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Hyeon-Suk Ham(함현숙),Se-Yeul Lee(이세열),Dong-Wan Lee(이동완),Jong-Hwan Seong(성종환),Han-Soo Kim(김한수),Dong-Seob Kim(김동섭),Young-Guen Lee(이영근) 한국생명과학회 2012 생명과학회지 Vol.22 No.9
비파 잎의 항산화 활성을 탐색하고 활성물질을 분리하여 규명하기 위하여, 동결 건조한 비파 잎을 마쇄하여 n-hexane, ethyl acetate (EtOAc)와 methanol (MeOH)로 용매 분획하였다. 각 추출물에 대하여 정량적으로 DPPH 소거활성, SOD 유사활성을 측정하고, 페놀 화합물과 플라보노이드 함량을 측정하였으며, 각 용매에 따른 추출물 중 비교적 활성이 강한 EtOAc 추출물과 MeOH 추출물에 대하여 column chromatography를 이용하여 얻은 분획물들 중 강한 활성을 보인 각 1개의 분획물에서 3개의 화합물을 분리하였으며, GC/MS 분석에서 phytol, β-sitosterol 및 (-)-Loliolide으로 동정하였다. To investigate potential medicinal or functional uses of Eriobotrya japonica, this study focused on the isolation and identification of antioxidant compounds from Eriobotrya japonica leaves. Various solvents were extracted from the leaves, and their scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals was measured, in addition to their superoxide dismutase-like activity, polyphenol compounds, and flavonoid content. Ethyl acetate extract exhibited the strongest scavenging effect in a 0.2 mM solution of DPPH (63.24±2.20%, 81.83±2.10%, and 93.15±2.31% in 0.3, 0.7, and 1.0 mg/ml sample concentrations, respectively). The antioxidant effect of the ethyl acetate extract and methanol extract were generally stronger than that of n-hexane extract. The extracts were further purified by repeated silica gel column chromatography. The antioxidant compounds were identified as phytol, β-sitosterol, and (-)-loliolide using GC/MS.
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반응표면분석법에 의한 머위 잎의 petasin 추출공정 최적화
이동완(Dong Wan Lee),이세열(Se Yeul Lee),정헌식(Hun Sik Chung),최영환(Young Whan Choi),임동순(Dong Soon Im),이영근(Young Guen Lee) 한국생명과학회 2013 생명과학회지 Vol.23 No.11
머위 잎에서 알레르기성 천식에 효과적 치료제로 알려져 있는 petasin을 효율적으로 추출하기 위해 반응표면분석법을 사용하여 petasin 추출공정 최적화를 실시하였다. Box-Behnken design에 따라 설정한 에탄올 농도(40-80%), 추출 rpm (125-225), 추출시간(1-3 hr)을 독립변수로 하고 추출물의 특성 즉, 추출수율과 petasin 함량을 종속변수로 하여 분석을 실시하였다. 추출물의 petasin 함량은 에탄올 농도, 추출 rpm, 추출시간의 유의적인 영향을 받으며 특히, 에탄올 농도의 영향이 크며 이의 수준이 높아짐에 따라 증가하는 것으로 나타났다. 추출조건에 따른 petasin의 거동은 유의적인 회귀식으로 설명이 가능한 것으로 확인되었다. 반응표면분석 결과, 머위 잎으로부터 petasin의 추출에 최적인 조건으로 에탄올 농도는 79.92%, 추출 rpm은 178.10, 추출시간은 2.06 hr로 각각 결정되었다. Petasin extracted from Petasites japonicus leaves has been well known to be effective in the treatment of allergic asthma. This study was carried out to optimize the extraction process of petasin from P. japonicus leaves by response surface methodology (RSM). The dried powder of P. japonicus leaves was extracted at ethanol concentrations ranging from 40% to 80%, extraction rpm ranging from 125 rpm to 225 rpm, and extraction time ranging from 1 to 3 hours. The effects of the extraction conditions on the dry yield and petasin content of the extracts were investigated using a second-order Box-Behnken design. The petasin content was significantly affected by ethanol concentration, extraction rpm, and extraction time, tending to increase more with increasing ethanol concentration. The optimum condition for petasin extraction from Petasites japonicus leaves was 79.92% in ethanol concentration, 178.10 rpm in extraction rpm, and 2.06 hours in extraction time, respectively.
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이금분,이세열,김용수 大田大學校 産業技術硏究所 2001 산업기술연구소 論文集 Vol.12 No.2
This paper presents an image contrast enhancement technique for enhancing the low contrast images using the fuzzy neural network. The low pictorial information of a low contrast image is due to the vagueness or fuzziness of the multivalued levels of brightness rather than randomness. Fuzzy image processing technigue has three main stages, namely, image fuzzification. modification of membership values, and image defuzzification. For the fuzzification and defuzzification, we need to select a suitable crossover point. The problem of crossover point selection can be considered as the two-category classification problem. The fuzzy neural network is used to classify the image into two classes. The proposed method is applied to several experimental images with 256 gray levels and the results are compared with those of the histogram equalization technique. We utilized the index of fuzziness as a measure of image quality. The results show that the proposed method is better than the histogram equalization technique.
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