• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.885-890
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• 2010

This study was conducted to confirm the application as ingredients of cosmetics through an examination of the function for anti-oxidant activity of the fraction isolated from Pyrus ussuriensis leaves. The dried leaf of Pyrus ussuriensis were extracted with acetone-$H_2O$ (6:4, v/v), concentrated and fractionated with the upper layer of acetone on a separatory funnel. Each fraction was freeze dried, then a portion of acetone soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol as eluents and also used the MIC-gel using a series of aqueous methanol as developing solvent. The isolated compounds were identified by silica-gel TLC. The concentration of total phenolic compound of Pyrus ussuriensis acetate soluble fraction was high, 914 mg/g. The results obtained from the analyses of the anti-oxidanat effects of Pyrus ussuriensis acetate fraction can be summarized as follows: In the result of DPPH scavenging radical activity, Pyrus ussuriensis acetate soluble fraction showed more than 80% at 100 ppm. SOD-like activity of one of Pyrus ussuriensis acetate soluble fractions was 77% at 1000 ppm. Xanthine oxidase inhibition of Pyrus ussuriensis acetate soluble fraction was 38% at 100 ppm. From these results, we confirmed that acetate fraction of Pyrus ussuriensis has a great potential as a natural ingredients with a natural antioxidant and antimicrobial source.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.14-18
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• 2009

This study was to determine the inhibitory effect against food borne pathogens of ethanol and water extracts from leaf, stem and root of Orostachys japonicus. On the paper disc assay, no detectable bactericidal activity in the water extracts from leaf, stem and root of Orostachys japonicus and ethanol extracts form stem and root of Orostachys japonicus was shown. However, ethanol extract of Orostachys japonicus leaf showed the highest antimicrobial activity. Minimum inhibitory concentration (MIC) of ethanol extracts was determined to range from 0.05 to 0.1% in leaf of Orostachys japonicus against gram positive bacteria and yeast. Antimicrobial activity of ethanol extracts was stable by heating at $121^{\circ}C$ for 15 min, and not affected by pH $2{\sim}10$ except for B. subtilis. These findings suggest ethanol extract from leaf of Orostachys japonicus may be useful as natural preservative.

• Journal of Life Science
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• v.30 no.8
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• pp.688-694
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• 2020

In a previous study, the total phenolic content in ethanol extracts of medicinal plants that naturally grow on Jeju Island were analyzed with the extracts of Raphiolepsis indica leaf found to have the highest. The current study was carried out to evaluate the total flavonoid content, radical-scavenging activity, and the protective effect of R. indica extracts and solvent fractions on oxidative stress in HaCaT keratinocytes. More specifically, total flavonoid content and 2-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical-scavenging activity were measured to assess anti-oxidative activity, and protective effects against hydrogen peroxide (H₂O₂) were determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay on the HaCaT cells. Of the various fractions analyzed, the ethyl acetate extract of R. indica showed the highest total flavonoid content (149.13 mg/g extracts) and the lowest remaining ABTS. In addition, the ethyl acetate fraction was significantly more resistant against H₂O₂ than the negative control. Our results therefore suggest that an ethyl acetate fraction of R. indica protects HaCaT cells against oxidative stress and could prove useful for developing functional cosmetic materials.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.583-590
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• 2012

The HF (Hollow fiber) extraction method was optimized to analysis seven species of pesticides in aqueous sample and analyzing samples by GC/MS. Hollow fiber extraction showed good efficiency when it was conducted under these conditions: organic solvent was toluene and agitation speed was 1200 rpm. The 15% concentration of NaCl was optimized when it was experimented between 5% and 25%. The equilibrium time was determined at 15 minutes. The pH 5 showed the best effect on the extraction efficiency. The linearities of calibration curves of seven species were good with correlation of regression ($r^2$) over 0.995 when they were experimented over a concentration range of $5{\mu}g/L$ to $50{\mu}g/L$. The analytical data exhibited the detection of limits (LODs) range of $0.37{\mu}g/L$ to $1.23{\mu}g/L$ and the limit of quantification (LOQs) range of $1.19{\mu}g/L$ to $3.91{\mu}g/L$. The optimized HF-LPME extraction method provides a simple and effective preparation and requires small amount of organic solvents and samples compared to conventional pre-treatment methods.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.523-530
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• 1999

