• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.823-828
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• 2006

We established the optimal conditions for the hot water extraction of Camellia japonica compounds based on the yield, the stability (observed by peak changes on an HPLC chromatogram), and the 1,1-diphenyl-1-picrylhydrazyl radical-scavenging activity of the extracts. The extracts were prepared at $90^{\circ}C$ using six solution volumes (ranging from 100 mL to 600 mL), and four different extraction times (10, 30, 60, and 120 min). The results showed that increasing of the extraction volume elevated the radical-scavenging activity of the extracts; however, changes in volume had minimal affects on their yields and their stabilities. An increase in extraction time improved the compound yield; however, it reduced their stability and increased the deterioration of their radical-scavenging activity. Based on our results, we propose the following conditions to be optimal for the hot water extraction of dried C. japonica leaves: a water volume (mL) that is 60 times the weight (g) of the sample at a temperature of $90^{\circ}C$ for 30 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.85-88
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• 2015

This study attempted to establish an HPLC analysis method for determination of marker compounds as a part of material standardization for the development of health functional food materials from Perilla frutescens Britton var. acuta Kudo. The quantitative determination method of rosmarinic acid as a marker compound of P. frutescens Britton var. acuta Kudo extract (PFE) was optimized by HPLC analysis using a C18 column ($4.6{\times}150mm$, $5{\mu}m$) with 0.1% acetic acid as the elution gradient and methanol as the mobile phase at a flow rate of 1 mL/min and detection wavelength of 280 nm. The HPLC/UV method was applied successfully to quantification of the marker compound in PFE after validation of the method with linearity, accuracy, and precision. The method showed high linearity in the calibration curve at a coefficient of correlation ($R^2$) of 0.9995, and the limit of detection and limit of quantitation were $0.36{\mu}g/mL$ and $1.2{\mu}g/mL$, respectively. Relative standard deviation (RSD) values of data from intra- and inter-day precision were less than 3.21% and 1.43%, respectively. Recovery rate test at rosmarinic acid concentrations of 12.5, 25 and $50{\mu}g/mL$ scored between 97.04~98.98% with RSD values from 0.25~1.97%. These results indicate that the established HPLC method is very useful for the determination of marker compound in PFE to develop a health functional material.

• Nutritional Sciences
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• v.4 no.2
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• pp.85-90
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• 2001

The purpose of this study was to evaluate the antioxidative potential of Korean wild leaf vegetables in vivo as well as in vitro. The antloxidative activities of Pleurospemum kamtschaticum, Aderophora remotiflor and Aster gfheni were evaluated as a reference for Spinacia oleracea. Fifty rats were find either a control diet or one of several vegetable diets for 4 weeks. The level of thiobarbituric acid reactive substance (TBARS) and the activity of catalase and superoxide dismutase (SOD) in the liver were compared. The levels of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and triglyceride (TG) in plasma were also compared. Also, the contents of $\beta$-carotene, vitamin C, vitamin E and total phenolic compound, including flavonoid and thiobarbituric acid (TBA) value using linoleic acid model system, were measured in Korean wind leaf vegetables. The TBARS values of Aderophora remotiflor and Aster giheni tended to be lower than that of Spinacia olerncea. The SOD activity of Artrr glheffi was significantly higher than that of Spinacia oleracea and reached 265% that of the control animals, whereas there was no difference between the control animals and the vegetable diet animals in terms of catalase activity. Compared to the control animals, TG and TC levels were significantly solver and showed a lower artheriosclerotic index. TBA values of Pleurospemum Kamschaticum and Aderophora remptiflor were only 18% of control value. TBA value of Spinacia olerucra was 41% of control value. These results suggest that Aderophora remotinor and Aster glheni could have antioxidative potency in vivo as well as in vitro and potential value far functional flood to improve the plasma lipid profile. flavonoid and phenolic compounds could be the major contributing factor in the antioxidative potential of Aderophora remotiflor and Aster glheni.

