• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2001년도 춘계학술발표논문집
• /
• pp.18-25
• /
• 2001

A new wood-degrading fungus Trichophyton rubrum LKY-7 secretes a high level of laccase in a glucose-peptone liquid medium. The production of laccase by the fungus was barely induced by 2,5-xylidine. The laccase has been purified to homogeneity through three chromatography steps in an overall yield of 40%. The molecular mass of the purified laccase was about 65 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified laccase had the distinct blue color and had basic spectroscopic features of a typical blue laccase: two absorption maxima at 278 and 610 nm and a shoulder at 338 nm. The N-terminus of the laccase has been sequenced, revealing high homology to laccases from wood-degrading white-rot fungi such as Ceriporiopsis subvermispora. The enzyme had a "low" redox potential (0.5 V vs normal hydrogen electrode), yet it was one of the most active laccases in oxidizing a series of representative substrates/mediators. Compared with other fungal laccases, the laccase has a very low Km value with ABTS [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid] as a substrate and a very high Km value with violuric acid as a substrate. The laccase has the isoelectric point of 4.0. The laccase had very acidic optimal pH values (pH 3-4) while it was more stable at neutral pH than at acidic pH. The laccase oxidized hydroquinone faster than catechol and pyrogallol. The oxidation of tyrosine by the laccase was not detectable under the reaction conditions. The laccase was strongly inhibited by sodium azide and sodium fluoride. fluoride.

• 한국물환경학회지
• /
• 제21권2호
• /
• pp.153-157
• /
• 2005

The purpose of this study was to find out the effect of oxidation by-products for the formation of haloacetic acid (HAA) during ozonation. The phenol was used as a model precursor of HAA, and its oxidation by-products, such as hydroquinone, catechol, glyoxal, glyoxylic acid and oxalic acid were investigated to find out how much HAA formation potential (HAAFP) they have. As the result, among the phenol and its oxidation by-products, the highest reactivity with chlorine was found from the phenol, showing the highest HAAFP. Even though the tested by-products had a lower HAAFP than phenol, it was confirmed that all of them can act as the precursor of HAA. From the ozonation of phenol-containing water, it was found that the efficiency of ozone in controlling of HAAs can be reduced due to the oxidation by-products. In addition, the ozonation of HAAFP was performed under the both pH conditions (acid and base), and the result indicates that OH radical play a important role to decrease HAAFP.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.115-115
• /
• 2011

Nano hybrid superlattices consisting of organic and inorganic components have great potential for creation of new types of functional material by utilizing the wide variety of properties which differ from their constituents. They provide the opportunity for developing new materials with new useful properties. Herein, we fabricated new type of organic-inorganic nano hybrid superlattice thin films by a sequential, self-limiting surface chemistry process known as molecular layer depostion (MLD) combined with atomic layer deposition (ALD). An organic layer was formed at $150^{\circ}C$ using MLD with repeated sequintial adsorption of Hydroquinone and Titanium tetrachloride. A $TiO_2$ inorganic nanolayer was deposited at the same temperature using ALD with alternating surface-saturating reactions of Titanium tetrachloride and water. Using UV-Vis spectroscopy, we confirmed visible light absorption by LMCT. And FTIR spectroscopy and XPS were employed to determine the chemical composition. Ellipsometry and TEM analysis were also used to confirm linear growth of the film versus number of MLD cycles at all same temperature. In addition, p-n junction diodes domonstrated in this study suggest that the film can be suitable for n-type semiconductors.

