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        검색결과 23

        1.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Integration of noble metals on graphene is renowned for their catalytic and antioxidant prowess. However, utilization of toxic chemicals in the synthesis creates environmental pollution and poisonous nature of chemically synthesized materials. To address this, an economical and eco-friendly method for synthesizing graphene-gold (BRG-Au) nanocomposite by anchoring gold nanoparticles (Au NPs) onto reduced graphene oxide sheets using betel leaf extract as a reducing and stabilizing agent is presented. Comprehensive structural characterizations through UV–Visible, Raman, FT-IR, and XRD analyses confirm the successful formation of the BRG-Au nanocomposite. Morphological assessments utilizing FE-SEM and TEM techniques revealed the presence of transparent, twinkling graphene sheets embellished with 20 to 60 nm of Au NPs in various shapes, including spherical, triangular, pentagonal, circular, and trapezoids. The catalytic and antioxidant activities of the BRG-Au nanocomposite were thoroughly evaluated. In catalytic trials, the nanocomposite exhibited remarkable efficiency in the reduction of 4-nitrophenol to 4-aminophenol, accomplishing this transformation within a mere 30 min during the initial cycle and maintaining stable catalytic performance over three consecutive cycles. Additionally, antioxidant analyses employing Total Antioxidant Activity and 2,2-diphenyl-1-picrylhydrazyl methods demonstrated that BRG-Au nanocomposite possessed equal or superior antioxidant activity than the ascorbic acid standard. This research thus underscores the promising potential of environmentally benign synthesis method for graphene-gold nanocomposite with enhanced catalytic and antioxidant properties.
        4,300원
        3.
        2017.10 구독 인증기관·개인회원 무료
        Honey production from approximately 1.7 million colonies owned by around 21 thousand beekeepers was almost 36 thousand M/T in Korea. Pollen has used as a food and medicine from before the Joseon Dynasty period in Korea. Pollen grains such as acorn (Quercus acutissima), actinidia (Actinidia arguta) and green tea (Camellia sinensis) are popular in the markets in Korea. But stiff pollen wall hindered dissolution of polysaccharides and lowered extraction efficiency. In the present study, we measured the antioxidant activity and the total polyphenol content from the pulverized and lyophilized green tea pollen grains inoculated with 6 kinds of fungi to confirm the husk removal effect. The total polyphenol content of green tea pollens was highest in lyophilized pollen medium inoculated with Armillaria mellea, and was lowest in pollen inoculated with Lentinula edodes. Total polyphenol content of the lyophilized pollen was higher than that of the refined pollen and the pulverized pollen in green tea pollen germinated with A. mellea. The total polyphenol content of the lyophilized green tea pollens germinated with A. mellea was 1.4-fold higher than that extracted with water. Measurement of antioxidant activity using the DPPH free radical scavenging method showed that the lyophilized green tea pollen grains germinated with A. mellea had the highest and that germinated with L. edodes was lowest in antioxidant activities. The lyophilized green tea pollen grains germinated with A. mellea was 2 to 4 times higher than that extracted with water in the antioxidant activity of DPPH free radical scavenging. Many germinated cells were formed around pore of green tea pollen inoculated with L. edodes, while those were formed at the end of hyphae derived from green tea pollen grains inoculated with A. mellea.
        4.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To enhance the physiological activities of roasted coffee (RC), 30 kinds of green coffee beans (GCB) with different cultivating areas and varieties were fermented with Monascus ruber mycelium (MR) by solid-state culture. After the dried MR-fermented GCB was subjected medium roasting, each RC was extracted with hot-water. Among the hot-water extracts, the highest yield was the hot-water extract of RC from MR-fermented Indonesia Mandheling GCB (15.5%). However, the hot-water extract of RC from MR-fermented Ethiopia Sidamo GCB showed significantly higher polyphenolic contents (3.08 mg GAE/100 mg) and ABTS free radical scavenging activity (25.41 mg AEAC/100 mg). Meanwhile, the hot-water extract of RC from MR-fermented Vietnam Robusta GCB showed not only the effective inhibition of TNF-α level (73.7% inhibition of LPS-stimulated control) from LPS-stimulated RAW 264.7 cells but also significant inhibition of lipogenesis (63.5% inhibition of lipid differentiation control) in 3T3-L1 pre-adipose cells. In conclusion, these results suggest that roasted coffees from Ethiopia Sidamo and Vietnam Robusta green coffee beans fermented with Monascus ruber mycelium using solid-state culture could have industrial applications as functional coffee beverages.
