• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.261-269
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• 2012

In this study, 18 kinds of Korean medicinal herb extracts were examined for anti-microbial activities against pathogenic microorganisms. The methanol (MeOH) extracts from Schizandra chinensis, Rhus javanica and Caesalpinia sappan exhibited antimicrobial activities against most pathogenic microorganisms at concentrations of 5 mg/mL, whereas the other 15 extracts exhibited anti-microbial activities at concentrations of 30 mg/mL. The minimum concentration at which Schizandra chinensis extracts inhibited for S. epidermidis and Bor. bronchiseptica was 0.6 mg/mL. The MeOH extracts from Schizandra chinensis, Caesalpinia sappan, Rhus javanica and Seutellaria baicalensis which had higher anti-microbial activities were subsequently fractionated using 5 different solvents, and further screened for anti-microbial activities. The inhibitory effects of ethyl acetate (EtOAc) extracts on microbial growth were greater compared to any other solvent extracts. In order to investigate the inhibitory effect of Korean medicinal herbs with high anti-microbial activities on microbial proliferation, the MeOH extracts at concentrations of 0, 100, 300 and 500 ppm were added to the media. No addition of extracts caused rapid growth of microbes after 12 hours incubation. As the concentration of extracts from Rhus javanica and Caesalpinia sappan increased, the growth-inhibiting effect on gram-positive bacteria including S. aureus, S. epidermidis, and L. monocytogenes was prominent. Rhus javanica extracts exhibited growth-inhibiting activity for gram-negative bacteria including Sal. Pullorum and Sal. Choleraesuis. The low concentration of extracts from Rhus javanica and Caesalpinia sappan exhibited the growth of Bor. bronchiseptica and E. coli serotype $O_8$. However, the higher concentration of extracts from Rhus javanica and Caesalpinia sappan exhibited a strong inhibitory effect on microbial proliferation.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.461-467
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• 2018

In this study, $(n-BuCp)_2ZrCl_2$, was supported on $SiO_2/MgCl_2$ binary support. Before supporting the catalyst, the $SiO_2/MgCl_2$ binary support was surface treated with three different alkyl aluminum compound, namely trimethylaluminum, triethylaluminum, and ethylaluminum sesquichloride. The synthesized surface-treated $SiO_2/MgCl_2$ supported metallocene catalysts were used for the copolymerization of ethylene and 1-hexene. Their catalytic properties and performances were analyzed through BET, XPS analysis, ICP-AES analysis, and FE-SEM. While the resulting copolymers were analyzed through DSC analysis, GPC analysis, 13C-NMR analysis, and FE-SEM. The analysis of synthesized surface-treated $SiO_2/MgCl_2$ supported metallocene catalysts showed that the Zr content of these catalysts is relatively lower compared to that of the catalyst supported on $SiO_2$. This could be attributed to the reduction in the surface area of $SiO_2$ due to the presence of recrystallized $MgCl_2$ and alkyl aluminum. Furthermore, they exhibited a better copolymerization activity compared to that of $SiO_2$ supported catalyst, particularly the EASC-surface treated binary support, which has the highest activity of 1.9 kg PE/($mmol-Zr^*hr$) because EASC acts as a strong Lewis acid. It could also be observed that the larger the ligand of alkyl aluminum used, the rougher the particle surface of the resulting polymer.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.287-298
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• 2022

This study investigated the changes in the physiochemical property, phytochemical content, nutritional content and antioxidant activity of Polygoni multiflori Radix by steam, aging, and fermentation. After processing Polygoni multiflori Radix (PMR), pH slightly decreased, while acidity increased (pH 5.70→4.78, acidity 0.23→0.29%). The reducing sugar content increased after aging and fermentation from 1.19 mg/g (PMR) to 1.40 (fermented PMR, FPMR), 1.30 (red PMR, RPMR), 1.53 (fermented red PMR, FRPMR), 1.99 (black PMR, BPMR), and 2.33 mg/g (fermented black PMR, FBPMR). Total phenolic content was highest in PMR (6.05 mg/g) and total flavonoids and maillard product were increased after aging and fermentation of PMR, and were the highest in BPMR (1.60 mg/g) and FBPMR (2.76 O.D.), respectively. The major phytochemical was 2,3,5,4'-tetrahydroxystilbene-2-0-α-glucoside, which were highest in PMR (64.9 mg/g) with 46.47 mg/g at FPMR, 33.94 mg/g at RPMR, 48.76 mg/g at FRPMR, 36.68 mg/g at BPMR and 34.35 mg/g at FBPMR. The main fatty acids and free amino acids were detected as palmitic acid (C16:0) and proline, respectively. Generally, 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical scavenging activities and FRAP reducing powers were shown high in PMR (39.06%, 98.32%, and 2.61 O.D. in extracts concentration 1.0 mg/mL), then were decreased after aging and fermentation.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.87-94
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• 2017

