• Korean journal of food and cookery science
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• v.16 no.6
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• pp.629-639
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• 2000

The study was carried out to compare the antioxidant activities of products from caramel-type-browning reaction of xylose(XY), glucose(GL), sucrose(SU), glucose + citric acid (GLCA), glucose + sodium citrate(GLSC), glucose + glycine(GLGC) heated at 80, 120 or 140$^{\circ}C$ for 24 hr. 1. The hydrogen donating ability (HDA) of browning reaction products was generally enhanced as the browning temperature and time increased. The HDAs of the browning reaction products heated at 80$^{\circ}C$ for 24 hr were in the order of GLSC (0.387) > GLSC (0.362) > GLCA (0.301) > GL (0.299) > XY (0.290) > SU (0.281). But they were in the order of GLSC (0.543) > SU (0.328) > GL (0.309) > GLGC (0.325) > XY (0.298) > GLCA (0.275) under the condition of heating at 140$^{\circ}C$ for 24 hr. 2. The antioxidant activities of the anhydrous ethanol extracts of the browning mixtures were inferior to that of TBHQ as measured in com oil, but SU was superior to tocopherol in its antioxidant activity. All the browning mixtures showed antioxidant activities when heated at 80$^{\circ}C$; however, only SU and GLCA showed the activites at 120 or 140$^{\circ}C$. And the antioxidant activity of the SU extract was higher than that of TOCO. The antioxidant activities of the ethanol extracts were in the order of TBHQ > GLCA > GLGC > TOCO > SU > XY > GL > GLSC > control at 80$^{\circ}C$, TBHQ > SU > TOCO > GLCA > control > GLSC> XY > GL > GLGC at 120$^{\circ}C$, and TBHQ > SU > TOCO > GLCA > control > GLSC > GLGC > XY > GL at 140$^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.28 no.1
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• pp.60-65
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• 2015

Mushrooms (Pleurotus ostreatus) have been used as traditional remedies as well as food sources. This study particularly used an extract of Pleurotus ostreatus among many other mushrooms for research to figure out the antioxidant activity and an effect of cytotoxin. The result of antioxidative effect was significantly increased at the high concentration. The otal contents of polyphenol and flavonoid were $30.2{\pm}0.7$ and $20.4{\pm}0.6$ respectively. Both reducing power and DPPH radical scavenging activities are highest at 5.0 mg/mL of concentration. According to the research about cytotoxin of normal cell, an extract of Pleurotus ostreatus showed no existence of toxicity based on 80.5% of viability. Meanwhile, Pleurotus ostreatus is not strongly effective on the growth of cancer cell, indicating anti-cancer effect has a quite high range of viability up to $70.0{\pm}5.3%$ in 5 mg/mL of concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.127-135
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• 1986

Each molecular weight (Mw) fraction of melanoidins prepared from a D-glucose and glycine system, i. e., Mw below 1,000, Mw between 1,000 to 5,000 and Mw above 5,000 and nondialyzable and ozone-treated melanoidins were reacted with heat-induced mutagens such as Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 and IQ at $37^{\circ}C$ for 30 min. The inhibitory effects of the melanoidins on the mutagens increased with increasing molecular weight. The reducing ability ana antioxidative activity of melanoidins also increased in proportion to the increase in molecular weight, whereas the mutagenic inhibitory effect decreased on reduction of the melanoidins with sodium borohydride. It was also observed that a part of Trp-P-1 was adsorbed to melanoidin molecules. On modification of amino groups of these mutagens with carbonyl compounds derived through the Maillard reaction such as diacetyl and glyceraldehyde, their mutagenic activities were remarkably suppressed. Accordingly, it is speculated that the mutagenic inhibitory action of melanoidins is due to their reducing ability and antioxidative activity, and electrostatic binding and carbonyl groups of the melanoidin molecules.

