• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.8-14
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• 2002

Cotinine, one of nicotine metabolites, has been blown to reduce 4-(methylnitro samino)-1-(3-pyridyl)-1-butanone(NNK)- induced $O^{6}$MeG DNA adducts significantly in A/J mice when administered together with NNK. In order to examine the effects of phyto-extract mixture on the conversion of cotinine from nicotine, cellular and clinical experiments were carried out. When the phyto-extract mixture was added to culture media, human liver cells (FLCFR5) produced cotinine from nicotine 2~3 times compared to the control. The phyto-extract mixture which was microinjected into Xenopus oocyte along with nicotine showed the almost similar production of cotinine compared with the results of hepatic cell culture. In clinical test employing 17 to 20 healthy men, concentrations of urinary cotinine derived from smoking after taking photo-extract mixture increased up to 2 times compared to the control group. These results indicatethat the phyto-extract mixture can increase the metabolic efficiency of nicotine to cotinine, leading to the reduced formation of $O^{6}$MeG DNA adducts.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.764-770
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• 2014

This study assessed analysis of N-nitrosamines by separation, identification, and quantification using a gas chromatography (GC) mass spectrometer (MS) with electron impact (EI) mode. Samples were pretreated by a automated solid phase extraction (SPE) and a nitrogen concentration technique to detect low concentration ranges. The analysis results by EI-GC/MS (SIM) and EI-GC/MS/MS (MRM) on standard samples with no pretreatment exhibited similar results. On the other hand, the analysis of pretreated samples at low concentrations (i.e. ng/L levels) were not reliable with a EI-GC/MS due to the interferences from impurity peaks. The method detection limits of eight (8) N-nitrosamines by EI-GC/MS/MS analysis ranged from 0.76 to 2.09 ng/L, and the limits of quantification ranged from 2.41 to 6.65 ng/L. The precision and accuracy of the method were evaluated using spiked samples at concentrations of 10, 20 and 100 ng/L. The precision were 1.2~13.6%, and the accuracy were 80.4~121.8%. The $R^2$ of the calibration curves were greater than 0.999. The recovery rates for various environmental samples were evaluated with a surrogate material (NDPA-$d_{14}$) and ranged 86.2~122.3%. Thus, this method can be used to determine low (ng/L) levels of N-nitrosamines in water samples.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.748-752
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• 1990

This paper was investigated to elucidate the nitrite-scavenging ability of roasted-barley extracts. Roasted-barley extracts exhibited nitrite-scavenging ability. The nitrite-scavenging ability of roasted-barley extracts showed pH-dependent, and did the highest at pH 1.2 and the lowest at pH 6.0. The roasting temperature and time of barley examined influenced the nitrite-scavenging ability of roasted-barley extracts. The water soluble fraction obtained from barley roasted at $230^{\circ}C$ for 90 min showed higher the nitrite-scavenging effect than the others. Ethanol soluble fraction which is further fractionated from water soluble fraction was most effective in nitrite-scavenging.

• Food Science and Preservation
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• v.13 no.6
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• pp.762-768
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• 2006

To assess utilization of onions extract as natural food additives, ethyl acetate, ethanol and hot water extract of freeze dried onions (red, white and yellow) were exmined for their chemical component and nitrite scavenging activity. Contents of total organic acid and total free sugar were in the range of $135.4{\sim}1,2557mg%$ and $51.7{\sim}62.9%$ as dry matter bases, respectively, and then their content of three onions were higher in ethylacetate and hor water extracts than in ethanol extract. Contents of total phenol and total flavonoids were in the range of $9.3{\sim}$13.3 % and $159.8{\sim}584.1mg%$ as dry matter bases, respectively, and their content of red onion extract by three solvent were higher than those of other onion extract. Nitrite-scavenging activities (NSA) of onion extracts were increased by lowering pH and elevating onion concentrations, and their values of ethanol and hot water were about 55% in addition of 10 mg/mL of red onion extract showing that NSA of red onion was twice higher than that of the other onions. In conclusion, the result indicated that red onion extract was very effective to inhibit nitrosamine formation at low pH condition as natural nitrite scavenging agent.

