp.347-353
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• 1998

토양에서 분리한 Streptomyces lydicus YSK-681이 생산하는 메치실린내성 황색 포도상구균에 유효한 항생물질을 정제하여 물리화학적 특성을 주사하였다. 물질정제는chloroform으로 추출한 후 silica gel column chromatography, Si ODS, GPC HPLC순으로 진행하였다. FAB MS의 분자량 측정결과 m/z 1022.4와 1036.4(M+H)+의 두 개의 피크가 분석되었으며, NMR 분석에서는 -OH와 leucine으로 추정되는 관능기가 조사되었다. 정제된 항생물질의 MIC는 그람 양성군에 대해서 1~32 $\mu\textrm{g}$/$m\ell$, 그람 음성군과 효모에서는 125 $\mu\textrm{g}$/$m\ell$ 이상이었다. 임상에서 분리된 129개의 MRSA에 대한 MIC는 8 $\mu\textrm{g}$/$m\ell$이었으며, 암세포인 P388, HeLa, S180에 대한 세포 독성은 없었다.

• Asian Journal of Atmospheric Environment
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• 제11권4호
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• pp.283-299
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• 2017

An analytical method using high-performance liquid chromatography (HPLC) with fluorescence (FL) detection was developed for simultaneously analyzing 10 polycyclic aromatic hydrocarbons (PAHs) and 18 nitro-derivatives of PAHs (NPAHs). The two-dimensional HPLC system consists of an on-line clean-up and reduction for NPAHs in the 1st dimension, and separation of the PAHs and the reduced NPAHs and their FL detection in the 2nd dimension after column-switching. To identify an ideal clean-up column for removing sample matrix that may interfere with detection of the analytes, the characteristics of 8 reversed-phase columns were evaluated. The nitrophenylethyl (NPE)-bonded silica column was selected because of its shorter elution band and larger retention factors of the analytes due to strong dipole-dipole interactions. The amino-substituted PAHs (reduced NPAHs), PAHs and deuterated internal standards were separated on polymeric octadecyl-bonded silica (ODS) columns and by dual-channel detection within 120 min including clean-up and reduction steps. The limits of detection were 0.1-9.2 pg per injection for PAHs and 0.1-140 pg per injection for NPAHs. For validation, the method was applied to analyze crude extracts of fine particulate matter ($PM_{2.5}$) samples and achieved good analytical precision and accuracy. Moreover, the standard reference material (SRM1649b, urban dust) was analyzed by this method and the observed concentrations of PAHs and NPAHs were similar to those in previous reports. Thus, the method developed here-in has the potential to become a standard HPLC-based method, especially for NPAHs.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.679-687
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• 2018

Korean red pine (Pinus densiflora) is one of the major Pinus species in Korea. Red pine bark is removed prior to the chipping process in the wood industry and discarded as waste. However, red pine bark contains a considerable amount of naturally occurring phenolics, including flavonoids, and therefore may have a variety of biological effects. In this study, we investigated if Korean red pine bark extract (KRPBE) could protect neuronal PC-12 cells from oxidative stress and inhibit cholinesterase activity. Analysis of reversed-phase high-performance liquid chromatography results revealed four phenolics in KRPBE: vanillin, protocatechuic acid, catechin, and taxifolin. The total phenolic and flavonoid contents of KRPBE were 397.9 mg gallic acid equivalents/g dry weight (DW) and 248.7 mg catechin equivalents/g DW, respectively. The antioxidant capacities of KRPBE measured using ABTS, DPPH, and ORAC assays were 697.3, 521.8, and 2,627.7 mg vitamin C equivalents/g DW, respectively. KRPBE and its identified phenolics protected against $H_2O_2$-induced oxidative cell death in a dose-dependent manner. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission in synaptic clefts, were inhibited by treatment with KRPBE and its identified phenolics. Taken together, these results suggest that KRPBE and its constituent antioxidative phenolics are potent neuroprotective agents that can maintain cell viability under oxidative stress and inhibit cholinesterase activity.

• Nutritional Sciences
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• 제1권1호
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• pp.22-28
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• 1998

