• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.145-145
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• 2003

A method for the determination of alkylphenols, chlorophenols and bisphenol A in paper materials using GC/MS-SIM has been developed. Eleven endocrine disrupting chemicals (EDCs) of phenols in paper samples were extracted with acetonitrile. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 82.4∼108.8 % by area ratio of pheranthrene-d$\sub$10/ vs bisphenol A d$\sub$l6/. (isoBOC derivatization and TBDMS derivatization) The SIM responses were linear with the correlation coefficient varying 0.9717∼0.9995 (isoBOC derivatization), and 0.9842∼0.9980 (TBDMS derivatization). The range of concentrations was respectively, 0.95∼l.44 ng/g in 2,4-dichlorophenol, 1.01∼1.17 ng/g in t-butylphenol, 2.17∼5.84 ng/g in pentachlorophenol, 12.68∼14.88 ng/g in nonylphenol and 30.84∼153.72 ng/g in bisphenol A.

• Analytical Science and Technology
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• v.30 no.1
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• pp.20-25
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• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Toxicological Research
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• v.27 no.4
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• pp.253-259
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• 2011

Transforming growth factor ${\beta}$ (TGF-${\beta}$) is involved in cellular processes including growth, differentiation, apoptosis, migration, and homeostasis. Generally, TGF-${\beta}$ is the inhibitor of cell cycle progression and plays a role in enhancing the antagonistic effects of many growth factors. Unlike the antiproliferative effect of TGF-${\beta}$, E2, an endogeneous estrogen, is stimulating cell proliferation in the estrogen-dependent organs, which are mediated via the estrogen receptors, $ER{\alpha}$ and $ER{\beta}$, and may be considered as a critical risk factor in tumorigenesis of hormone-responsive cancers. Previous researches reported the cross-talk between estrogen/$ER{\alpha}$ and TGF-${\beta}$ pathway. Especially, based on the E2-mediated inhibition of TGF-${\beta}$ signaling, we examined the inhibition effect of 4-tert-octylphenol (OP) and 4-nonylphenol (NP), which are well known xenoestrogens in endocrine disrupting chemicals (EDCs), on TGF-${\beta}$ signaling via semi-quantitative reverse-transcription PCR. The treatment of E2, OP, or NP resulted in the downregulation of TGF-${\beta}$ receptor2 (TGF-${\beta}$ R2) in TGF-${\beta}$ signaling pathway. However, the expression level of TGF-${\beta}1$ and TGF-${\beta}$ receptor1 (TGF-${\beta}$ R1) genes was not altered. On the other hand, E2, OP, or NP upregulated the expression of a cell-cycle regulating gene, c-myc, which is a oncogene and a downstream target gene of TGF-${\beta}$ signaling pathway. As a result of downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc, E2, OP, or NP increased cell proliferation of BG-1 ovarian cancer cells. Taken together, these results suggest that E2 and these two EDCs may mediate cancer cell proliferation by inhibiting TGF-${\beta}$ signaling via the downregulation of TGF-${\beta}$ R2 and the upregulation of c-myc oncogene. In addition, it can be inferred that these EDCs have the possibility of tumorigenesis in estrogen-responsive organs by certainly representing estrogenic effect in inhibiting TGF-${\beta}$ signaling.

• Journal of fish pathology
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• v.21 no.1
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• pp.57-66
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• 2008

Striped bitterling, Acheilognathus yamatsutae (TL: 4.25 ㎝, TW: 0.73 g)were exposed to 0.3, 1.3, 17.6 and 33.7 ㎍ L-1 (nominal concentrations) of nonylphenol (NP) for a period of 20 weeks. We studied on accumulation, growth and survival rate. After 20 weeks of exposure, the accumulation of NP in the body of the female and male was increased with increasing dose-dependent and female was higher than male. 4 weeks of exposure, TL of female striped bitterling was found to be increased in all of the dose group compared to control and 12 weeks of exposure, similar or some decreased in all of the dose group compared to control. 20 weeks of exposure, increased in all of the dose group compared to control and TL at 33.7 ㎍ NP L-1 were significantly higher than those in control (p <0.05). 4 weeks of exposure, TL and TW of male striped bitterling was found to be increased in all of the dose group compared to control and significantly higher in TL of 33.7 ㎍ NP L-1 (p <0.05). 12 and 20 weeks of exposure, TL and TW decreased in all of the dose group compared to control and significantly lower in 1.3 ㎍ NP L-1 of 12 weeks. Survival rate in both groups decreased with increasing NP concentration and there was a significant difference between control group and experimental groups exposed to each NP concentration.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.14-22
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• 2009