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.85-94
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• 1973

The stability constants of the charge-transfer complexes formed between three derivatives of nitrobenzene, i.e., 1,3,5-trinitrobenzene, m-dinitrobenzene, nitrobenzene and eleven organic molecules such as $\alpha-picoline$, pyridine, dimethylsulfoxide, N, N'-dimethylacetamide, tetrahydrofurane, 1, 4-dioxane, diethyl ether, acetonitrile, propylene oxide, epichlorohydrine, and methyl acetate, have been determined by ultraviolet absorption spectroscopy in carbon tetrachloride solution at 25.0$^{\circ}C$. The parameters of the electrostatic effect ($E_D$) and covalent effect ($C_D$) for the eleven organic compounds have been calculated from the modified equation of the double-scale enthalpy,$logK = E_AC_A+E_DC_D$ and also the shift of C=O vibrational frequency in infrared spectra for N,N'-dimethylacetamide have been measured from the solutions of above organic compounds. The empirical equation, ${\Delta}{\nu}_{C=O} = 37.4-5.47E_D+12.1C_D$, related to the parameters and the frequency shift has been derived. It seems that the stabilities of the complexes principally depend on the covalent effect. Especially it is found that $\pi$ orbitals in molecules, in addition to the parameters, play the important role in forming the charge-transfer complexes.

• Journal of the Korean Chemical Society
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• v.25 no.6
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• pp.376-382
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• 1981

The rates and the activation parameters for the reaction of phenacyl bromide with substituted anilines in methanol and dimethylformamide were measured. The effects of substituted anilines were discussed. The rate of the reaction was increased with the electron donating power of substituent and showed larger value in DMF than in MeOH. The isokinetic relationship was shown between ${\delta}H^{\neq}$ and ${\delta}S^{\neq}$, isokinetic temperature was 539 and $400^{\circ}C$ in MeOH and DMF respectively, but p-nitro aniline was deviated from linearity in both solvents caused by solvent effects. The excellent linear relationship between log k and p$K_a$ of substituted anilines was observed by following equation. log k = 0.57p$K_a$-1.28 (r = 0.996) in MeOH at $45^{\circ}C$, log k = 0.65p$K_a$-0.88 (r = 0.970) in DMF at $45^{\circ}C$. From the Hammett plot, this reaction was a nucleophilic displacement of aniline to phenacyl bromide and the following equation was obtained at $45^{\circ}C$. log k/$k_0$ = -2.00${\sigma}$ + 0.06 (r = 0.985) in MeOH; log k/$k_0$ = -2.22${\sigma}$ + 0.08 (r = 0.995) in DMF. Large deviation of p-nitro aniline in DMF is resulted from solvent effects too. From above results, the substituent effect of this reaction can be described as $S_N2$ mechanism and bond formation more proceeds in DMF relative to MeOH.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.656-663
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• 2001

The most representative nitrosamine derived from nicotine, nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), has been reported to cause lung cancer in A/J mice. It has been also demonstrated that NNK-induced lung tumorigenesis involves $O^6-methylguanine(O^6MeG)$ formation, leading to $GC\;{\rightarrow}\;AT$ transitional mispairing during DNA replication. Our in vitro experiment, modified from the method of DBA assay, examined the ability of phyto-extract mixture to inhibit the metabolism of nicotine to nitrosamines. The production of nitromorpholine from morpholine was inhibited about 75% at the concentration of 20 mg/mL of phyto-extract mixture, which was lower than vitamine C and green tea powder. NNK, which is a pro-carcinogen in laboratory animals, is hydroxylated primarily in liver and lung by CYP 1A2, 2A6 and 3A4. A critical phase. of NNK activation is its change to an unstable metabolite methyl-diazohydroxide via CYP-mediated ${\alpha}-hydroxylation$; and then it provides a methyl group to the DNA to form DNA adducts which can easily induce mutations. $Aroclor^R$ 1254 was used to induce CYPs in the liver of a Sprague-Dawley rat. The ability of various test samples to inhibit CYPs that participate in NNK activation was evaluated, following the removal of the liver from the rat. Microsomal CYPlA2 catalyzing the conversion of NNK into strong carcinogenic chemicals was inhibited more efficiently by phyto-extract mixture than green tea powder. These results indicate that phyto-extract mixture can be used to reduce $O^6MeG$ DNA adducts for chemoprevention.

