• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1043-1052
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• 1996

Supercritical fluid chromatographic method was recommended as an alternative separation method of fatty acids of the conventional method such as distillation or extraction. Although diffusion characteristics are varied by the carbon numbers and the degree of unsaturation of fatty acids, the quantitative data were so rare that the commercialization of supercritical fluid chromatographic method has been hindered. In this study, diffusion coefficients of fatty acids which are differently unsaturated are measured by CPB method in the range of 308.15K to 328.15K and 13MPa to 17MPa in supercritical carbon dioxide. A decrease in the binary diffusion coefficient was observed with an increase in temperature and pressure. Also, the decrease in the binary diffusion coefficient with increasing fluid density and viscosity. Wilke-Chang equation, Funazukuri empirical equation, and Matthews-Akgerman equation are used to correlate the experimental diffusion coefficients of fatty acids in supercritical carbon dioxide. Among the various theoretical equations, Matthews-Akgerman equation based on RHS theory was suggested as a more successful correlation model with experimental data.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.301-307
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• 1999

When fats are irradiated, hydrocarbons contained one or two fewer carbon atoms are formed from the parent fatty acids. A method to detect radiation-induced hydrocarbons consists of the extraction of fat from beef, pork and chicken, separation of hydrocarbons with a florisil column and identification of GC/MS methods. When beef, pork and chicken were irradiated, pentadecane, 1-tetradecene, heptadecane, 1-hexadecene, 8-heptadecene, 1,7-hexadecadiene, 6,9-heptadecadiene and 1,7,10-hexadecatriene were formed from palmitic, stearic, oleic and linoleic acids. Concentrations of the produced hydrocarbons tended to increase linearly with the dose levels of irradiation. Concentrations of hydrocarbons produced by ${\gamma}-irradiation$ depended upon the composition of fatty acids in beef, pork and chicken. The major hydrocarbons in irradiated beef, pork and chicken were 1,7-hexadecadiene and 8-heptadecene originating from oleic acid. 1,7-Hexadecadiene was the highest amount in irradiated beef, pork and chicken.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.805-809
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• 2008

The objective of this study was to compare the aroma characteristics and antioxidant activity of Chrysanthemum indicum Linne (CIL), C. morifolium Ramat (CMR) and C. zawadskii var Latilobum (CZL). The volatile compounds were extracted by simultaneous steam distillation extraction and identified with gas chromatography/mass spectrometer. The major volatile compounds of Chrysanthemum sp. were camphene, 1,8-cineole, benzene, pinocarvone, bicyclo-2,2,1-heptan-2-ol, ${\beta}$-caryophyllene, 3-cyclohexen-1-ol, ${\gamma}$-curcumene, zingiberene and ${\beta}$-bisabolene. The DPPH radical scavenging activity (EDA, %) of volatile compounds in CIL, CMR and CZL were 30.57, 46.36, and 51.72%/g sample, respectively. The ascorbic acid equivalent antioxidant capacity (AEAC) of volatile compounds were 34.99, 35.31, and 38.48 mg AEAC/g, respectively.

• Imaging Science in Dentistry
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• v.50 no.3
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• pp.199-208
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• 2020

Purpose: This study was performed to introduce an in vivo hybrid multimodality technique involving the coregistration of micro-computed tomography (micro-CT) and high-resolution magnetic resonance imaging (HR-MRI) to concomitantly visualize and quantify mineralization and vascularization at follow-up in a rat model. Materials and Methods: Three adult female rats were randomly assigned as test subjects, with 1 rat serving as a control subject. For 20 weeks, the test rats received a weekly intravenous injection of 30 ㎍/kg zoledronic acid, and the control rat was administered a similar dose of normal saline. Bilateral extraction of the lower first and second molars was performed after 10 weeks. All rats were scanned once every 4 weeks with both micro-CT and HR-MRI. Micro-CT and HR-MRI images were registered and fused in the same 3-dimensional region to quantify blood flow velocity and trabecular bone thickness at T0 (baseline), T4 (4 weeks), T8 (8 weeks), T12 (12 weeks), T16 (16 weeks), and T20 (20 weeks). Histological assessment was the gold standard with which the findings were compared. Results: The histomorphometric images at T20 aligned with the HR-MRI findings, with both test and control rats demonstrating reduced trabecular bone vasculature and blood vessel density. The micro-CT findings were also consistent with the histomorphometric changes, which revealed that the test rats had thicker trabecular bone and smaller marrow spaces than the control rat. Conclusion: The combination of micro-CT and HR-MRI may be considered a powerful non-invasive novel technique for the longitudinal quantification of localized mineralization and vascularization.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.4
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• pp.746-754
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• 1996