• Molecules and Cells
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• v.20 no.1
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• pp.1-16
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• 2005

The peptidyl transferase center (PTC) is located in a protein free environment, thus confirming that the ribosome is a ribozyme. This arched void has dimensions suitable for accommodating the 3'ends of the A-and the P-site tRNAs, and is situated within a universal sizable symmetry-related region that connects all ribosomal functional centers involved in amino-acid polymerization. The linkage between the elaborate PTC architecture and the A-site tRNA position revealed that the A-to P-site passage of the tRNA 3'end is performed by a rotatory motion, which leads to stereochemistry suitable for peptide bond formation and for substrate mediated catalysis, thus suggesting that the PTC evolved by genefusion. Adjacent to the PTC is the entrance of the protein exit tunnel, shown to play active roles in sequence-specific gating of nascent chains and in responding to cellular signals. This tunnel also provides a site that may be exploited for local co-translational folding and seems to assist in nascent chain trafficking into the hydrophobic space formed by the first bacterial chaperone, the trigger factor. Many antibiotics target ribosomes. Although the ribosome is highly conserved, subtle sequence and/or conformational variations enable drug selectivity, thus facilitating clinical usage. Comparisons of high-resolution structures of complexes of antibiotics bound to ribosomes from eubacteria resembling pathogens, to an archaeon that shares properties with eukaryotes and to its mutant that allows antibiotics binding, demonstrated the unambiguous difference between mere binding and therapeutical effectiveness. The observed variability in antibiotics inhibitory modes, accompanied by the elucidation of the structural basis to antibiotics mechanism justifies expectations for structural based improved properties of existing compounds as well as for the development of novel drugs.

• Journal of Nutrition and Health
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• v.44 no.6
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• pp.488-497
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• 2011

Oxygen is necessary to sustain life, yet cellular oxygen metabolism creates destructive elements called free radicals. Free radicals are chemically unbalanced and carrying free electrons that can damage molecules, potentially damaging the cell itself. For this reason, many antioxidant products, including supplements and functional foods, are being developed. In particular, natural products are rich sources of pharmacologically active compounds. The purpose of this study was to investigate the antioxidant effects of target biomaterials in Korean traditional spices such as diallyl sulfide (DAS), capsaicin (CAP), and gingerol (GGR), and to investigate the response of the antioxidant defense system to oxidative stress by hydrogen peroxide ($H_2O_2$) compared to sulforaphane (SFN) in HepG2 cells. After the analysis of the cell viability using Cell Counting kit-8 (CCK-8) assay, we determined that the optimum levels were $200{\mu}M$ DAS, $25{\mu}M$ CAP, $50{\mu}M$ GGR, and $12.5{\mu}M$ SFN. Antioxidant enzymes were measured and protein expression was detected by Western blotting. All treatments showed a significant decrease in antioxidant enzyme activity such as superoxide dismutase, catalse, and glutathione peroxidase in HepG2 cells. Additionally, DAS, CAP, GGR and SFN increased the antioxidant system-related transcription factor Nrf2 which was found to be regulated by the activation of MAPK-JNK in this study. In conclusion, these results indicate the protective effects of DAS CAP, GGR, and SFN against $H_2O_2$-induced oxidative stress.

• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.36-42
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• 2020

In order to investigate the effect of the oxidation process on thermal properties of the pitch, the oxidized pitch was prepared by changing the oxidation temperature. Thermal properties of the pitch were analyzed using thermogravimetric analysis (TGA), and it divided into three sections as A (25~100 ℃), B (250~550 ℃) and C (550~800 ℃) by derivative thermogravimetry (DTG) graph behavior. In the A section, the was reduced because the moisture contained in the pitch was removed. In the B section, as the oxidation temperature increased, the thermal stability of the pitch is improved. Because the degree of aromaticity and molecular weight of the pitch increased with increasing oxidation temperature. In contrast, the results of the C section were shown opposite of B section. Because the introduced C-OH, C-O-C, and C=O bonds were decomposed, and the resulting oxygen compounds induced the combustion reaction of the pitch.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1479-1484
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• 2014