        4,200원
        5.
        2010.10 구독 인증기관·개인회원 무료
        Pyrifluquinazon, as a quinazinalone chemical group, based on a new mode of biological activity. It is reported that mode of action is modifies insect behavior, rapidly stopping feeding such that insects starve to death. Time-release feature and mortality effect on M. persicae using different pyrifluquinazon nano type and non-nano type were compared. Pyrifluquinazon nano type was formulated with different molecular weight and density of used chitosan (CS 30000 0.1% and CS 3000 0.3%). In the CS 30,000 0.1%, the mortality was weakly occurred at early time, but steadily increased after 4days. Finally, we confirmed more than 70% mortality as a peak at 16days. In CS 3000 0.3%, the mortality showed about 70% until 18days as a effective controlled release. Also, We examine time-release feature and mortality effect on M. persicae according to the different pyrifluquinazon nano type(CS 30000 0.1% and CS 3000 0.3%) of concentrations. The CS 30000 0.1% bioassay results of different concentration were showed that the highest concentration(100ppm) was measured better mortality than other concentration at 0 day, but cannot confirm different effect about dissimilar concentration. However, increasing rates of M. persicae were low as treatment concentrate was high. In CS 3000 0.3% 100ppm concentration bioassay result, aphid mortality reached peak at 24 days and increasing rate also low. Additionally, for the comparing of bioassay and feeding behavior of M. persicae against pyrifluquinazon nano types and non-nano type, EPG technique was carried out. In case of non nano type, feeding inhibition efficacy was showed during 4 days after treatment, but appeared similar level with control after 10days. In CS 3000 0.3% 50ppm, residual efficacy was specially showed until 28days after treatment whereas treatments with CS 30000 0.1% were similar to the control after 22days. These result show that the change of feedinng behavior and motrality of M. persicae is correlated with the change of nano type or non nano type of pyrifluquinazon.
        7.
        1993.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        포장의 약제저항성 변동요인을 조사하기 위하여 복수아혹진딧물의 Carboxyl esterase(CE) 활서측정에 의한 저항성도의 변동상황을 조사하였다. 비닐하우스에서 고추육묘중 발생한 복수아혹진딧물의 CE활성 측정 결과 약제저항성도는 무처리구가 40이였으나 아세페이트를 처리한구는 78로 약제처리로 인한 저항성도가 38이 증가하였다. 또한 노천망실에서 약제처리를 하지 않고 재배한 케일에 발생한 복숭아혹진딧물의 CE활성에 의한 저항성도는 7월이 24이었으나, 8, 9월의 활성이 계속 증가하여 10월이 83으로서 최고에 달하였다가 11월에는 다시 81에서 79로 약천 떨어지고 있어 약제이외에 저항성도의 자연변동요인이 있음을 확인하였다. 전국적으로 18개장소에서 채집한 진딧물의 CE활성을 측정한 결과 저항성도의 평균이 여름은 5014였으며 늦가을인 11월은 8210으로서 여름보다 늦가을인 11월이 32가 높았으며 그중에도 약제를 살포사지 않은 곳 보다 약제살포 회수가 많은 곳일수록 높았다.
        4,000원
        8.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        The green synthesis of inorganic nanoparticles (NPs) using biomaterials has garnered considerable attention in recent years because of its eco-friendly, non-toxic, simple, and low-cost nature. In this study, we synthesized NPs of noble metals, such as Ag and Au using an aqueous extract of a marine seaweed, Ecklonia cava. The formation of AgNPs and AuNPs was confirmed by the presence of surface plasmon resonance peaks in UV-Vis absorption spectra at approximately 430 and 530 nm, respectively. Various properties of the NPs were evaluated using characterization techniques, such as dynamic light scattering, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. Phytochemicals in the seaweed extract, such as phlorotannins, acted as both reducing and stabilizing agents for the growth of the NPs. The green-synthesized AgNPs and AuNPs were found to exhibit high catalytic activity for the decomposition of organic dyes, including azo dyes, methylene blue, rhodamine B, and methyl orange.
        9.
