• Title/Summary/Keyword: Phenolic

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Antioxidant Activity and Total Phenolic Content of Triphala churna

  • Jayajothi, E.;Elavarasu, T.;Hamsaveni, M.;Sridhar, S.K.
    • Natural Product Sciences
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    • v.10 no.1
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    • pp.16-19
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    • 2004
  • Triphala churna is a widely used herbal formulation that contains equal proportion of dried fruit powder of Emblica officinalis, Terminalia chebula and Terminalia belirica. In the Indian system of medicine, it is used in cleaning wounds, urinary disorders, diabetes mellitus, leprosy, constipation, eyesight promotion, piles, and as a rejuvenator. In the present study, the methanolic extract of 5 commercial Triphala was evaluated for antioxidant activity by 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging method, total phenolic content by Folin-Ciocalteu method and gallic acid equivalents (GAE) by high performance thin layer chromatographic (HPTLC) method. All extracts exhibited antioxidant activity significantly. The $IC_{50}$ of the extracts ranged between $7.16\;to\;12.96\;{\mu}g/ml$. The total phenolic content of the extracts was found to be 195.3-296.4 mg of GAE/gm of GAE/gm dw. The HPTLC chromatographic data reveal that the content of GAE present in the extract was found to be $7.17-4.11\;{\mu}g/ml$. The study reveals that out of the churnas analysed, C was found to exhibit the most potent antioxidant activity. A clear correlation between $IC_{50}$ and content of GAE nor the total phenolic content could be observed. The study reveals that the consumption of Triphala would exert several beneficial effects by virtue of its antioxidant activity.

Antioxidant Activity and Total Phenolic Content of Callistemon citrinus Extracts

  • Park, Young-Ki;Lee, Wi-Young;Park, So-Young;Ahn, Jin-Kwon;Han, Mu-Seok
    • Food Science and Biotechnology
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    • v.14 no.2
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    • pp.212-215
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    • 2005
  • Ethanol crude extracts of wood, bark, leaf, and fruit of Callistenwn citrinus were compared for their antioxidant activities based on DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and reducing power. Bark extract showed the most potent radical-scavenging activity and reducing power, showing 94.1 and 0.64% at 25 and $100\;{\mu}g/mL$, respectively. Total phenolic content of the bark extracts (275.0 mg GAE/g) was higher than those of others. Further fractionation of the bark extract using hexane, $CH_2Cl_2$, and EtOAc showed EtOAc fraction had the highest antioxidant activity ($IC_{50}\;6.7\;{\mu}g/mL$) and reducing power (0.82 at $100\;{\mu}g/mL$), with total phenolic content of 611.1 mg GAE/g. Total phenolic contents correlated with antioxidant activity ($R^2\;=\;0.7061$) and reducing power ($R^2\;=\;0.7399$).

Preparation and Characterization of Phenolic/Furfural Organic Gel Microspheres in Supercritical $CO_2$ (초임계 이산화탄소를 이용한 Phenolic/Furfural계 유기 겔 입자의 합성 및 물성)

  • 이경남;이해준;김중현
    • Polymer(Korea)
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    • v.24 no.1
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    • pp.8-15
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    • 2000
  • Phenolic/furfural(P/F) gel microspheres were successfully produced by new supercritical $CO_2$-based process. $CO_2$-soluble poly(dimethylsiloxane) (PDMS) was used as the stabilizer in this system. Spherical morphology of the gel microspheres was confirmed by scanning electron microscopy. Particle size and particle size distribution of P/F gel microspheres can be modified by variety of the solids content and the stabilizer content. The resultant P/F gel microspheres have average particle size in the range of 1-6 ${\mu}{\textrm}{m}$. The structure of P/F gel microspheres was revealed by thermogravimetric analysis and IR analysis.