Acrylic pressure-sensitive adhesive has been made utilizing organic solvents, but nowadays it is made by solvent-free system due to environmental problems. In this study, emulsion polymerization were carried out at $40^{\circ}C$ with methacrylic acid(MAA), n-butyl acrylate(n-BA) and 2-ethylhexyl acrylate(2-EHA) as monomers in the presence of anionic(sodium dodecyl sulfate, SDS) and nonionic(ethylene oxide types) surfactant mixtures. The overall conversion of the polymerization reaction in a mixed surfactant system was found to be higher than that in a single surfactant system. Emulsion stability in mixed or anionic surfactant systems was found to be over 12 week, which was better than that in nonionic surfactant system. Emulsion particle size decreased as surfactant content increased. The Tg and molecular weight of emulsion polymer were inependent of the type, the amount and the mixing ratio of surfactant. Based on the results of stability and peel strength, the optimum nonionic surfactant ratio in total 4 g of surfactant mixture systems is found to be 40~60% by weight where the nonionic surfactant has 50 ethylene oxide groups and 16~18 carbon atoms in hydrophobic alkyl chain.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.170-176
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• 2003

The effect of xenobiotics on cytochrome P450 (CYP) and 7-ethoxyresorufin-O-deethylase (EROD) in hepatopancreatic microsome of surf clam, Coelomactra anti-quata, were investigated. The microsome isolated from the digestive gland of the surf clam, collected from the east coast of Korea, was in vitro exposed to p, p -DDT (0.1,0.4 and 1.0 mM) for 30 min and 2,3,7,8-TCDD (0.01, 0.04 and 0.1 ppb) and PCB-153 (0.01, 0.04 and 0.1 ppb) for 7 hr. In the case of DDT exposure, the CYP content and EROD activity of 1.0 mM exposure group increased up to about 117% and 120% of the DMSO solvent control group after 10 min. exposure, respectively. After 2 hr exposure of TCDD, the CYP content and EROD activity were also induced to the range of 103∼110% and 121∼139%, respectively. The PCB-153 exposure group showed 107∼115% of CYP content and 129∼140% of EROD activity after 2 hr exposure. Three test chemicals apparently induced CYP and EROD activity in the microsome of surf clam. The inducing potentials depend en the test chemicals.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.2
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• pp.144-152
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• 2005

To evaluate the effect of lead biomarkers including bone lead on neurobehavioral test in lead workers, 652 lead workers without any occupational exposure to organic solvent, mercury and arsenic were agreed to participate this study. For the control subjects 102 non-occupationally lead exposed blue collar workers in general manufacturing industries were also joined this study. All study subjects joined this study with written informed consent. The study variables of lead exposure were blood and patella lead. For the general characteristics of study subjects, standardized questionnaire regarding age, sex, past disease history, job duration, body mass index (BMI), drinking and smoking habit were provided. For the past history of neurotoxicity related diseases, all study subjects were interviewed by qualified occupational health physician. The results obtained were as follows: 1. Compared with controls without occupational lead exposure, lead exposed subjects had worse performance on all tests(p<0.05). 2. After adjustment for covariates (age, sex, job duration, education level, BMI, smoking and drinking status), the signs of the regression coefficients for blood lead were negative for 13 of the 14 tests. Blood lead was a significant predictor of poorer scores on 8 tests (simple reaction time(ms & root MSD), Trail-Making Test B, Digit Symbol Substitution, Purdue Pegboard assembly, Digit Span Test, Benton Visual Retention, and Purdue pegboard both hand). 3. After adjustment for covariates (age, sex, job duration, education level, BMI, smoking and drinking status), the signs of the regression coefficients for patella lead were negative for 12 of the 14 tests. Patella lead was a significant predictor of poorer scores on 8 tests (simple reaction time(ms). Purdue Pegboard assembly, Digit Span Test, Benton Visual Retention. Pursuit Aiming rest (no. of correct & no. of incorrect), Purdue pegboard non-dominant hand and both hand). With above results, blood lead and patella lead were associated with poorer performance of neurobehavioral tests. In addition, patella lead was confirmed to be better predictor of manual dexterity test in neurobehavioral test battery in lead workers

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.208-223
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• 1994