Based on the full optimized molecular geometric structures at B3LYP/cc-pvtz method, a new designed compound, 4,6,8-trinitro-4,5,7,8-tetrahydro-6H-furazano[3,4-f ]-1,3,5-triazepine was investigated in order to look for high energy density compounds (HEDCs). The analysis of the molecular structure indicates that the seven-membered ring adopts chair conformation and there exist intramolecular hydrogen bond interactions. IR spectrum and heat of formation (HOF) were predicted. The detonation velocity and pressure were evaluated by using Kamlet-Jacobs equations based on the theoretical density and condensed HOF. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that $N_1-N_6$ bond is the trigger bond. The crystal structure obtained by molecular mechanics belongs to $Pna2_1$ space group, with lattice parameters Z = 4, a = 15.3023 ${\AA}$, b = 5.7882 ${\AA}$, c = 11.0471 ${\AA}$, ${\rho}=2.06gcm^{-3}$. In addition, the analysis of frontier molecular orbital shows the title compound has good stability and high chemical hardness.

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.365-375
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• 2019

Background: Oxidative stress plays an important role in neuro-degenerative disorders such as Alzheimer's disease. Oxidative stress is mediated by reactive oxygen species (ROS), which are implicated in the pathogenesis of numerous diseases, and account for the toxicity of a wide range of compounds. Methods and Results: In order to study the neuro-protective effect of the complex extracts of Aster scaber Thunberg (AS) and Chaenoleles sinensis Koehne (CSK) against hydrogen peroxide in PC12 cells, cell viability was evaluated by the MTT assay using tetrazole, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and the intracellular ROS levels were determined the by 2',7'-dichlorofluorescein diacetate (DCF-DA) assay. In order to examine the anti-amnesic effects of the complex extracts of AS and CSK, behavioral tests were performed on male ICR mice. The ameliorating effect of the complex extracts against Aβ_1-42-induced learning and memory impairment was analyzed by y-maze and passive avoidance tests. The AS and CSK extracts showed neuro-protective activity both in vitro and in vivo, and the neuro-protective effect of their 60 : 40 (AS : CSK) mixture was better than that of the other mixtures. Moreover, the complex extracts synergistically inhibited acetylcholinesterase activity and rapid peroxidation. Conclusions: A mixture of the AS and CSK extracts could be used to develop functional foods and serve as raw materials for the development of therapeutics against Alzheimer's disease.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1781-1786
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• 2007

Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.20-27
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• 2010

Deer velvet antler was subjected to the extraction process using boiling water at three different temperatures (100, 110 and $120^{\circ}C$) and 70% ethanol solution. Functional components such as uronic acid, sulfated-glycosaminoglycans (sulfated-GAGs) and sialic acid in the extracts were analyzed, and their antioxidant activities were investigated using several in vitro models. Uronic acid and sulfated-GAGs content of each extract significantly decreased with increasing extraction temperature (p<0.05), while the residues obtained from the upper and middle part of the antler had a higher uronic acid content than the residues obtained from the base section. Sialic acid contents were highest in compounds extracted at $110^{\circ}C$, followed by 120 and $100^{\circ}C$. The 70% ethanol extracts also had a high levels of uronic acid content, but not for sulfated-GAGs and sialic acid. All extracts showed good antioxidant ability in a dose-dependant manner, with the $100^{\circ}C$ residue exhibiting the strongest activity compared to the 110 and $120^{\circ}C$ extracts. In relation to the hydroxyl radical scavenging activity and reduction power, the 70% ethanol extract exhibited the strongest activity. Furthermore, the velvet antler extracts inhibited apoptosis in hydrogen peroxide-induced PC-12 cells.