In this study, a catalyst based on $Pt/Al_2O_3$ supported on Mg was prepared by a wet impregnation method to investigate the $CH_4-SCR$ reaction characteristics of various alumina supports. Alumina supported on $Pt/Al_2O_3$ catalyst was converted to an $Al_2O_3$ composite, and when Mg was added, oxygen species of the active metal Pt were controlled due to electrophobic characteristics. Oxygen-controlled Pt used as a reducing agent inhibited the oxidation of $CH_4$ to $CO_2$. The addition of Mg also promoted the adsorption of NO species and the conversion of NO to $NO_2$ due to the NOx storage property on the catalyst surface.

• Journal of Life Science
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• v.29 no.10
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• pp.1111-1119
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• 2019

Prunus mume, known as maesil in Korea, has been widely cultivated in East Asia and used as medication and food. However, because most of the previous studies concerning P. mume had been investigated its under extract state, detailed studies are still required for its extensive utilization. In this study, we evaluated the antioxidant and ${\alpha}-glucosidase$ inhibitory activities of solvent fractions of P. mume ethanol extracts. The ethyl acetate fraction showed higher DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power, and hydrogen peroxide scavenging activity than other fractions. The DPPH radical scavenging activities of ethyl acetate fraction was 67.79%; ABTS radical scavenging activity was 60.03%; reducing power ($OD_{670}$) was 1.26; and hydrogen peroxide scavenging activity was 93.18% at $500{\mu}g/ml$. Also, the ethyl acetate and methanol fraction showed effective levels of ${\alpha}-glucosidase$ inhibition activity (69.25% and 72.29% at $500{\mu}g/ml$). Total polyphenol contents and total flavonoid contents of the ethyl acetate fraction were 88.28 mg/g (gallic acid equivalent) and 70.38 mg/g (quercetin equivalent), respectively. These results suggest that the physiological activities of the ethyl acetate fraction are associated with its polyphenol and flavonoid contents. Therefore, this study can be used as basic data for developing natural antioxidants and potential functional material using P. mume.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.702-708
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• 1993

The study was attempted to elucidate the mechanism of GE-132(100mg/kg, p.o. for 6 weeks) on the metabolism of bromobenzene (460mg/kg, i.p. bid, for 2 days), which has potent carcinogenicity, mutagenicity and hepatotoxicity. It showed that activities of cytochrome p-450, aminopyrine demethylase and aniline hydroxylase, which have epoxide generating property, were not changed by GE-132 treatment. On the other hand, epoxide hydrolase was not changed but that glutathione S-transferase was significantly increased by GE-132 treatment. And also ${\gamma}-glutamylcysteine$ synthetase was not changed following the GE-132 treatment, but the activity of glutathione reductase was significantly increased. The level of hepatic glutathione which was decreased by bromobenzene recovered markedly by GE-132 pretreatment. It is concluded that the mechanism for the observed effect of GE-132 on bromobenzene metabolism is due to the induction of glutathione S-transferase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.973-979
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• 2016

Lentils (Lens culinaris) have been gaining increasing attention recently as a top five superfood, as they are high in protein and other essential nutrients, including folate, iron, potassium, and various antioxidants. In the present study, phenolic extracts from four different lentil cultivars (green, red, French, and beluga) were evaluated for their total phenolic contents and in vitro antioxidant activities. Total polyphenol and flavonoid contents of four different lentil extracts were 27.30~30.30 mg tannic acid equivalents (TAE)/g and 13.14~16.29 mg quercetin equivalents (QUE)/g, respectively. Beluga and red lentil extracts showed higher polyphenol contents than others (P<0.05), whereas there was no significant difference in flavonoid contents among the four lentil cultivars. $RC_{50}$ values of the lentil extracts for DPPH radical, ABTS radical, and $H_2O_2$ were $57.42{\sim}64.49{\mu}g/mL$, $66.11{\sim}75.69{\mu}g/mL$, and $59.72{\sim}72.86{\mu}g/mL$, respectively. Among the four lentil extracts, beluga lentil extract showed the most potent scavenging effect in all three reactive oxygen species (ROS) scavenging assays, and thus beluga extract was further tested for its inhibitory effect on early peroxidation of linoleic acid. The results showed that beluga lentil extract significantly inhibited linoleic acid peroxidation in a dose-dependent manner (concentration required for 50% reduction=$222.76{\m}g/mL$). In addition, beluga lentil extract showed a significant protective effect against alcohol-induced cytotoxicity in AML-12 cells (normal mouse hepatocyte cell line). Taken together, these results suggest that lentil extracts represent potential sources of natural antioxidants, and further studies will be necessary to determine their protective effects against oxidative stress in vivo.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.832-838
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• 2009