• 한국환경과학회지
• /
• 제25권5호
• /
• pp.695-703
• /
• 2016

The purpose of this study was to measure the bioactivity and antioxidant activity of Orostachys japonicus A. Berger. Orostachys japonicus A. Berger have been known to contain functional materials such as kaempferol, hydroquinone, methyl gallate, quercetin, gallic acid etc. To identify the main functional materials of Orostachys japonicus A. Berger, the contents of flavonoid and phenol were measured. We extracted Orostachys japonicus A. Berger powder from four solvents such as chloroform:methanol (CM, 2:1, v/v), distilled water (DW), 70% methanol, 70% ethanol. After that, this study determined tannin, total phenol, flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power and reducing power of Orostachys japonicus A. Berger extracts and as results of comparing each extract. respectively. From the above results shows that antioxidant activity and bioactivity of Orostachys japonicus A. Berger extracts was higher in the order of 70% ethanol, 70% methanol, DW and CM (p<0.05). The results showed that antioxidant activity of Orostachys japonicus A. Berger extracts supposed to affect by the total phenol and flavonoid contents.

• Bulletin of the Korean Chemical Society
• /
• 제16권5호
• /
• pp.416-421
• /
• 1995

The approximate rates and stoichiometry of the reaction of excess lithium gallium hydride with selected organic compounds containing representative functional groups were examined under the standard conditions (diethyl ether, 0 $^{\circ}C)$ in order to compare its reducing characteristics with lithium aluminum hydride and lithium borohydride previously reported, and enlarge the scope of its applicability as a reducing agent. Alcohols, phenol, and amines evolve hydrogen rapidly and quantitatively. However lithium gallium hydride reacts with only one active hydrogen of primary amine. Aldehydes and ketones of diverse structure are rapidly reduced to the corresponding alcohols. Conjugated aldehyde and ketone such as cinnamaldehyde and methyl vinyl ketone are rapidly reduced to the corresponding saturated alcohols. p-Benzoquinone is mainly reduces to hydroquinone. Caproic acid and benzoic acid liberate hydrogen rapidly and quantitatively, but reduction proceeds slowly. The acid chlorides and esters tested are all rapidly reduced to the corresponding alcohols. Alkyl halides and epoxides are reduced rapidly with an uptake of 1 equiv of hydride. Styrene oxide is reduced to give 1-phenylethanol quantitatively. Primary amides are reduced slowly. Benzonitrile consumes 2.0 equiv of hydride rapidly, whereas capronitrile is reduced slowly. Nitro compounds consumed 2.9 equiv of hydride, of which 1.9 equiv is for reduction, whereas azobenzene, and azoxybenzene are inert toward this reagent. Cyclohexanone oxime is reduced consuming 2.0 equiv of hydride for reduction at a moderate rate. Pyridine is inert toward this reagent. Disulfides and sulfoxides are reduced slowly, whereas sulfide, sulfone, and sulfonate are inert under these reaction conditions. Sulfonic acid evolves 1 equiv of hydrogen instantly, but reduction is not proceeded.

• Journal of the Korean Wood Science and Technology
• /
• 제26권3호
• /
• pp.53-62
• /
• 1998

In this research, 7 species of white rot fungi were used for determining the resistance against pentachlorophenol (PCP). Three fungi with good PCP resistance were selected for evaluating the biodegradability, and biodegradation mechanism by HPLC and GC/MS spectrometry. Among 7 fungi, there were significant differences on PCP resistance on 4 different PCP concentrations. In the concentrations of 50 and 100ppm ($\mu$g of PCP per g of 2% malt extract agar), most fungi were easily able to grow, and well suited to newly PCP-added condition, but in that of more than 250ppm, the mycelia growths of Ganoderma lucidum 20435, G. lucidum 20432, Pleurotus ostreatus, and Daldinia concentrica were significantly inhibited or even stopped by the addition of PCP to the culture. However, Trametes versicolor, Phanerochaete chrysosporium, and Inonotus cuticularis still kept growing at 250ppm, indicating the potential utilization of wood rot fungi to high concentrated PCP biodegradation. Particularly, P. chrysosporium even showed very rapid growth rate at more than 500ppm of PCP concentration. Three selected fungi based on the above results showed an excellent biodegradability against PCP. P. chrysosporium degraded PCP up to 84% on the first day of incubation, and during 7 days, most of added PCP were degraded. T. versicolor also showed more than 90% of biodegradability at 7th day, and even though the initial stage of degradation was very slow, I. cuticularis has been approached to 90% at 21 st day after incubation with dense growing pattern of mycelia. Therefore, the PCP biodegradability was definitely dependent on the rapid suitability of fungi to newly PCP-added condition. In addition, the PCP biodegradation by filtrates of P. chrysosporium, T. versicolor, and I. cuticularis was very minimal or limited, suggesting that the extracellular enzyme system may be not so significantly related to the PCP biodegradation. Among the biodegradation metabolites of PCP, the most abundant one was pentachloroanisole which resulted in a little weaker toxicity than PCP, and others were tetrachlorophenol, tetrachloro-hydroquinone, benzoic acid, and salicylic acid, suggesting that PCP may be biodegraded by several sequential reactions such as methylation, radical-induced oxidation, dechlorination, and hydroxylation.