        2018.10 서비스 종료(열람 제한)
        Background : For the green approach of nanoparticles synthesizing, plant based technology has been considered as cost-effective and eco-friendly mass production. The oriental medicinal crop, Kalopanax septemlobus (Thunb.) Koidz. (Korean name: 음나무), the deciduous tree and a family of Araliaceae. Endemic tree of Asian countries, K. septemlobus being used for the treatment of various diseases. Phytochemicals of K. septemlobus such as polyphenols has highly probability of reducing agent for biosynthesizing nanoparticles. Methods and Results : In this study, we applied K. septemlobus ZnO nanoparticles (Ks-ZnO NPs) with procedures including green approach one-pot synthesis. For the characterization of nanoparticles, UV–Vis, FTIR, XRD, SEM and TEM were used. The formation of ZnO nanoparticles, the aurface plasmon resonance were observed at 372 ㎚ in UV-Vis spectroscopy. The presence of functional groups which as a capping agent and formation of ZnO nanoparticles were confirmed in FTIR result. The crystallization and morphology showed by XRD, TEM and SEM respectively. The photocatalytic activity of ZnO nanoparticles, was determined using Methylene blue (MB) dye degradation under UV irradiation (365 ㎚) which resulted rate constant is (−k) 0.1215 with 97.5% of degradation in 30 min. Conclusion : The result shows that phytochemicals in K. septemlobus extract have a potential as a reducing agent to form ZnO nanoparticles. The ZnO NPs are capable to degrade MB with in brief time.
        10.
        2018.10 서비스 종료(열람 제한)
        Background : Panos extract is a mixture of four Panax plant extracts namely Dendropanax morbifera, Panax ginseng, Acanthopanax senticosus and Kalopanax septemlobus. We intended to use Panos extract for ZnO nanoparticles(NPs) synthesis and application for waste water treatment. Methods and Results : In the present study, we have synthesized Panos ZnO nanoparticles via co precipitation method. Characterization of the NPs has been done using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and UV-Visible spectroscopy. An average of 75% efficacy in degrading the methylene blue dye has been observed. The nanoparticles showed antibacterial activity against E. coli and S. aureus. Conclusion : The results shows that Panos ZnO NPs can be a potential eco-friendly and economical tool for waste water management in the current scenario where there an intense urge to remediate the polluted environment through novel approaches such as Nanobiotechnology.
        11.
        2018.10 서비스 종료(열람 제한)
        Background : Codonopsis lanceolata is a perennial herb called as ‘Deodeok’ (더덕) in Korea. The roots of C. lanceolate has been reported to have some antioxidant and antimicrobial properties. The chemically reactive saponins of C. lanceolata might be used as a capping agent for the surface of ZnO nanoparticle, ultimately making it a highly efficient photocatalyst. Methods and Results : In this paper, we report the one-pot green synthesis of ZnO nanoparticles via precipitation method using root extract of C. lanceolata. The structure of green synthesized Cl-ZnO NPs was characterized using XRD, EDX, DLS and morphology using TEM. The FT-IR exhibited the information about the functional groups that capped the metal nanoparticle and the formation of metal NPs was confirmed by UV–vis spectra at 356nm. The Cl-ZnO NPs were evaluated for their catalytic activity by measuring the degradation of methylene blue (MB) dye in aqueous solution under UV light (365 ㎚). The result showed efficient degradation of MB, which was degraded 70% within 30 min by Cl-ZnO NPs. Conclusion : This study proves that the green route synthesized ZnO NPs from the root extract of C. lanceolata are low cost, time efficient, bio-degradable and non- toxic. The UVvis spectra confirmed the synthesis of ZnO NPs from C. lanceolata root extract. The Cl- ZnO NPs mediated catalysis exhibited high photocatalysis rate in short time. Ultimately, the green rapid synthesized Cl-ZnO NPs from root extract can be used as an efficient
        12.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        Hericium erinaceus is considered a functional food and potential medicinal source. The present study was conducted to examine the potential antioxidant and anti-inflammatory activities of carried out with water and ethanol extracts of Hericium erinaceus grown on germinated green rice (HEGR-W and HEGR-E, respectively) and the water and ethanol extracts of germinated green rice (GR-W and GR-E, respectively) as potential medicinal resources or antioxidant and anti-inflammatory agents. Methods and Results: The total phenolic and flavonoid contents, DPPH, and ABTS activity, reducing power, DNA protective activity, cell viability, and NO production were investigated. The total phenolic and flavonoid contents were highest in HEGR-E (66.53 ± 2.40 ㎎·GAE/100 g and 82.12 ± 7.10 ㎎·CE/100 g respectively). HEGR-E exhibited high DPPH (44.70 ± 1.28%) and, ABTS (44.70 ± 1.28%) activity and reducing power (0.219). HEGR and GR extracts showed protective activity against DNA damage. The cytotoxicity of HEGR and GR in RAW264.7 cells and LPS-induced RAW264.7 cells was low. HEGR-E and GR-W exhibited anti-inflammatory effects through a 28% inhibition of NO production in LPS-induced RAW264.7 cells. Conclusions: These results suggested that the extracts of Hericium erinaceus grown on germinated green rice could be a potential medicinal material with natural antioxidant and NO inhibitory properties.