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Total Phenolic Contents and Biological Activities of Korean Seaweed Extracts

  • Kim, So-Jung;Woo, Seon-Ock;Yun, Hee-Young;Yum, Seung-Shic;Choi, Eun-Seok;Do, Jeong-Ryong;Jo, Jin-Ho;Kim, Dong-Giun;Lee, Suk-Chan;Lee, Taek-Kyun
    • Food Science and Biotechnology
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    • v.14 no.6
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    • pp.798-802
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    • 2005
  • Crude extracts of thirty seaweeds collected in Korea were obtained using 50% ethanol, and total phenolic contents and antioxidant activities were compared. Two brown algae, Ecklonia cava (E. cava) and Sargassum siliquastrum (S. siliquastrum), showing high antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide anion radical scavenging activity were further investigated for their inhibitory effects on tyrosinase activity. The E. cava extract had the highest total phenolic content among the seaweeds extracts. Total phenolic contents were strongly correlated with antioxidant activity in the thirty seaweed extracts ($R^2\;=\;0.9169$). The E. cava and S. siliquastrum extracts exhibited higher inhibition to tyrosinase activity than butylated hydroxytoluene (BHT) and epigallocatechin gallate (EGCG).

Effects of Roasting and Peeling Process and Extraction Temperature on the Antioxidant Activity of Burdock Tea (우엉차의 껍질 제거와 로스팅에 따른 추출온도별 항산화 효과)

  • Park, Mi Young;Yu, Chengguang;Park, Young Hyun
    • Korean Journal of Medicinal Crop Science
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    • v.24 no.5
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    • pp.351-359
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    • 2016
  • Background: We investigated the optimal aqueous extraction conditions for recovery of high yields of total phenolic compounds from roots of Arctium lappa L. (burdock, Asteraceae), and we compared their antioxidant capacity. Methods and Results: The antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt, and oxygen radical absorbance capacity assays. In addition, the major phenolic compounds present in the extracts were determined by high performance liquid chromatography analysis. Our results suggest that the roasted burdock $100^{\circ}C$, 15 min extract exhibited the strongest radical scavenging activity and possessed the highest concentration of phenolic compounds. The polyphenol content of both dried burdock and roasted burdock significantly increased with increase in the extraction temperature and time. Conclusions: These results indicated a relationship between phenolic compound levels in burdock and their free radical scavenging activities. This suggests that phenolic compounds significantly increase the antioxidant potential of burdock extracts.

Carbonization Characteristics of Phenolic Resin Deteriorated by Tracking (트래킹에 의해 열화된 페놀수지의 탄화 특성)

  • 송길목;최충석;노영수;곽희로
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.1
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    • pp.1-7
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    • 2004
  • This paper describes the carbonization characteristics of a phenolic resin deteriorated by tracking under the environment of a fire. In the experiment, a liquids droplet of 1[%] NaCl was dripped on the phenolic resin to cause a tracking with 110[V], 220[V] voltages applied. It can be addressed from the experimental results that when an insulator is carbonized by an external fire, its structure is amorphous. If an insulator is carbonized by electrical cause, on the other hand, its structure would be crystalline. In order to observe the surface change of the phenolic resin, the tracking process was analyzed by using SEM. In the case that the materials are carbonized under heat or fire, the exothermic peak appears around 500[$^{\circ}C$]. This is one of the important factors to determine the cause of fires. As a result of DTA, the exothermic peaks of an untreated sample showed at 333.4[$^{\circ}C$], 495.7[$^{\circ}C$] but those of a sample deteriorated by tracking appeared at 430.6[$^{\circ}C$], 457.6[$^{\circ}C$] in a voltage of 110[V], and at 456.2[$^{\circ}C$], 619.7[$^{\circ}C$] in a voltage of 220[V]. It is possible, therefore, to distinguish a virgin sample from carbonized samples(graphite) by the exothermic peak.