• Journal of Technologic Dentistry
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• v.39 no.4
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• pp.253-259
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• 2017

목적: 이 실험의 목적은 한국 백삼과 캐나다 백삼의 일반 성분 분석, 항산화력 측정 및 치아 우식 유발균에 미치는 항균 효과를 비교 분석하는데 있다. 방법: 한국 백삼과 캐나다 백삼의 일반 성분은 수분정량, 조지방, 조단백질, 그리고 조회분의 분야에서 측정되었다. 두 백삼을 60% 에탄올에 추출시켜 환원당과 DPPH-scavenging assay를 통해 항산화력을 측정했다. 동일 추출물을 이용, 치아 우식균인 streptococcus mutans에 대해 디스크 확산법과 최소저해농도 측정을 실시해 항균력을 측정 및 비교했다. 결과: 실험 결과, 한국 백삼과 캐나다 백삼은 유사한 조지방, 조단백질, 조회분 성분을 갖고 있었으나 수분정량에서 캐나다백삼이 우세했다. 항산화력 실험에서는 캐나다 백삼이 DPPH- scavenging 능력에서 더 높았으나 환원당 실험과 총 페놀 함량에서는 한국 백삼의 수치가 더 높았다. 디스크 확산법을 통한 항균력 실험에서는 한국 백삼이 캐나다 백삼보다 더 넓은 clearing zone을 형성하고 더 낮은 최소저해농도를 달성해 항균력에서 우세했다. 결론: 한국 백삼과 캐나다 백삼은 비슷한 일반성분과 항산화력을 가졌다. 하지만 한국백삼이 치아 우식 유발균인 streptococcus mutans에 대한 항균력에서 더 우세했다.

• Journal of Mushroom
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• v.18 no.3
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• pp.244-253
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• 2020

The aim of this study was to investigate the biological activity of extracts obtained from the mycelium, sclerotium, and fruiting body of Wolfiporia cocos using different extraction solvents (hot water, 70% ethanol, and 70% methanol). Among the three developmental stages, the mycelium extracts showed the highest DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, ferric reducing antioxidant power (FRAP), nitrite scavenging activity, and total polyphenolic content. Among the extraction solvents in the context of the W. cocos mycelium, the DPPH radical scavenging activity, FRAP, and total polyphenol content in the hot-water extracts were significantly higher than those in the other extracts. In the case of the sclerotium, the reducing power, nitrite scavenging activity, and total polyphenol content were significantly higher in 70% ethanolic extracts. The fruiting body showed the highest DPPH radical scavenging activity, reducing power, nitrite scavenging activity, and total polyphenol content in the context of hot-water extraction. Moreover, the β-glucan content was significantly higher in the sclerotium versus the mycelium or fruiting body. The total amino acid and total essential amino acid contents were remarkably higher in the mycelium and fruiting body than in the sclerotium; of note, and arginine (Arg) and phenylalanine (Phe) were highly detected among the amino acid components.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.37-43
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• 1994

Mononitrotoluenes were reduced to aminotoluenes using porphyrin as a catalyst in the presence of several types of reductants including hydrogen sulfide and 1, 4-dithiothreitol(DTT). Intermediates and final products of porphyrin-catalyzed reduction of mononitrotoluenes were identified and a pathway for the reduction of the nitro group to the corresponding amino group was proposed. The optimum pH for the reduction was determined. The catalytic activity of the porphyrin was confirmed by UV/VIS absorption spectra and basic kinetics of porphyrin-catalyzed reduction were studied. Of several types of reductants tested, DTT sodium hydrosulfite, and hydrogen sulfide were seen to give significant reduction of nitrobodies. When hydrogen sulfide was used as a reductant hydrogen sulfide and nitrotoluenes were removed simultaneously.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.807-811
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• 2009

In this study, the antioxidant compounds and antioxidant activities of Geumjong brown rice were measured to evaluate functional properties and to compare with white rice and Chuchung brown rice. The content of polyphenolics, flavonoids and $\gamma$-oryzanol were measured by spectrophometric methods and tocopherol and tocotrienol analyses were carried out by HPLC. ABTS and DPPH radical scavenging activity and reducing power were used to measure antioxidant activity. The extraction yield of Chuchung white rice, Chuchung brown rice, and Geumjong brown rice were 1.5, 2.3, and 3.5%, respectively. The high level of antioxidant activity (69.77 mg TEAC/100 g) and total polyphenolic content (69.1 mg gallic acid equivalents/100 g) were found in Geumjong brown rice, whereas the reducing power of Geumjong brown rice was lower than that of Chuchung brown rice.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.273-276
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• 2016

