• 제목/요약/키워드: phenol-free

검색결과 232건 처리시간 0.024초

Isolation of a Pestalotiopsis Species Degrading Mucilage from Fruit of Opuntia ficus-indica var. Saboten

  • Huh, Yoon-Hee;Ko, Young-Hwan
    • Journal of Applied Biological Chemistry
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    • 제50권4호
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    • pp.221-226
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    • 2007
  • The high molecular-weight mucilage extracted and purified from cactus fruit of Opuntia ficus-indica var. Saboten was degraded by the cell-free culture filtrate of a fungus isolated from soil. TLC analysis of the polymeric mucilage after incubation with the fungal culture filtrate confirmed its degradation. When the degradation products were tested for their qualitative reactions with ninhydrin and phenol-sulfuric acid, only phenol-sulfuric acid gave positive development, and ninhydrin did not show any observable color reaction. This coloring reaction suggested the presence of a carbohydrate without an amino group within the mucilage. Analyses by HPLC and liquid gel permeation chromatography on sephadex G-100 also provided additional information on degradation of the mucilage by the fungal culture filtrate. The sequences of ITS-5.8S rDNA from the fungal isolate that was cultivated for the preparation of mucilage-degrading enzyme showed 99% similarity to those of Pestalotiopsis aquatica.

Melt-Grafting of Maleimides Having Hindered Phenol Group onto Polypropylene

  • Kim, Taek-Hyeon;Lee, Nam-Gun
    • Bulletin of the Korean Chemical Society
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    • 제24권12호
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    • pp.1809-1813
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    • 2003
  • Monomeric antioxidant 1 was prepared by the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with N-[4-(chlorocarbonyl)phenyl]maleimide in the presence of imidazole. Monomeric antioxidant 2, bearing carbamate group, was synthesized from the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and azidomaleimide. Antioxidant 3 was prepared by the reaction of N-(4-hydroxyphenyl)maleimide and 3-(3,5-ditert-butyl-4-hydroxyphenyl) propionic chloride in the presence of triethylamine. These reactive antioxidants were grafted onto polypropylene (PP) by melt-processing with free radical initiators in a mini-max moulder. From the infrared spectra of the grafted PP, it was found that the monomeric antioxidants were grafted onto PP. IR spectroscopic methods were used for the quantitative determination of the extent of grafting of monomeric antioxidant. To optimize the reaction conditions, the influences of the concentration of DCP, monomeric antioxidant, reaction time and temperature on the extent of grafting were studied.

The New Substituent Constants in the Excited States

  • Shim Sang Chul;Park Joon Won;Ham Hie Seok
    • Bulletin of the Korean Chemical Society
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    • 제3권1호
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    • pp.13-18
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    • 1982
  • The new substituent constants $({\sigma}^{\ast})$ are calculated from the acidity constants $(pK^{\ast})$ of phenol derivatives in the excited state ($^1L_b$). These substituent constant are applied to the Hammett equations and found good correlation with $pK^{\ast}$ of 2,6-di-tert-butyl phenol, benzamide, nitroaniline, thiophenol, azobenzene, and benzoic acid derivatives. The correlation was much better than that of ground state substituent constants such as ${\sigma},\;{\sigma}^+$, and ${\sigma}^-$. From these results, the new substituent constants $({\sigma}^{\ast})$are proposed to be used for the linear free energy relationship in the $^1({\pi},{\pi}^{\ast})$ excited states of phenyl compounds.

Activation and immobilization of phenol-degrading bacteria on oil palm residues for enhancing phenols degradation in treated palm oil mill effluent

  • Tosu, Panida;Luepromchai, Ekawan;Suttinun, Oramas
    • Environmental Engineering Research
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    • 제20권2호
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    • pp.141-148
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    • 2015
  • The presence of phenols in treated palm oil mill effluent (POME) is an environmental concern due to their phytotoxicity and antimicrobial activity. In this study, phenol-degrading bacteria, Methylobacterium sp. NP3 and Acinetobacter sp. PK1 were immobilized on oil palm empty fruit bunches (EFBs) for removal of phenols in the treated POME. The bacterial exopolysaccharides (EPS) were responsible for cell adhesion to the EFBs during the immobilization process. These immobilized bacteria could effectively remove up to 5,000 mg/L phenol in a carbon free mineral medium (CFMM) with a greater degradation efficiency and rate than that with suspended bacteria. To increase the efficiency of the immobilized bacteria, three approaches, namely activation, acclimation, and combined activation and acclimation were applied. The most convenient and efficient strategy was found when the immobilized bacteria were activated in a CFMM containing phenol for 24 h before biotreatment of the treated POME. These activated immobilized bacteria were able to remove about 63.4% of 33 mg/L phenols in the treated POME, while non-activated and/or acclimated immobilized bacteria could degrade only 35.0%. The activated immobilized bacteria could be effectively reused for at least ten application cycles and stored for 4 weeks at $4^{\circ}C$ with the similar activities. In addition, the utilization of the abundant EFBs gives value-added to the palm oil mill wastes and is environmentally friendly thus making it is attractive for practical application.

