• Proceedings of the PSK Conference
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• 2003.04a
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• pp.283.1-283.1
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• 2003

This study was designed to develop and validate an isocratic reversed phase high performance liquid chromatographic(HPLC) method for the quantitation of sobrerol in drug preparations, and obtain the data pool that can be used in the revision of pharmacopoeia. The separation of sobrerol and the other compounds (S-carboxymethylcysteine, acetaminophen, methyl paraben, propyl paraben, and sobrerol degradants) was achieved in a C18 column with an acetonitrile-methanol-water(24.5:10.5:65.0) mobile phase. (omitted)

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.544-544
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• 2003

We investigated the inhibitory effect of whitening materials with growth factor or alone on melanomas derived from Human (B-16) and mouse (SK-MEL-31) using melanin content. Melanin content was determined by the absorbance value at 470nm per cells. we used the growth factors known as activators of Adenylate cyclase, Protein kinase C and tyrosine kinase pathway separately. In addition, we compared the action of UV-induced with non-biological growth factor with whitening materials in melanomas derived from Human and mouse. The results showed that the aspect of inhibitory effect of whitening materials on B16 and SK-MEL-31 was not different. And, the action of each growth factor involved in the differentiation and proliferation of melanoma on the inhibition of melanogenesis in B-16 and SK-MEL-31 using whitening agents showed no difference. Also, The action of UV -induced and non-biological growth factors didn't exhibit different pattern on the effect of whitening agent in B-16 and SK-MEL-31.

• Toxicological Research
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• v.33 no.1
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• pp.43-48
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• 2017

With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxic potential of a given substance indirectly. For this reason, a standard ROS assay (ROS assay) was developed and validated and provides an alternative method for phototoxicity evaluation. However, negative substances are over-predicted by the assay. Except for ultraviolet A (UVA), other UV ranges are not a major factor in causing phototoxicity and may lead to incorrect labeling of some non-phototoxic substances as being phototoxic in the ROS assay when using a solar simulator. A UVA stimulator is also widely used to evaluate phototoxicity in various test substances. Consequently, we identified the applicability of a UVA simulator to the ROS assay for photoreactivity. In this study, we tested 60 pharmaceutical substances including 50 phototoxins and 10 non-phototoxins to predict their phototoxic potential via the ROS assay with a UVA simulator. Following the ROS protocol, all test substances were dissolved in dimethyl sulfoxide or sodium phosphate buffer. The final concentration of the test solutions in the reaction mixture was 20 to $200{\mu}M$. The exposure was with $2.0{\sim}2.2mW/cm^2$ irradiance and optimization for a relevant dose of UVA was performed. The generation of ROS was compared before and after UVA exposure and was measured by a microplate spectrophotometer. Sensitivity and specificity values were 85.7% and 100.0% respectively, and the accuracy was 88.1%. From this analysis, the ROS assay with a UVA simulator is suitable for testing the photoreactivity and estimating the phototoxic potential of various test pharmaceutical substances.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.479-479
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• 2003

We investigated the tyrosinase inhibitory effect using whitening materials such as arbutin, ethyl ascorbyl ether, glabridin, kojic acid, magnesium ascorbyl phosphate and ascorbic acid. Tyrosinase inhibition rate were determined varying the enzyme concentration, reaction time, reaction temperature and pH. The optimal conditions to measure the inhibitory efficacy were as follows. : enzyme concentration 1,500 or 2,000IU/mL, reaction time 15min(for the enzyme concentration 1,500 IU/mL) and l0min(for the enzyme concentration 2,000IU/mL), reation temperature 42$^{\circ}C$, pH 6.5. Under these conditions $IC_{50}$/ of arbutin, ethyl ascorbyl ether, glabridin, kojic acid, magnesium ascorbyl phosphate and ascorbic acid were calculated. In the case of magnesium ascorbyl phosphate, the inhibitory effect of tyrosinase was very low and the $IC_{50}$/ of magnesium ascorbyl phosphate could not be calculated. Other five materials showed good inhibitory effect of tyrosinase and can be used for the whitening materials.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.181-187
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• 2013