Plasma concentrations of Vitamins E and A were measured in 15 non-insulin dependent Korean female subjects and 15 age-matched normal subjects using reversed-phase high-performance liquid chromatography. No differences were found in plasma Vitamin E concentrations between the 2 groups. Plasma Vitamin A concentrations were higher in subjects with non-insulin dependent diabetes melitus (NIDDM). The effects were evaluated of 4 weeks of daily supplementation of 400 mg Vitamin E on plasma levels of these two vitamins. In addition, the effects were observed for Vitamin E supplementation on oxidative stress and immune-related compound productions in non-insulin dependent diabetic patients and control subjects. After treatment with Vitamin E, plasma Vitamin E concentrations were significantly elevated in both groups. Basal plasma thiobarbituric acid reactive substances (TBABS) were identical, and a decreased level of TBARS caused by Vitamin E was observed only in the diabetic group (0.02739$\pm$0.0024 versus 0.01814$\pm$0.0008 nmols malondialdehyde equivalents/dl plasma ; p<0.05). The basal and after-treatment levels of immunoglobulins A, G, M were identical in control and diabetic groups, indicating that Vitamin E did not appear to alter gross humoral responses in this study. However, elevation of Complement 3 ($C_3$) was noticed due to Vitamin E supplementation, revealing a possible effect of vitamin E on one aspect of humoral immunity, Furthermore, an increase in prostaglandin E_2 ($PGE_2$) levels in diabetic patients was normalized by Vitamin E supplementation. This suggests indirectly that the depressed cell-mediated response due to elevated $PGE_2$ could be normalized. For the definitive antioxidant intake recommendations for prevention and treatment of adverse effects of non-insulin dependent diabetes, evidence from intervention trials like this study should be collected. The present data suggests that Vitamin E may oxen some protective effects against oxidative damage and might have beneficial effects of partial immune-stimulation.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2425-2430
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• 2015

Clinical resistance to chemotherapeutic agents is one of the major hindrances in the treatment of human cancers. EHZ2 is involved in drug resistance and is overexpressed in drug-resistant cancer cell lines. In this study, we investigated the effects of EHZ2 on cisplatin -resistance in A549/DDP and AGS/DDP cells. EHZ2 mRNA and protein were found to be significantly overexpressed in A549/DDP and AGS/DDP cells, compared to parental cells. EHZ2 siRNA successfully silenced EHZ2 mRNA and protein expression. Proliferation was inhibited and drug resistance to cisplatin was improved. Flow cytometry showed that silencing of EHZ2 arrested A549/DDP and AGS/DDP cells in the G0/G1 phase, increasing apoptosis, rh-123 fluorescence intensity and caspase-3/8 activities. Silencing of EHZ2 also significantly reduced the mRNA and protein expression levels of cyclin D1 and MDR1,while up-regulating p15, p21, p27 and miR-218 in A549/DPP cells. Furthermore, silencing of EHZ2 also significantly increased the expression level of tumor suppressor factor miR-218. We also found down-regulating EHZ2 expression increased methylation in A549/DDP and AGS/DDP cells. This study demonstrates that drug resistance can be effectively reversed in human cisplatin-resistant lung and gastric cancer cells through delivery of siRNAs targeting EHZ2.

• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.375-381
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• 2005

A rapid and specific high-performance liquid chromatographic method was developed and validated for the simultaneous determination of prostaglandin $E_{1}\;(PGE_{1})$ and prostaglandin $E_{1}$ ethyl ester $(PGE_{1}-EE)$ in hairless mouse skin homogenate. The sample treatment procedure involved deproteination and precipitation by acetonitrile. $PGE_{1}$ and $PGE_{1}-EE$ in supernatant were separated in a reversed-phase C18 column without being interfered by other components present in hairless mouse skin homogenate. 9-Anthracenecarboxylic acid was used as an internal standard. The retention times of $PGE_{1}$, 9-anthracenecarboxylic acid and $PGE_{1}-EE$ were, 4.5, 9.5 and 18.0 min, respectively. The assay showed linearity from 1 to $40\;{\mu}g/ml$ for both $PGE_{1}$ and $PGE_{1}-EE$. Precision expressed as RSD ranged from 2.3 to 14.1 % for $PGE_{1}$ and 1.6 to 11.0% for $PGE_{1}-EE$. Accuracy ranged from 100.5 to 119.6 % for $PGE_{1}$ and from 98.0 to 103.7% for $PGE_{1}-EE$. This method was employed successfully to follow the time course of concentrations of $PGE_{1}$ and $PGE_{1}-EE$ in hairless mouse skin homogenate for stability study.

• Journal of Microbiology and Biotechnology
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• 제27권6호
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• pp.1090-1097
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• 2017

Rhus verniciflua Stokes (RVS), an herbal medicine found in East Asia, was extracted and further fractionated to investigate its antioxidant capacity and neuroprotective effects. The RVS ethyl acetate (EtOAc) fraction had the highest level of total phenolics and antioxidant capacity among all solvent fractions tested. Pretreatment of PC-12 cells with the EtOAc fraction effectively attenuated $H_2O_2$-induced oxidative damage. Furthermore, the EtOAc fraction significantly attenuated caspase-3 activity, resulting in inhibition of $H_2O_2$-induced apoptosis. We identified and quantified fustin, sulfuretin, and butein in the EtOAc fraction using accurate mass quadrupole time-of-flight mass spectrometry and reversed-phase high-performance liquid chromatography. The intracellular antioxidant capacity and superoxide dismutase (SOD) activity were significantly increased in PC-12 cells treated with the EtOAc fraction and with individual flavonoids. When cells were pretreated with the EtOAc fraction or individual flavonoids and then co-incubated with diethyldithiocarbamic acid (an inhibitor of SOD activity), cell viability against $H_2O_2$-induced oxidative stress was attenuated. These results suggest that the RVS EtOAc fraction and its flavonoid constituents protect PC-12 cells against $H_2O_2$-induced neurotoxicity through their antioxidant properties.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.717-722
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• 2015