Antioxidant activities of brown teff hydrolysates produced by protease treatment

  • Yun, Ye-Rang;Park, Sung-Hee
    • Journal of Nutrition and Health
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    • 제51권6호
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    • pp.599-606
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    • 2018
  • Purpose: Various plants, herbal medicines, and marine foodstuffs have been used in kimchi preparation to improve its overall quality. Teff, which is rich in minerals and starches, facilitates stable blood glucose levels and is well-suited for use in gluten-free products; hence, it can be used to reinforce the mineral composition of kimchi. In this study, we probed the antioxidant activities of hydrolysates prepared by treatment of brown teff with three proteases under different conditions. Methods: The mineral composition of brown teff was determined by inductively coupled plasma spectrophotometry-mass spectrometry, and we established optimal hydrolysis conditions by determining the total phenol and flavonoid contents of teff hydrolysates obtained using three different proteases (protamax, flavourzyme, and alcalase), two different protease concentrations (1 and 3 wt%), and three different incubation times (1, 2, and 4 h). The antioxidant activity of the hydrolysates was further investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, total antioxidant capacity (TAC), and ferrous reducing antioxidant power (FRAP) assays. Results: Brown teff was rich in I, K, Mg, and Ca, and the highest total phenol content ($24.16{\mu}g/mL$), total flavonoid content ($69.08{\mu}g/mL$), and TAC were obtained for 1 wt% protamax treatment. However, the highest DPPH scavenging activity and FRAP values were observed for hydrolysates produced by alcalase and flavourzyme treatments, respectively. Conclusion: Treatment of brown teff with proteases affords hydrolysates with significantly increased antioxidant activities and high total phenol and flavonoid contents, and these antioxidant activities of teff hydrolysates have the potential to enhance the quality and functionality of kimchi in future applications.

아크릴계 페놀수지 합성과 이를 이용한 도료의 물성연구 (A Study on the Synthesis of Acrylic Phenol Resins and Their Properties as a Paint)

  • 황수인;김영진;김동권
    • 공업화학
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    • 제24권2호
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    • pp.171-176
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    • 2013
  • 지구온난화 문제가 대두되면서 volatile organic compound (VOC) free 도료의 필요성이 크게 증가하고 있다. 현재 국내외적으로 사용되고 있는 도료의 약 70~80% 정도가 용매형 도료이다. 따라서 지구온난화 문제의 근본적인 해결을 위해서는 도료의 희석제로 사용되고 있는 용매인 휘발성 유기화합물(VOCs)의 배출을 최소화 할 수 있는 무용제형도료의 개발이 필수적이다. 본 연구에서는 무용제도료를 개발하기 위하여 기존의 페놀수지의 특성인 산성화로 인해 도료로 사용 시 부착성이 떨어지는 단점을 보완하기 위해 아크릴계 단량체들을 첨가하였다. 합성한 페놀수지와 PF/PMMA 블렌드 수지와 PF/PHEMA 블렌드 수지의 구조분석결과 블렌드된 형태를 확인하였고 접착인장강도실험을 통해 PF/PMMA 블렌드 수지가 2.818 Mpa의 값으로 도료시스템에 적용 가능성을 확인하였다.

Comparative phenolic compound profiles and antioxidative activity of the fruit, leaves, and roots of Korean ginseng (Panax ginseng Meyer) according to cultivation years