• 한국잡초학회지
• /
• 제17권4호
• /
• pp.421-430
• /
• 1997

채취시기(採取時期)를 달리한 초록과 노란은행잎으로부터의 수용추출물(水溶抽出物)에 대한 벼, 피, 바랭이 및 상추의 제초활성검정(除草活性檢定)과 지방산(脂肪酸) 성분(成分)과 페놀성 물질(物質)을 분리(分離) 동정(同定)하여 얻어진 결과(結果)는 다음과 같다. 1. 은행잎 수용(水溶) 추출물(抽出物)은 벼, 피, 바랭이, 상추의 발아(發芽)와 생육(生育)을 크게 억제(抑制)시켰으며, 특히 20% 수용추출액(水溶抽出液)인 경우는 억제효과(抑制效果)가 뛰어났다. 초록과 노란은행잎 수요 추출물간의 생리활성정도는 별 차이가 없었다. 2. 은행잎의 지방산(脂肪酸)을 검정(檢定)한 결과(結果), 지방산(脂肪酸)이 검정(檢定)되었으며, 그 중에서도 Linolenic acid, Palmitic acid가 많이 포함(包含)되어 있었다. 또한 계절에 따라 은행잎에 함유(含有)된 지방산(脂肪酸)의 함량(含量)이 다소 변화(變化)함을 알 수 있었다. 3. GLC로 phenolic acids를 동정(同定)한 결과(結果), 모든 fraction에서 Salicylic acid의 높은 비율(比率)을 관찰(觀察)할 수 있었으며, 또한 p-coumaric acid, phloroglucinol 등도 검정(檢定)되었다.

• Journal of Plant Biology
• /
• 제2권1호
• /
• pp.1-12
• /
• 1959

1) The comparative studies of the quantitative measurement of growth characteristics and utilization of substrates by Euglena gracilis var. bacilla 10616 in the light and in darkness have been carried out. Eodogenous respiration, effect of respiratory inhibitors and responses to the added substrates for the exogenous respiration are also investigated. 2) All cultures are grown in the open air under the continuous illumination of fluorescent light of 3500 lux at room termperature, the growth rate of the culture in the basal medium added 0.5% lactate is found to be the highest. The growth rate decreases successively for the cultures of 0.5% sucinate, 0.5% Na-acetate, 0.5% malate, and control. There is no growth in the basal meidum added 0.5% butyrate and 0.5% hydroquinone. The similar results are obtained for the mentioned cultures in the darkness. However, the growth rate in basal medium added 0.5% glucose and 0.5% sucrose does seem to increase in the darkness unlike the illumination. 3) The endogenous rate of respiration for the organism cultured photosynthetically is about 12.94ul 02/mg/hr, in basal medium and the respiratory quotient is about 0.84. The rate is decreased by starvations to 6.5ul 02/mg/hr, about to a half, but the respiratory quotient does net change. 4) The oxygen consomption during initial 2 hours in suspending solution ranging from pH 4.5 to pH 9.3 is highest at pH 4.5 in which the algae had grown, at pH 5.5 and at pH 6.9. 5) Endogenous respiration of the cells is strongly inhibited by 0.1M of potassium cyanide, malomic acid, sodium fluoride and iodo-acetic acid. It is also strongly inhibited by 0.01M of potassium cyanide. 6) The respiratory response to added substrates for the exogenous respiration in the organism is coincided with the rate in the basal medium added the substrate in light and in darkness, whether the cells are fed or starved. 7) According to the results of this study, there seems to be the flexibility of the interconversion between photosynthesis and chemosynthesis, heterotropic mode of metabolism, in Euglena gracilis var. bacillaris, and that this organism utilizes the lactate most. It also may be suggested that the enayme systems linked in the each steps of Embden-Myerhof-Parnas path way and TCA cycle seem to exist in this organism.