Identification of main ingredients in starches has been investigated using physicochemical analysis method mainly. However, physicochemical properties such as particle size have limitations in determining the differences among mixed starches. Therefore, we developed a molecular biological method to identify materials used in starch, as a sample, 11 kinds of starches including sweet potato starch, potato starch, corn starch, and tapioca starch. DNeasy plant mini kit, magnetic DNA purification system, and CTAB methods were used to extract DNA from samples. After gene extraction, whole genome amplification (WGA) was performed to amplify the extracted DNA. Species-specific primers were used as followings: ib-286-F/ib-286-R (105 bp), Pss 01n-5'/Pss 01n-3' (216 bp), SS11b 3-5'/SS11b 3-3' (114 bp), and SSRY26-F/SSRY26-R (121 bp) gene for sweet potato, potato, corn, and tapioca, respectively. In this study, we could confirm the main ingredients using WGA and PCR method.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.403.3-404
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• 2002

Dimethyl phthalate(DMP). diethyl phthalate(DEP), di-n-butyl phthalate (DBP). butyl benzyl phthalate(BBP). bis(2-ethylhexyl)phthalate(DEHP) and di-n-octyl phthalate(DOP) in lotions was determined by gas chromatography. and benzyl benzoate was used as the intermal standard. The separation of the six phthalates and internal standard was optimized, and the optimal analytical conditions were as follows: column. DB-1701 (I.D. 0.25mm): mobile phase. helium: oven temperature 20$0^{\circ}C$ (10 min) ${\rightarrow}10^{\circ}C$/min ${\rightarrow}260^{\circ}C$/min(30min), injector temperature 23$0^{\circ}C$, detector temperature 28$0^{\circ}C$. (omitted)

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1552-1558
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• 2021

The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic Escherichia coli (ETEC) during the fermentation of kimchi at two temperatures using high-throughput sequencing. There were no differences in pH between the control group, samples not inoculated with ETEC, and the ETEC group, samples inoculated with ETEC MFDS 1009477. The pH of the two groups, which were fermented at 10 and 25℃, decreased rapidly at the beginning of fermentation and then reached pH 3.96 and pH 3.62. In both groups, the genera Lactobacillus, Leuconostoc, and Weissella were predominant. Our result suggests that microbial communities during kimchi fermentation may be affected by the fermentation parameters, such as temperature and period, and not enterotoxigenic E. coli (ETEC).

• Toxicological Research
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• v.28 no.2
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• pp.73-79
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• 2012

While the ability to develop nanomaterials and incorporate them into products is advancing rapidly worldwide, understanding of the potential health safety effects of nanomaterials has proceeded at a much slower pace. Since 2008, Korea Food and Drug Administration (KFDA) started an investigation to prepare "Strategic Action Plan" to evaluate safety and nano risk management associated with foods, drugs, medical devices and cosmetics using nano-scale materials. Although there are some studies related to potential risk of nanomaterials, physical-chemical characterization of nanomaterials is not clear yet and these do not offer enough information due to their limitations. Their uncertainties make it impossible to determine whether nanomaterials are actually hazardous to human. According to the above mention, we have some problems to conduct the human exposure risk assessment currently. On the other hand, uncertainty about safety may lead to polarized public debate and to businesses unwillingness for further nanotechnology investigation. Therefore, the criteria and methods to assess possible adverse effects of nanomaterials have been vigorously taken into consideration by many international organizations: the World Health Organization, the Organization for Economic and Commercial Development and the European Commission. The object of this study was to develop risk assessment principles for safety management of future nanoproducts and also to identify areas of research to strengthen risk assessment for nanomaterials. The research roadmaps which were proposed in this study will be helpful to fill up the current gaps in knowledge relevant nano risk assessment.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.123-123
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• 2004

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.157.1-157.1
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• 2001