The purpose of this study was to evaluate the fracture strength of porcelain laminate veneer with various lingual extention length when incisal restoring. Sixty recently extracted, intact maxillary incisors were used and stored in a physiologic saline solution from the time of extraction. Seating form was preparation at the labial surface of each tooth with a water-cooled round diamond bur. Standard block was formed with 32 gauge and 24 gauge wax at tooth labial and lingual surface. Lingual extention length differed according to each group. (group I : 0.5mm, group II : 1 mm, group III : 2mm, group IV : 0mm) All tooth specimens were impressioned with examix(GC Inc., Japan). Refractory cast were maked with refractory die material(Ceramco Inc., U.S.A.) Laminate porcelain (Ceramco II Veneer porcelain, Ceramco Inc., U.S.A.) was condensed in refractory die cast and baked according to the manufacturer's recommendations. Each surface was contoured with low speed diamond bur according to guide block. All porcelain specimens were sandblasted and ultrasonically cleaned in distlled water for 3 minutes. Then, all porcelain specimen were etched with 8% hydrofluoric acid for 5 minutes. Sixty specimens were bonded with composite resin cement(Choice Porcelain Veneer System, Bisco Inc., U.S.A.) according to manufacture's directions. The fracture loads of the specimen were measured by Instron universal testing machine. The mean values of fracture loads for the groups were statistically compared by Duncan's multiful range test. The result were as follows : Mean fracture strengths of each group were 86.95Mpa in no lingual extention group, 44.98Mpa in 0.5mm lingual extention group, 27.47Mpa in 1mm lingual extention group, 19.61Mpa in 2mm lingual extention group. There was a statistically significant difference between all group(p<0.01).

• The Korea Journal of Herbology
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• v.26 no.3
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• pp.37-45
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• 2011

Objectives : This study focused on Schisandrae Fructus (SF) and Perilae Folium (PF), traditional medicine herbs and health functional food in Korea, Japan and China. We investigated various pharmacological activities that include a potential source of free radical scavenging, anti-viral, anti-microbial, anti-allergy and anti-inflammatory activities. Methods : We conducted an investigation of total contents of phenolic and flavonoid compounds in these single herbal extraction with/without combined to mixture. We also measured antioxidant activities such as DPPH free radical scavenging, SOD-like scavenging, nitrite scavenging and hydroxyl radical scavenging activities, xanthine oxidase inhibition, linoleic acid peroxidation inhibition, and reducing power. Results : As the results, contents of total phenoilc compounds and flavonoids were higher in those of PF than those of SF. Those of SF+PF mixture showed the synergy effects compared with those of SF and PF single extractions. Activities of DPPH free radical and SOD-like scavenging in 1 mg/mL concentration increased in dose dependent manners. That of SF increased compared with that of PF. That of SF and PF mixture also increased compared with that of BHA as a positive control. The other antioxident activities also showed similar to patten of activity of DPPH free radical scavenging. When combined to SF and PF extractions, there was showed synergic effect compared with those of BHA, excepted activities of xanthine oxidase inhibition and reducing power. Taken together, SF and PF have high phenolic and flavonoid compounds content furthermore, antioxidant activities in SF and PF mixture showed more synergy effect compared with those of BHA. Conclusions : Therefore, these findings suggest that SF and PF mixture may offer functional materials potential for development of functional beverage. But further studies are needed for the identification of the active compounds.

• Food Science and Preservation
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• v.19 no.5
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• pp.744-750
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• 2012

In this study, the optimal conditions for phenolic-compound extraction from medicinal plants were found to be 24 h and about 50% ethanol. The electron-donating scavenging activities (DPPH), ABTS radical-cation decolorization (ABTS), antioxidant protection factor (PF), and thiobarbituric acid reaction substance (TBAR) were measured to determine the antioxidant activities of the extracts of Sanguisorba officinalis Linn., Citrus unshiu Markovich, Melia azedarach L., Asparagus cochinchinensis Merr., Citrus unshiu S., Polygonum aviculare L., and Leonurus sibiricus L. The total phenolic contents of the extracts of medical plants were determined to be 0.45-3.00 mg/g in the water extracts and 0.33-3.15 mg/g in the 50% ethanol extracts. The electron-donating abilities (EDA) of the water and ethanol extracts were both above 85% at the $50{\mu}g/ml$ concentration. The ABTS radical-cation decolorization was above 80% at the $100{\mu}g/ml$ concentration in all the extracts of various medicinal plants. The antioxidant protection factor (PF) of the Melia azedarach L. extracts was found to be $1.65{\pm}0.40$ PF in the water extracts at the $100{\mu}g/ml$ concentration, and was higher than those of the other medicinal-plant extracts. The TBAR inhibition rates of all the medicinal-plant extracts, except Asparagus cochinchinensis Merr., were above 85% at the $100{\mu}g/ml$ concentration. These results confirmed that the various oriental medicinal plants (Sanguisorba officinalis Linn., Citrus unshiu Markovich, Melia azedarach L., Asparagus cochinchinensis Merr., Citrus unshiu S., Polygonum aviculare L., and Leonurus sibiricus L.) that were included in this study are useful functional-food sources.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.423-430
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• 2016