• Journal of the Korean Chemical Society
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• v.39 no.12
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• pp.918-924
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• 1995

THMs and PCBs were separated and analysed with elution on Novapak ODS or $\mu-Bondapak$ phenyl column by an eluent containing p-nitrophenol (p-NP). THMs studied were CHCl3, CHBrCl2, CHBr2Cl, and CHBr3, and PCBs used were Aroclor 1221, 1242, 1248, $\alpha-$ and $\beta-BHC.$ It was thought that the retention on the stationary phase and sensitivities of the samples are related to the interaction between the sample and stationary phase or p-NP. THMs were separated completely on the ODS column by elution with MeOH-water (30 : 70) containing $1.0{\times}10^{-4}$ M p-NP and some of PCBs were separated on the phenyl column by elution with $CH_3CN$-water(50 : 50) containing $1.0{\times}10^{-4}$ M p-NP. Detection limits of THMs were from $1.0{\times}10^{-4}$ g to $1.0{\times}10^{-6}$ g. Aroclors were $2{\times}10^{-6}$ g, and $\alpha-$ and $\beta-BHC$ were $2{\times}10^{-4}$ g and $1.0{\times}10^{-4}$ g respectively.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.815-823
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• 2014

Green tea has been known to show beneficial effects on alleviating stress. The present study was conducted to determine the effects of dietary green tea on quality of eggs, during storage, laid by laying hens treated with corticosterone in order to mimic the current practice of the egg market. Hens were fed for 2 weeks one of three diets containing green tea at 0.0, 0.4 or 1.0%. Each dietary group was divided into two subgroups receiving corticosterone at 0 or 30 mg/kg for 1 week. Eggs, laid at 5-7 days following the initiation of corticosterone treatment, were stored at $10^{\circ}C$ for 1 or 5 weeks and then analyzed for egg quality. After 1 week of storage, egg weight was significantly increased by green tea (p<0.025) but decreased by corticosterone (p<0.0001), but no interaction was observed between both. Corticosterone decreased shell color (p<0.0001) but green tea significantly decreased shell strength (p<0.006). Yolk color, albumen height and Haugh unit were not affected by both treatments. After 5 weeks of storage, corticosterone resulted in reduced egg weight (p<0.01) and eggshell color (p<0.001) and increased shell strength, which were not attenuated by green tea. Taken together, the results of the current study show that dietary corticosterone reduces egg quality during storage, which are attenuated in part by dietary green tea.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.399-405
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• 2021

A number of studies have been conducted to prevent obesity due to the worldwide increasing rate of obesity and its adverse effects on our health. Recently, a relationship between obesity and gut microbiome has been reported. Fecal and cecal microbiota are generally targeted for examining the gut microbiome during dietary interventions. There is, however, no common understanding on which microbiota and how results elucidated from the data would differ. In this study, we conducted dietary induced obesity study and compared fecal and cecal microbiota affected by dietary interventions. Normal Diet and high fat diet were fed to 6 weeks old mice for 12 weeks, and 16 S rRNA genes amplified from fecal and cecal DNA were sequenced using MiSeq. Our results show that the 𝛼-diversity showed significant differences between the dietary interventions as well as cecal and fecal microbiota. The difference in the taxonomic compositions between cecal and fecal microbiota had become clearer at the family and genus level. At the genus level, Faecalibaculum and Lactobacillus were more abundant in the cecal and fecal microbiota, respectively. In general dietary intervention studies, dietary effects are more significant than type difference. However, the microbiota analysis results should be interpreted carefully, considering both diet and samples (feces/caecum).