• Applied Biological Chemistry
• /
• 제17권3호
• /
• pp.149-176
• /
• 1974

팔종(八種)의 치환(置換) diphenyl ether 제초제(除草劑)를 Rayonet 광화학(光化學) 반응기(反應器)를 사용(使用)한 모조환경조건하(模造環境條件下)에서 용액상(溶液相) 광분해(光分解)시켜 그 분해산물(分解産物)에 관(關)하여 연구(硏究)하였다. 시료(試料)로 사용(使用)된 화합물(化合物)들은 300 nm에서 광화학반응(光化學反應)을 일으키기에 충분(充分)한 energy를 흡수(吸收)하였으며 분해산물(分解産物)은 tlc, glc, ir, ms, 그리고 nmr 등(等)에 의(依)하여 확인(確認)하였다. 그 결과(結果)를 요약(要約)하면 C-6989의 용액상(溶液相) 광분해(光分解) : p-nitrophenol이 다량(多量) 생성(生成)됨을 보아 ether결합(結合)의 결렬이 주반응(主反應)이며 치환기(置換基) $NO_2{\rightarrow}NH_2$의 광화학적(光化學約) 환원반응(還元反應)과 $CF_3{\rightarrow}COOH$의 산화반응(酸化反應)도 관찰되었다. p-Nitrophenol의 수중(水中) 광분해(光分解) : quinone(0.28%), hydroquinone(0.66%) 및 p-aminophenol(0.42%)과 비교적(比較的) 소량(少量)의 미지화합물(未知化合物)이 생성(生成)됨을 확인(確認)하였고 모화합물(母化化合物)은 대부분(大部分) 작용(作用)을 받지 않은 채로 존재(存在)하였다. 이들 분해산물(分解産物)의 형성기구(形成機構)는 $n{\rightarrow}{\pi}^*$ 및 여기(勵起)를 거친 nitro-nitrite재배열(再配列) 및 자유기(自由基)에 의(依)한 수소탈취(水素脫取)를 통(通)한 광환원(光還元)으로 추측(推測)되었다. Nitrofen의 용액상(溶液相) 광분해(光分解) : n-hexane중(中)에서는 $NO_2$기(基)의 광환원(光遷元)이 주반응(主反應)이었고 수용액(水溶液) 중(中)에서는 광환원(光遷元) 및 hydroxylation이 ether결합(結合) 결렬 보다 현저하였다. hydroxide ion에 의한 친핵적(親核的) 치환(置換), hydroxyl기(基) 및 소량(少量)이긴 하지만 수소(水素)에 의한 염소(鹽素)의 치환(置換)도 다소 관찰되었다. MO-338의 용액상(溶液相) 광분해(光分解) : n-hexane용액중(中) nitro기(基)의 광환원(光遷元) 반응(反應)과 수용액중(水溶液中)에서의 광환원(光遷元) 및 hydroxylation이 주반응(主反應)이었으며 hydroxyl기(基)와 수소(水素)에 의(依)한 염소(鹽素)의 치환(置換) 및 ether결합(結合)의 결렬도 볼 수 있었다. n-Hexane과 cyclohexane중(中)에서의 MC-4379, MC-3761, MC-5127, MC-6063 및 MC-7181의 광분해(光分解) : nitro기(基)의 광환원반응(光還元反應)과 수소(水素)에 의(依)한 halogen의 치환반응(置換反應)이 주(主)로 일어났다. MC-4379의 수중(水中) 광분해(光分解) : ether결합(結合)의 결렬, hydroxyl기(基)에 의한 carboxymethyl기(基)의 치환(置換), hydroxylation, hydroxyl기(基)에 의한 nitro기(基)의 치환(置換)이 주(主)로 일어났고 광환원(光還元) 및 광염소화반응(光鹽素化反應)도 약간 일어났다. MC-3761의 수중(水中) 광분해(光分解) : ether결합(結合)의 결렬, hydroxyl기(基)에 의한 carboxymethyl기(基)의 치환(置換) 및 hydroxylation이 수반되는 광환원(光還元)이 주반응(主反應)이었다. MC-5127의 수중(水中) 광분해(光分解) : 수소(水素)에 의한 carboxyethyl기(基)의 치환(置換)이 현저 하였고 ether결합(結合)의 결렬, 광환원(光還元) 및 탈염소화반응(脫鹽素化反應)도 약간 관찰되었으며 decarboxyethylation은 decarxy-methylation보다 용이함을 볼 수 있었다. MC-6063의 수중(水中) 광분해(光分解) : ether결합(結合)의 결렬과 탈염소화반응(脫鹽素化反應)이 주(主)로 관찰되었다. MC-7181의 수중(水中) 광분해(光分解) : 수소(水素)에 의한 carboxymethyl기(基)의 치환(置換)과 monodechlorination이 현저하였고 ether결합(結合) 결렬과 hydroxylation도 약간 일어났다. 3-Carboxymethyl-4-nitrophenol의 수중(水中) 광분해(光分解) : 방향족(芳香族) ester에서 흔히 볼 수 있는 광유도(光誘導) Fries rearrangement는 이 화합물(化合物)의 carboxymethyl기(基)에서는 볼 수 없었고 $nitro{\to}nitroso$반응(反應)이 주(主)로 일어났다.