In vitro cytotoxicity of 23 alkyl phenols (APs) on human cervical cancer cell lines (HeLa) was determined using the lactate dehydrogenase (LDH) cytotoxicity assay. Two different sets of descriptors were used to construct the calibration model based on Genetic Algorithm-Multiple Linear Regression (GA-MLR) based on the experimental data. A statistically robust Structure-Activity Relationships (QSAR) model was achieved ($R^2$=95.05%, $Q^2_{LOO}$=91.23%, F=72.02 and SE= 0.046) using three Dragon descriptors based on Me (0D-Constitutional descriptor), BELp8 (2D-Burden eigenvalue descriptor) and HATS8p (3D-GETAWAY descriptor). However, external validation could not fully prove its validity of the selected QSAR in characterization of the cytotoxicity of APs towards HeLa cells. Nevertheless, the cytotoxicity profiles showed a finding that 4-n-octylphenol (4-NOP), 4-tert-octyl-phenol (4-TOP), 4-n-nonylphenol (4-NNP) had a more potent cytotoxic effect than other APs tested, inferring that increased length and molecular bulkiness of the substituent had important influence on the LDH cytotoxicity.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.45-55
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• 2003

The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrom-etry-selected ion monitoring (GC/MS-SIM) mode followed by two work-up methods for comparison; isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in paper samples were extracted with acetonitrile. Also, solid -phase extraction (SPE) with XAD -4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The SIM responses were linear with the correlation coefficient varying 0.9717 ∼ 0.9995 (isoBOC derivatization), and 0.9842 ∼ 0.9980 (TBDMS derivatization). The recoveries were 82.4 ∼ 108.8％) by area ratio of phenanthrene -d$\_$10/ vs bisphenol A-d$\^$l6/. (isoBOC derivatization and TBDMS derivatization) The range of concentrations was respectively, 0.95 ∼ 1.44 ng/g in 2,4-dichlorophenol, 1.01 ∼ 1.17 ng/g in t-butylphenol,2.17 ∼ 5.84 ng/g in pentachlorophenol, 12.68 ∼ 14.88 ng/g in nonylphenol and 30.84 ∼ 153.72 ng/g in bisphenol A.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.351-356
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• 2008

Titania nanoparticles were prepared by controlled hydrolysis of titanium tetraisopropoxide (TTIP) in water-in-oil (W/O) and microemulsion stabilized with a nonionic surfactant, N P-10 (Polyoxyethylene Nonylphenol Ether: $C_9H_{19}C_6H_4(OCH_2CH_2)_{10}OH$)). The nanosized particles prepared in W/O microemulsion were characterized by FT-IR, TEM, XRD, TGA, and DTA. In addition, the photocatalytic degradation of p-nitrophenol has been studied by using a batch reactor in the presence of UV light in order to compare the photocatalytic activity of prepared nanosized titania. The nanaosized titania particles calcined at $300{\sim}600^{\circ}C$ showed an anatase structure, but it transformed to a rutile phase above $700^{\circ}C$ of calacination temperature. With an increase of $W_o$ ratio, the crystallite size increased but photocalytic activity decreased. The titania synthesized at $W_o=5$, R = 2, and calcined at $400{\sim}500^{\circ}C$ showed the highest activity on the photocatalytic degradation of p-nitrophenol.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.401-408
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• 2001