감귤류의 과일 내에 포함된 것으로 알려진 d-limonene 성분은 정유 성분을 추출하여 분리하는 방법으로 얻을 수 있다. 연속 증류 추출법 중 하나인 Soxhlet 추출법을 사용하여 감귤 껍질의 정유 성분을 추출한 후, 역상 HPLC를 통해 정량분석을 하였다. 추출용매의 끓는점과 극성도가 수율에 주는 영향을 알아보기 위해 에탄올, n-헥산, 석유에테르 3가지 용매를 추출 용매로 사용하였다. $120^{\circ}C$에서 각각의 용매를 1, 2, 4시간 동안 추출했을 때의 시료를 얻어 총 9가지 시료를 분석하였다. 역상 HPLC에서 정량분석을 한 결과, 세 가지 용매 모두 2시간 동안 추출했을 때 d-limonene의 함유량이 가장 많았으며, 이 때 감귤 껍질 1 g당 함유량은 7.77 mg(에탄올), 0.49 mg(n-헥산), 0.28 mg(석유에테르)였다. 에탄올을 사용했을 때 수율이 가장 높은 것으로 보아 용매의 극성도가 끓는점보다 추출 효율에 더 큰 영향을 미치는 것을 알 수 있었다.

• 대한본초학회지
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• 제31권3호
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• pp.29-35
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• 2016

Objectives : Ijung-tang (IJT) is a traditional herbal formula and has been used to treat digestive diseases such as abdominal pain, vomiting, and diarrhea. IJT consists of four herbal medicines, Ginseng radix, Atractylodis rhizoma alba, Zingiberis rhizoma, and Glycyrrhizae radix et rhizoma, containing various bioactive compounds. Quality assesment of IJT preparations was performed by analytical method for determining marker compounds.Methods : Determination of seven marker compounds in IJT preparations was quantitatively conducted by high-performance liquid chromatography equipped with a diode-array detector. The marker compounds were separated on a reversed-phase C18 column and the analytical method was successfully validated. Chemometric analysis was performed to compare IJT water extracts and commercial IJT granules.Results : Limit of detection and limit of quantification values were in the ranges of 0.093-2.649 μg/mL and 0.283-8.027 μg/mL, respectively. Precisions were 0.30-3.87% within a day and 0.23-2.35% over three consecutive days. Recoveries of the marker compounds ranged from 87.35-107.05%, with relative standard deviation (RSD) values < 6.15%. Repeatabilities were < 1.20% and < 1.71% of RSD value for retention time and absolute peak area, respectively. The results from quantitative analysis showed that the quantities of seven marker compounds of IJT samples varied, as were found in principal component analysis and hierarchical clustering analysis.Conclusions : The analytical method developed in the present study was precise and reliable to simultaneously determine marker compounds of IJT. Therefore, it can be used for the quality assessment of IJT preparations.

• 대한본초학회지
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• 제30권4호
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• pp.11-20
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• 2015

Objectives : Ongyeong-tang (OGT) is a traditional herbal formula used to cure gynaecological disorders. OGT consists of 12 herbal medicines containing various bioactive components. Therefore, the development of suitable analytical method for the marker compounds is necessary for the quality control of OGT. Methods : Determination of the 18 marker compounds in OGT preparations was quantitatively performed by high-performance liquid chromatography-photodiode array detection analysis. The marker compounds were separated on a reversed-phase C ₁₈ column and the analytical method was successfully validated, which was applied to compare OGT extracts from laboratory preparation and commercial OGT granules. Results : Limit of detection and limit of quantification values were in the ranges of $0.001-0.016{\mu}g/mL$ and $0.003-0.047{\mu}g/mL$, respectively. Precision was 0.03-3.71 % within a day and 0.03-3.81 % over four consecutive days. Recovery of marker compounds ranged from 90.63-108.26 %, with relative standard deviation (RSD) values < 4.0 %. Reproducibility was < 2.5 % of the RSD value. The 18 marker compounds were stable within 16 h at $10^{\circ}C$, with the RSD value < 3.5 %. Quantitative analysis results showed that the quantities of the 18 marker compounds varied among OGT samples. Pearson coefficient evaluation and principal component analysis demonstrated that an OGT water extract produced by a laboratory method clearly differed from commercial OGT granules. Conclusions : The developed analytical method was simple, precise, and reliable. Therefore, it can be used for the quality assessment of OGT preparations.