        13.
        2017.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        With the goal of developing a new functional fermentation milk using green tea powder (GP), milk was fermented with direct vat set (DVS) starter culture containing Streptococcus salivarius subsp. thermophilus, Lactobacillus paracasei and L. delbrueckii subsp. bulgaricus. We investigated fermentation characteristics and antioxidative activities of fermented milk supplemented with different concentrations (0.5, 1, 2, 3%) of GP. All samples were evaluated for pH, total acidity, viable cell count, and sugar contents. The pH of all samples decreased during fermentation, and the final pH ranged from 4.35 to 4.51. The acidity increased during fermentation, after the fermentation was completed, the titratable acidity was 0.8 to 1.1%. And viable cell count of all samples increased during fermentation, and the final viable cell count was 8.57 to 8.89 log CFU/mL. The sugar content decreased as the fermentation proceeded and finally reached 12 to 13 ˚Brix. And increasing GP, decreased brightness and increased yellowness. Increasing GP concentration added to milk, improved DPPH free radical scavenging activity and ferric ion reducing activity of fermentation milk. The fermentation milk kept their pH, total acidity and viable cell counts standard of fermentation milk during the storage period at 4℃. These findings confirmed the possibility of development of the novel functional fermentation milk through the investigation of the quality characteristics of the fermentation milk added with GP.
        14.
        2016.10 서비스 종료(열람 제한)
        Background : Invitro antioxidant activity, polyphenol and flavonoid aglycone contents in black and green tea products of balloon flower leaves were investigated to provide valuable information for the further development and utilization of resources of Platycodon grandiflorum. Methods and Results : Flavonoid aglycone contents were investigated using HPLC (SHIMADZU, Japan) with a hypersil ODS column (125 mm × 4 mm, 5-μm particle, HP). DPPH and ABTS radical scavenging activities were measured by method of Lee & Lee (2004) with slight modification. Antioxidant activity, polyphenol and flavonoid contents in green tea were significantly higher than these in black tea. PC analysis indicated that first principal components explained 79.9% of the total variability for five traits investigated. PC2 explained 19.7% of the variation. Conclusion : It can be concluded from these results that these characteristics can reveal the active compound variation of black and green tea products of balloon flower leaves. These results provide scientific evidence for the utilization of balloon flower leaves.
        15.
        2016.10 서비스 종료(열람 제한)
        Background : Plants are the rich source of antioxidants, which plays a very important role in maintaining human health. Their antioxidant property protects cells of different organs of human beings against free radicals and free radical mediated diseases. Even though, there is lack of knowledge on the antioxidant effect of lutein present in plants. In the present study, lutein was isolated from the GreenTea leaves (Camellia sinensis) which is used as a dietary source. Methods and Results : The procedure adopted for the isolation and purification of lutein using acetone extraction and preparative high performance liquid chromatography (HPLC) is simple and less time consuming. Free radicals scavenging activity of isolated lutein from acetone extract of GreenTea was assessed by DPPH radical scavenging assay and reducing power. The isolated lutein scavenged 79% of DPPH radicals at 20 ㎍/㎖ and two fold lower concentration compared to the standard antioxidants (α-tocopherol). No significant differences were found between the reducing power of the lutein and BHT when their concentrations were high. However, significant differences were observed at relatively low concentrations, the reducing power of lutein was isolated from the GreenTea leaves was stronger than those of their acetone extract and standard antioxidants (BHA). Both electron spin resonance (ESR) and in vitro assay confirmed that lutein was isolated from the GreenTea leaves, exhibited a greater capacity for scavenging superoxide (O2 •-) and hydroxyl (OH •) radicals than standard antioxidants β-carotene and α-tocopherol respectively. Conclusion : The results proven that lutein isolated from GreenTea leaves has an efficient antioxidant ability, it could serve as an antioxidant to scavenge reactive oxygen species.
        16.