The purpose of this study was to evaluate the efficiency of diffusive(or passive) sampler in measuring airbone organic solvents. Diffusive samplers are generally simple in construction and do not require power for operation. The efficiency of the diffusive samplers has not sufficiently been investigated in Korea. Three types of samplers were studied in this study. The sampling and analytical results by passive samplers were compared with results by charcoal tube method recommended by NIOSH(National Institute for Occupational Safty and Health). The following characteristics are identified and studied as critical to the performance passive monitors; recovery, reverse diffusion, storage stability, accuracy and precision, face velocity and humidity, n-Hexane, TCE(trichloroethylene) and toluene were used as test vapors. A dynamic vapor exposure system consisting of organic vapor generator and sampling chamber for evaluating diffusive samplers are made. The results of the study are summarized as follows. 1. NIOSH recommands that the overall accuracy of a sampling method in the range of 0.5 to 2.0 times the occupational health standard should be ${\pm}25$ percent for 95 percent confidence level. Among three types of diffusive samplers, sampler A has permeation membrane and samplers Band C have diffusive areas, samplers A and B met the criterion that overall accuracy for 95% confidence level of the samplers were within ${\pm}25$ percent of the reference value. Sampler C had overall accuracy ${\pm}9.6%$ and ${\pm}11.8%$ in hexane and TCE, respectively. The concentration of toluene was overestimated in sampler C with overall accuracy of ${\pm}43.9%$. 2. The desorption efficiencies of diffusive samplers were 96-107%. 3. There was no significant sampe loss during four weeks of storage both with and without refrigeration. 4. There was no significant reverse diffusion, when the samplers were exposure to clean air for 2 hours after sampling for 2 hours at the level of 2 TLY. 5. In case of 8 hours sampling, relative differences(RD) of concentrations between charcoal tube method and diffusive method were 15-39%, 13-46%, and 4-35% for sampler A, B and C, respectively. The performance was poor in 8 hours sampling for multiple substance monitors. 6. At high velocity(100 cm/sec), samplers B and C overestimated the concentrations of organic vapors, and sampler A with permeation membrance gave better results. 7. At 80% relative humidity, samplers showed no siginificant effect. Low humidity also did not affect the diffusive samplers.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.370-376
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• 1998

The extraction yield of MeOH extract of green teas, oolong tea and black tea were 3 to 5, 4 to 5, and 5 to 7 fold higher than those of EtOH and EtAC extract, respectively. The amount of total catechins of EtAC extract of the black tea, and of the green teas and oolong tea were three- and two-fold higher than that of EtOH or MeOH extract of the corresponding teas, respectively. The antioxidative activities of EtOH, MeOH and EtAc extract were considerably higher than that of BHT and $dl-{\alpha}-tocopherol$ at 200 ppm level. The antioxidative activities of EtOH and MeOH extract at 200 and 500 ppm level, and of EtAc extract at 200 ppm level varied depending on the type of tea as follows : green tea I > green tea II > green tea III > oo-long tea> black tea. The antioxidative activity increased as the content of EGC increased. But the antioxidative activity of MeOH extract at 1000 ppm level, and of EtAc extract at 500 and 1000 ppm level were not affected by the content of EGC and EGCG.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6117-6121
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• 2015

Background: Most northeast Thai vegetables may play roles in human health by acting as antioxidant and anticancer agents. Recent study showed that Cratoxylum formosum subsp. pruniflorum (Kurz.) Gogel. (Teawdang) could inhibit growth of liver cancer cell lines. Cervical cancer, which has human papilloma virus as its main cause, is found at high incidence in Thailand. Due to increasing drug resistance, searches for potential anticancer compounds from natural source are required. Therefore, our purpose was to evaluate the cytotoxicity of Teawdang extracts in cervical cancer cell lines. Materials and Methods: Teawdang edible parts, purchased from Khon Kaen market during July-October 2013 was extracted with organic solvent. Phenolic profiles of crude hexane (CHE), ethyl acetate (CEE), methanol (CME) and water (CWE) extracts were performed by high performance liquid chromatographic (HPLC) techniques. Their cytotoxic effects on cervical cancer cells were investigated with HPV-non infected (C-33A) and HPV-infected (HeLa and SiHa) cell lines. Results: HPLC profiles showed that all crude extracts contained caffeine, ferulic acid and resveratrol. CME and CEE had high contents of gallic acid and quercetin. Catechin was found only in CWE. Cytotoxicity test showed that CEE had the lowest IC50 on HeLa ($143.18{\pm}13.35 {\mu}g/mL$) and SiHa cells ($106.45{\pm}15.73{\mu}g/mL$). C-33A cells were inhibited by CWE ($IC50=130.95{\pm}3.83{\mu}g/mL$). Conclusions: There were several phenolic compounds in Teawdang extracts which may have cytotoxic effects on cervical cancer cell lines. Investigation of these bioactive compounds as new sources of anticancer agents is recommended.