The inhibitory effects of solvent extracts from dried beet (Beta vulgaris) on $H_2O_2$-induced oxidative stress in cell systems and on the growth of cancer cell lines (HT-29 human colon cancer and AGS human gastric adenocarcinoma cells) were investigated. Inhibitory effects of acetone with methylene chloride (A+M) and methanol (MeOH) extracts on the growth of HT-29 and AGS cancer cells increased in a dose dependent manner (p<0.05). The inhibitory effect was more significant on the growth of AGS cells and A+M extracts had a higher inhibitory effect compared to MeOH extracts. The treatments of hexane, 85% aq. methanol, butanol and water fractions significantly inhibited the growth of both cancer cells (p<0.05). Among fractions, hexane and 85% aq. methanol fractions showed higher inhibitory effects. In order to determine the protective effect on $H_2O_2$-induced oxidative stress, DCHF-DA (dichlorodihydrofluorescin diacetate) assay was conducted. The A+M and MeOH extracts of dried beet appeared to significantly reduce the levels of intracellular (ROS) with dose responses. Among the fractions, 85% methanol fractions showed a higher protective effect on production of lipid peroxides. These results indicate that the intake of dried beet may improve oxidative stress in cell and reduce cancer risk.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.157-164
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• 2000

The major components were isolated from the n-hexane, EtOAc and BuOH extract of Galla Rhois(Rhus Javanica Linne). Their structures were characterized as syringic acid, gallic acid methylester, protocatechuic acid, gallic acid and 1, 2, 3, 4, $6-penta-O-galloyl-{\beta}-D-glucose$. This study was carried out to investigate the biological activities of isolated compounds. Five compounds were tested for hepatoprotective effects on CCl4-induced cytotoxicity in primary cultured rat hepatocytes and antioxidative effect on Ferric-Thiocyanate method and TBA method. As a result, isolated five compounds showed stronger antioxidative activity than tocopherol, and the antioxidative activity of gallic acid methylester, protocatechuic acid and syringic acid were similar to that of BHA on Ferric-Thiocyanate method. Specially 1, 2, 3, 4, $6-penta-O-galloyl-{\beta}-D-glucose$ showed stronger effect of lipid-peroxidation inhibition than BHA. Gallic acid appeared stronger inhibitory effect of malondialdehyde on TBA method. Hepatoprotective effect of 1, 2, 3, 4, $6-penta-O-galloyl -{\beta}-D-glucose$ was similar or even higher than that of glycyrrhizin on primary cultured rat hepatocyte cytotoxicity.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.1-7
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• 2003

The aim of this work was to investigate the characterization and sequence of catechol 2,3-dioxygenase isolated from Delfia sp. JK-2, which could utilize aniline as sole carbon, nitrogen and energy source. In initial experiments, several characteristics of C2,3O separated with ammonium sulfate precipitation, DEAE-sepharose were investigated. Specific activity of C2,3O was approximately 4.72 unit/mg. C2,3O demonstrated its enzyme activity to other substrates, catechol and 4-methylcatechol. The optimum temperature of C2,3O was $$Cu^{2+}$^{\circ}C$, and the optimal pH was approximately 8. Metal ions such as $Ag^{+}$, $Hg^{+}$, and $Cu^{2+}$ showed inhibitory effect on the activity of C2,3O. Molecular weight of the enzyme was determined to approximately 35 kDa by SDS-PAGE. N-terminal amino acid sequence of C2,3O was analyzed as $^{1}MGVMRIG-HASLKVMDMDA- AVRHYENV^{26}$, and exhibited high sequence homology with that of C2,30 from Pseudomonas sp. AW-2, Comamonas sp. JS765, Comamonas testosteroni and Burkholderia sp. RPO07. PCR product was amplified with the primers derived from N-terminal amino acid sequence. In this work, we found that the amino acid sequence of Delftia sp. JK-2 showed high sequence homology of C2,3O from Pseudomonas sp. AW-2 (100%) and Comamonas sp. JS765 (97%).