• Toxicological Research
• /
• 제27권3호
• /
• pp.153-160
• /
• 2011

To evaluate the whitening effect of black tea water extract (BT), BT was topically applied to artificially hyperpigmented spots on the back skins of brown guinea-pigs (weight: 450~500 g) induced by 1,500 mJ/$cm^2$ of ultraviolet B (UVB) irradiation. The test compounds of 30 ${\mu}l$ were applied twice a day, six days a week, for four weeks. The artificially hyperpigmented spots were divided into 5 groups: control (UVB + saline, C), vehicle control [UVB + propylene glycol: ethanol: water (5 : 3 : 2), VC], positive control (UVB + 2% hydroquinone, PC), experimental 1 (UVB + 1% BT), experimental 2 (UVB + 2% BT). After 4-week application, the spots were removed by biopsy punch under anesthetic condition and used as specimens for the histological examination. The total polyphenol and flavonoid contents of BT were 104 and 91 mg/g, respectively. The electron-donating ability of BT revealed a dose-dependent response, showing the excellent capacities of 86% at 800 ${\mu}g$/ml. The artificially hyperpigmented spots treated with the PC and BT were obviously lightened compared to the C and VC groups. At the fourth week, the melanin indices for the PC and BT groups were significantly lower (p < 0.001) than those of the C and VC groups. In histological examination, PC and BT groups were significantly reduced in the melanin pigmentation, the proliferation of melanocytes and the synthesis of melanosomes compared to the C and VC groups. It is found that BT inhibits the proliferation of melanocytes and synthesis of melanosomes in vivo using brown guinea pigs, thereby showing a definite skin whitening effect.