Background: The induction of cellular defensive genes such as phase II detoxifying and antioxidant enzymes is a highly effective strategy for protection against carcinogenesis as well as slowing cancer development. Transcription factor Nrf2 (nuclear factor E2-related factor 2) is responsible for activation of phase II enzymes induced by natural chemopreventive compounds. Methods: Red ginseng oil (RGO) was extracted using a supercritical $CO_2$ extraction system and chemical profile of RGO was investigated by GC/MS. Effects of RGO on regulation of the Nrf2/antioxidant response element (ARE) pathway were determined by ARE-luciferase assay, western blotting, and confocal microscopy. Results: The predominant components of RGO were 9,12-octadecadienoic acid (31.48%), bicyclo[10.1.0] tridec-1-ene (22.54%), and 22,23-dihydrostigmasterol (16.90%). RGO treatment significantly increased nuclear translocation of Nrf2 as well as ARE reporter gene activity, leading to upregulation of heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1. Phosphorylation of the upstream kinases such as apoptosis signal-regulating kinase (ASK)1, mitogen-activated protein kinase (MAPK) kinase (MKK)4/7, c-Jun N-terminal kinase (JNK), and p38 MAPK were enhanced by treatment with RGO. In addition, RGO-mediated Nrf2 expression and nuclear translocation was attenuated by JNK inhibitor SP600125 and p38 MAPK inhibitor SB202190. Conclusion: RGO could be used as a potential chemopreventive agent, possibly by induction of Nrf2/ARE-mediated phase II enzymes via ASK1-MKK4/7-JNK and p38 MAPK signaling pathways.

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.121-131
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• 2017

We evaluated the antioxidant properties of Lentinula edodes upon sawdust bag cultivation with 5 oak substrates: Quercus acutissima, Q. mongolica, Q. serrata, Q. aliena, and Q. variabilis. We found that the optimal extraction conditions were 70% (v/v) methanol shaken at 150 rpm at $25^{\circ}C$ and 150 rpm for 24 h. The methanolic extracts from L. edodes contained high phenolic and flavonoid contents, they also exhibited stronger antioxidant activities. The total phenolic contents and total flavonoid contents of the mushroom extracts ranged from 2.37 to 3.12 milligrams of gallic acid equivalents per gram of dried mushroom (mg GAE/g) and 0.48 to 0.48 milligrams of quercetin equivalents per gram of dried mushroom (mg QE/g), respectively. In addition, the mushroom extracts exhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (15.8% to 89.4%) at 2 to 10 mg/mL, ferric reducing antioxidant power (0.153 to 0.425) at 5 to 20 mg/mL, and reducing power (0.078 to 0.359) at 5 to 20 mg/mL, respectively. Q. aliena more effectively increased total phenolic contents, total flavonoid contents, and antioxidant activities than the other oak substrates.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.51-55
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• 2007

The fractions of Ulva lactuca were studied to verify the antioxidant activities. The fractions from the ethanol extract of U. lactuca were prepared by the systematic extraction procedure with the solvents such as hexane, ethyl ether, ethyl acetate, butanol and $H_2O$. Furthermore, ethyl ether, ethyl acetate and aqueous fractions of U. lactuca were purified using HPLC. The antioxidant activities of purified samples from ethyl ether, ethyl acetate, and aqueous fractions were investigated using 1,1-diphenyl-2-picryl-hydrazil (DPPH). L-ascorbic acid, a positive control showed the highest DPPH radical scavenging activity. In addition, purified sample from aqueous fraction also showed relatively high activity. Purified sample from ethyl acetate fraction showed moderate activity, but purified sample from ethyl ether fraction showed the lowest activity. Dose dependent patterns were observed on all three samples tested. The lipid peroxidation inhibition activities of these three purified samples were also investigated. Purified sample from ethyl ether fraction of U. lactuca showed the highest activity and as strong activity as that of $\alpha-tocopherol$, a positive control. These results suggest that U. lactuca may be a useful candidate for a natural antioxidant agent.