        2015.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        유기 및 일반재배에 따른 풋고추의 이화학적 품질특성 및 항산화활성을 비교하고자 무게, 길이, 수분함량, 표면색도, 경도, DPPH 및 ABTS radical 소거능, 총페놀함량 등을 분석하였다. 무게, 길이의 경우 전반적으로 유기농 풋고추에서 무게가 적고, 길이가 짧았으며 수분함량의 경우 유기 및 일반재배 간 비슷한 값을 나타내었다. 표면색에 있어서 유기농 풋고추의 L과 b값이 높았고, a값은 일반재배 풋고추의 값이 높았으며 재배조건에 따른 L, a, b값의 유의적인 차이를 보였다. 항산화활성의 경우 DPPH radical 소거능은 유기농 풋고추가, ABTS radical 소거능은 일반재배 풋고추가 높은 활성을 보였다. 총 페놀 함량은 유기농 풋고추 값이 높았으나 유의적 차이를 보이지 않았다. 본 연구에서는 무게, 길이 등의 외적 품질에 대해서 일반재배 풋고추의 값이 높았고, 항산화활성에 대해서는 전반적으로 유기농 풋고추에서 다소 높은 활성을 보였으나 유기 및 일반재배에 따른 내외적 품질비교를 위해서 더 많은 분석이 추가로 진행되어야 할 필요가 있다고 사료된다.
        17.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        본 연구는 시판되고 있는 10종의 녹비작물로부터 추출한 추출물을 이용하여 감자 더뎅이병균(Streptomyces scabiei)에 대한 항균활성을 검정함으로서 감자 더뎅이병 경감을 위한 녹비작물 선발의 기초자료로 활용하고자 하였다. 10종의 녹비작물에 대하여 hexane, ether, ethylacetate, methanol 및 water로 순차적으로 용매분획을 하였다. 그 결과 DPPH free radical 소거능은 ether, methanol 및 water 추출물에서 소거능이 높게 나타났다. 감자 더뎅이병균(Streptomyces scabiei)에 대한 항균활성은 methanol, ethylacetate, ether 및 water 용매를 이용한 모든 녹비작물 추출물의 0.25 mg/mL 농도에서부터 높은 항균활성을 나타내었다. 특히, methanol 용매를 이용한 하우스솔고 추출물은 감자 더뎅이병균에 대하여 다른 녹비작물 보다 더 높은 항균력을 나타내었다. 이상의 결과들로부터 하우스솔고의 이용은 감자 더뎅이병 경감을 위한 최적의 녹비작물로 생각되었다.
        18.
        2009.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        녹차는 생리활성의 촉진작용뿐아니라 항암, 항산화, 고혈압 억제효과, 체중조절 등 다방면의 약리효과를 보이는 것으로 보고되고 있다. 아울러, 녹차의 항균 및 항진균 작용에 관한 연구결과도 발표되고 있으나, 항균작용 기작에 접근한 기초 연구는 별로 많지 않다. 본 연구는 식품변패미생물에 대한 녹차추출물의 항균작용을 구명하는 기초자료를 획득하는데 그 목적이 있다. 녹차추출물의 항균력을 조사한 결과, 이상의 농도에서 뚜렷한 항균활성을 보였고, 광역의
        19.
        2009.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        3개월간 다른 조건에서 저장한 잎 및 분말녹차의 항산화 활성 변화를 조사하였다. 녹차 추출물은 수분활성도(0.81, 0.69, 0.23)와 온도(, , )를 달리하여 3개월간 저장한 잎 및 분말녹차 시료 1.5 g에 의 탈이온수 100mL를 첨가하여 5분간 추출하여 준비하였다. 항산화 특성은 환원력, DPPH radical 소거활성, FRAP 측정법을 이용하여 조사하였다. 모든 실험에서 분말녹차 추출물이 잎녹차 추출물보다 높은 활성을 나타내었으며
        20.
        2009.04 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서는 국내에서 시판되고 있는 4종류의 차 즉, 녹차, 보이차, 우롱차 및 홍차 열수추출물의 페놀성 화합물, 항산화 및 퇴행성 뇌신경질환 저해활성에 대하여 조사하였다. 시판 차 열수추출물의 총 페놀성 화합물 함량은 이었으며, 녹차, 보이차, 우롱차 및 홍차 열수추출물의 총 플라보놀 함량은 각각 350.96, 254.17, 334.48 및 240.23 mg/100 g이었다. 녹차, 보이차, 우롱차 및 홍차 열수추출물의 총 카테킨 함량은 각각
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