  • Chung, Ill-Min;Lim, Ju-Jin;Ahn, Mun-Seob;Jeong, Haet-Nim;An, Tae-Jin;Kim, Seung-Hyun
    • Journal of Ginseng Research
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    • 제40권1호
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    • pp.68-75
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    • 2016
  • Background: The study of phenolic compounds profiles and antioxidative activity in ginseng fruit, leaves, and roots with respect to cultivation years, and has been little reported to date. Hence, this study examined the phenolic compounds profiles and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activities in the fruit, leaves, and roots of Korean ginseng (Panax ginseng Meyer) as a function of cultivation year. Methods: Profiling of 23 phenolic compounds in ginseng fruit, leaves, and roots was investigated using ultra-high performance liquid chromatography with the external calibration method. Antioxidative activity of ginseng fruit, leaves, and roots were evaluated using the method of DPPH free-radical-scavenging activity. Results: The total phenol content in ginseng fruit and leaves was higher than in ginseng roots (p < 0.05), and the phenol content in the ginseng samples was significantly correlated to the DPPH free-radical-scavenging activity ($r=0.928^{****}$). In particular, p-coumaric acid ($r=0.847^{****}$) and ferulic acid ($r=0.742^{****}$) greatly affected the DPPH activity. Among the 23 phenolic compounds studied, phenolic acids were more abundant in ginseng fruit, leaves, and roots than the flavonoids and other compounds (p < 0.05). In particular, chlorogenic acid, gentisic acid, p- and m-coumaric acid, and rutin were the major phenolic compounds in 3e6-yr-old ginseng fruit, leaves, and roots. Conclusion: This study provides basic information about the antioxidative activity and phenolic compounds profiles in fruit, leaves, and roots of Korean ginseng with cultivation years. This information is potentially useful to ginseng growers and industries involved in the production of high-quality and nutritional ginseng products.

친환경 토마토 농축액을 이용한 토마토 와인과 시중 판매 와인 품질 모니터링 (Monitoring of Wine Quality by using Environmentally friendly Tomato Concentrate and Commercial Wines)

  • 이슬;문혜경;이수원;문재남;김동환;김귀영
    • 한국식생활문화학회지
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    • 제29권3호
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    • pp.278-285
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    • 2014
  • This study investigated the quality characteristics of fermented wines using a selected strain to obtain basic data on sugar-free tomato wine production. Alcohol content of the tomato and commercial wine was 8.2~12.9%, whereas tomato wine showed a relatively low alcohol content of 8.2%. For total phenol content, Chile wine showed the highest value of 162.89 mg/100 g, followed by persimmon wine at 122.33 mg/100 g. Tomato wine showed a relatively high total phenol content of 96.57 mg/100 g. In all sections, xylose was not detected, although there were differences in free sugars depending on each product. Acetic and citric acid contents were highest in tomato wine, and the six kinds of commercial wine and tomato wine showed acetic acid content of 800.6 mg/100 g and citric acid content of 1,064.4 mg/100 g. The total free amino acid content was 100.63 mg/100 g in tomato wine, which was 2~3 times higher compared to that in commercial wine ($26.33{\pm}52.15mg/100g$).

Free radical scavenging property of Annona reticulata leaves

  • Mondal, Susanta Kumar;Saha, Prerona;Mondal, NB;Mazumder, UK
    • Advances in Traditional Medicine
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    • 제8권3호
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    • pp.260-265
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    • 2008
  • Annona reticulata belonging to the family Annonaceae is traditionally used as anthelmintic and it is reported to have anticancer activity. Free radicals are known to be involved in various types of diseases like cancer, diabetes, neurological disorders etc. The present study was aimed to evaluate free radical scavenging property of methanol extract of the leaves of Annona reticulata in some in vitro models e.g. DPPH, nitric oxide, superoxide and lipid peroxide radical model. The extract showed good dose-dependent free radical scavenging property in all the models. $IC_{50}$ values were found to be 3.22, 170.01, 25.12 and $140.12\;{\mu}g/ml$ respectively in DPPH, nitric oxide, superoxide and lipid peroxidation inhibition assays. Reductive ability of the extract was also tested based on potassium ferricyanide reduction where dose dependant reducing capability was observed. Measurement of total phenolic compounds by Folin-Ciocalteu's phenol reagent indicated that 1mg of the extract contained $146.20\;{\mu}g$ equivalent of pyrocatechol. The findings ascertain promising free radical scavenging property of the extract and the antioxidant property of the extract may be due to the high content of phenolic compounds.

헛개나무(Hovenia dulcis THUNBER var. koreana Nakai) 추출물의 항산화효과

  • 이윤아;문혜연
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.307-312
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    • 2003
  • 헛개나무를 부위별 추출하여 total polyphenol과 flavonoid, Vitamin C equivalent antioxidant capacity를 연구한 결과 헛개나무의 수피와 열매에서 가장 많이 조사되었고 DPPH free radical scavenging activity에서도 수피와 열매에서 활성이 뛰어났다. 식물 추출물인 Polyphenol성 물질이 많이 존재 할 수록 항산화 활성은 뛰어났다.

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