Investigation of Cure Kinetics and Storage Stability of the o-Cresol Novolac Epoxy Nanocomposites with Pre-intercalated Phenolic Hardeners

  • Hwang, Tae-Yong;Lee, Jae-Wook;Lee, Sang-Min;Nam, Gi-Joon
    • Macromolecular Research
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    • v.17 no.2
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    • pp.121-127
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    • 2009
  • The cure kinetics of the epoxy-layered, silicate nanocomposites were studied by differential scanning calorimetry under isothermal and dynamic conditions. The materials used in this study were o-cresol novolac epoxy resin and phenol novolac hardener, with organically modified layered silicates. Various kinetic parameters, including the reaction order, activation energy, and kinetic rate constants, were investigated, and the storage stability of the epoxy-layered silicate nanocomposites was measured. To synthesize the epoxy-layered silicate nanocomposites, the phenolic hardener underwent pre-intercalation by layered silicate. From the cure kinetics analyses, the organically modified layered silicate decreased the activation energy during cure reaction in the epoxy/phenolic hardener system. In addition, the storage stability of the nanocomposite with the pre-intercalated phenolic hardener was significantly increased compared to that of the nanocomposite with direct mixing of epoxy, phenolic hardener, and layered silicate. This was due to the protective effect of the reaction between onium ions and epoxide groups.

Antioxidant Activities of Methanol Extracts and Phenolic Compounds in Asian Pear at Different Stages of Maturity

  • Zhang, Xian;Koo, Ja-Heon;Eun, Jong-Bang
    • Food Science and Biotechnology
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    • v.15 no.1
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    • pp.44-50
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    • 2006
  • Contents of phenolic compounds in peel, flesh, and core of three Asian pear cultivars, Hosui, Niitaka, and Chuwhangbae, were determined at different stages of maturity. Antioxidant properties of methanol extracts of peels at various fruit maturity stages were also evaluated. Total phenolic content decreased with maturity. Arbutin, chlorogenic acid, and epicatechin were major phenolic compounds in young fruits. Catechin, 4-hydroxymethyl benzoic acid, and caffeic acid were detected in peel and core of immature and mature pears. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of methanol extracts were 16.30 and $15.73\;{\mu}g$ in peel of immature Hosui and Chuwhangbae pears, respectively, and $11.59\;{\mu}g$ in mature Niitaka pears, which was significantly higher than those of other maturity stage in the same cultivar. Inhibitory activities on lipid oxidation of methanol extracts of three cultivars at all maturity stages were similar to that of ${\alpha}$-tocopherol.

Experimental analysis of pultrusion process for phenolic foam composites (발포 복합재료 Pultrusion 공정의 실험적 해석)

  • Lee WooIl;Yun MyungSeok
    • Composites Research
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    • v.18 no.3
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    • pp.47-52
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    • 2005
  • Pultrusion process of phenolic foam composite is investigated. Phenolic foam composites provide heat and flame resistance with less weight. When made into foam, a variety of properties can be obtained with different bubble size and number density. In this study, effect of process variables on the foaming characteristics of phenolic resin composites during pultrusion process has been studied experimentally. The process variables considered are the heating temperature and the pulling speed as well as the mass fraction of blowing agent. Experiments were performed using a laboratory scale pultrusion apparatus. Optimal process condition was found by observing the micro-morphology.

Phenolic Compounds Production, Enhancement and Its Antioxidant Activity of Blue Berry Powder with Bacillus subtilis Light Mediated Fermentation Compounds

  • Elumalai, Punniyakotti;Lim, Jeong-Muk;Mohan, Harshavardhan;Lee, Jeong-Ho;Oh, Byung-Taek
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.04a
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    • pp.66-66
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    • 2018
  • Light fermentation has been conducted under different light conditions such as normal dark light, white light, and light emitting diodes (LEDs) various color (blue, green, red, white on blueberry powder with fermenting bacteria Bacillus subtilis (B2). The bacteria B2 was isolated and identified by 16S rRNA sequencing method. RYRP biologically converted to secondary metabolites through light fermentation in the presence of Bacillus subtilis, the bacteria actively involved in bioconversion process. LEDs fermentation to enhance the production of phenolic content while comparing to normal dark and white light. Among the different color LEDs, blue LEDs mediated fermentation showed higher amount of total phenolic and flavonoid content. Then blue LEDs mediated fermented compound were characterized by FTIR and GC-MS, subsequently the compound was analyzed antioxidant activity tests and the antioxidant activity exhibited higher. This is the first study to demonstrate that B. subtilis-LEDs mediated fermentation is useful for facilitating phenolic compound production and enhancing antioxidant activity, which may have greater application fermentation fields.

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