The ethanol extract and n-hexane fraction of Commiphora molmol Engl. showed minimum inhibitory concentration of 50 ppm and 25 ppm, respectively, on 5 strains of Listeria monocytogenes at $32^{\circ}C$. The purified substance, C3-3-2 fraction, was isolated by silica gel column and preparative thin layer chromatography from n-hexane fraction of Commiphora molmol Engl. The C3-3-2 fraction showed a strong bactericidal activity on 5 strains of L. monocytogenes at the concentration of 10 ppm in tryptic soy broth medium. At that concentration, the viable count was reduced $5{\sim}6$ log cycle from initial cell number. The n-hexane fraction of Commiphora molmol Engl. showed strong growth inhibition at the concentration of 25 ppm on Bacillus cereus and Staphylococcus aureus, at 50 ppm in broth on Salmonella enteritidis, and at 500 ppm on Vibrio parahaemolyticus. The purified antimicrobial substance, the C3-3-2 fraction, was identified as m-nonylphenol by on the basis of the $^1H-,\;^{13}C-NMR$ and EI/MS data. For the application test, the C3-3-2 fraction which was purely isolated from Commiphora molmol Engl. at 100 ppm were applied to minced Alaska pollack and ground beef at $32^{\circ}C$ and $5^{\circ}C$. The antimicrobial substances did not reduce L. monocytogenes ATCC 19113 at $32^{\circ}C$, while they reduced L. monocytogenes ATCC 19113 in viable number at $5^{\circ}C$. However, the antimicrobial effect of C3-3-2 fraction in food system was lower than that of broth condition.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.123-126
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• 2002

Pollutants that are persistent, bioaccurnulative, and toxic have been linked to numerous adverse effects in human and animals, PBTs include heavy metals, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic compounds (PACs) in addition to pesticides. This study focuses on toxic effects of the PBTs except pesticides on insects. Eight PBTs were selected from subgroups: three heavy metals (Pb, Hg, and Cd), two PCB mixtures (Aroclor mixtures 1 and 2), 2,3,7,8-tetrachlorodibenzo-p-dioxin, two monophenols (4-octylphenol and 4-nonylphenol), and tetrabutyltin, Beet armyworm, Spodoptera exigua, was used as test target insect species. Three physiological markers (metamorphosis, immune reaction, and follicle patency) were assessed in each exposure to different doses of the PCBs. Heat-shock proteins as molecular markers were also analyzed in response to the PCBs. All tested PBTs were toxic to metamorphosis from larvae to pupae when they were applied with diet. Two PCB mixtures were the most toxic compounds in this assay by giving significant toxicity at 0.005 ppm, while others had from 10 to 1000 ppm. Dioxin (0.1 ppb), tetrabutyltin (0.1 ppb), Pb (10 ppb), and Hg (0,01 ppb) were potent to inhibit immune reactions analyzed by inducing phenoloxidase activity and blocked phospholipase $A_2$ enzyme, Tetrabutyltin and dioxin significantly induced follicle cell patency, but their effects were lower than that of endogenous juvenile hormone, Dioxin, Pb, Hg, and Cd could induce the expression of heat shock proteins that were detected by immunoblotting against human HSP70 monoclonal antibody. HSP78 and HSP80 were upregulated in response to the PBTs. This expression was detected from the fat body and epidermis at as fast as 4h after injection. All these results clearly suggest that PBTs give significant ecotoxicity to insects that are valuable organisms in our environment.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.112-112
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• 2001

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that activates the aryl hydrocarbon receptor (AhR) and disrupts multiple endocrine signaling pathways by enhancing ligand metabolism, altering hormone synthesis, down regulating receptor levels, and interfering with gene transcription. And TCDD-mediated gene transactivation via the AhR has been shown to be dependent upon estrogen receptor (ER) expression in human breast cancer cells. In the present study, we have examined the effect of natural estrogen, phytoestrognes and environmental estrogens on the regulation of CYP1A1 gene expression in MCF-7 human breast cancer cell line. that ER and AhR are co-expressed. pCYP1A1 -luc reporter gene was transiently transfected into MCF-7 cells. These cells were treated with various chemicals and then luciferase assay was carried out. 17be1a-estradiol significantly inhibited TCDD stimulated luciferase activity dose dependently and this inhibition was partially recovered by concomitant treatment of tamoxifen. 17beta-estradiol metabolites, 2-hydroxyestradiol and 16alpha-estriol resulted in less potent inhibitory effect than estradiol and synthetic estrogen, diethylstilbestrol (DES) showed no effect on CYP1A1 gene expression. This study demonstrated that estrogen down-regulated TCDD stimulated CYP1A1 expression via ER mediation. And we have found out that several flavonoids such as genistein, kaempferol, daidzein, naringenin, and alkylphenols such as nonylphenol, 4-octylphenol and resveratrol also inhibited TCDD induced CYP1A1 expression like estrogen.