최근 single-layer $MoSe_2$와 같은 2차원의 TMD 화합물들이 물분해 광촉매로서 각광받고 있다. TMD 화합물 중 single-layer $MoSe_2$는 수소 발생 반응을 일으킬 수 있으나 산소 발생 반응은 일으킬 수 없어 산화 반응을 진행시킬 추가적인 전극이 필요하다. 이 연구에서는 strain과 doping을 통해 valence band를 아래로 이동시켜 $MoSe_2$를 더 좋은 물분해 광촉매로 변화시키는 방법을 모색하였다. 먼저 Armchair, zigzag, biaxial isotropic, z-axis direction으로 strain을 걸어줄 때 전자구조의 변화를 관찰하였다. z-axis 방향으로 -2.5% strain을 걸어주었을 때 VBM이 0.07eV만큼 감소하였다. 또한 Mo를 Nb로 치환하고 Se를 P, As로 치환한 다음 전자구조를 관찰하였다. Nb와 doping의 경우 VBM이 감소함을 확인하였으며 As doping의 경우 산화반응이 일어날 수 있고 산화력과 환원력이 비슷해짐을 알아내었다. 또한 산화반응과 환원반응이 일어나는 위치가 분리됨을 확인하였다.

• Food Science and Preservation
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• v.17 no.4
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• pp.541-546
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• 2010

Wild-garlic (Allium victorialis L.) is a perennial plant found in worldwide and has been considered as a favorite vegetable due to its particular smell and taste. However, the study of biological activity of wild-garlic and the development of processed food are in rudimentary. In this study, we evaluated several biological activities, including antioxidant, antimicrobial, and inhibitory activities against human thrombin, $\alpha$-amylase and $\alpha$-glucosidase, of Ulrung wild-garlic. Analysis of the composition showed that Ulrung wild-garlic is nutritive although it is perishable. The color of fresh juice was stably maintained during 10 days-storage at $4^{\circ}C$, but rapidly discolored by heat treatment at $70^{\circ}C$ for 1 h. During heat treatment, the contents of total sugar and total polyphenol were decreased to 75% and 50%, respectively, and acidity was increased from 0.069% to 0.111%. In a while, the brix, reducing sugar, and total flavonoids showed minor changes. The fresh juice showed strong DPPH scavenging activity, reducing power and antibacterial and antifungal activity, but the heat-treated juice lost the antioxidant and antimicrobial activities. The inhibitory activities against human thrombin and $\alpha$-amylase and $\alpha$-glucosidase was negligible in both fresh juice and heat-treated juice. These results suggested that the antioxidant and antimicrobial components in wild-garlic are heat-liable and volatile. Based on our results, we propose non-heat treatment products for processed wild-garlic, for example, fresh juice-added beverage or fermented liquors using wild-garlic.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.216-216
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• 1994

안트라싸이클린계 항암항생제의 부작용 발생기전으로는 C-고리의 퀴논 부위에 전자가 전달되어 퀴논고리가 환원되는 과정이 제시되고 있으며 그중 하나의 전자가 전달되어 생성되는 활성산소(activated oxygen)가 심장독성과 관련이 있는 것으로 알려져 있다. 이 때 퀴논고리의 환원력(전자흡수능력)이 C-고리 자체의 변환, 또는 인접 B-고리에 도입된 치환체의 영향으로 억제될 수 있다는 보고를 이론적 근거로 하여 안트라싸이클리논 골격을 전자흡수능력을 가진 acridone 골격으로 치환한 9-ethynyl-6,9-trihydroxy-7,8,9,10-tetrahydro-benzo〔b〕acridone을 합성하였으며 이를 daunosamine과 축합하기 위하여 $C_{7}$위치에 OH기를 도입한 화합물로 변환하였다.