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        검색결과 414

        161.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Antioxodative substances in Mulberry leaves were examined. Antioxidative substances in Mulberry leaves were extracted by 80% methanol agueous solution. Antioxidative activity of extract was determined by examining hydrogen donating ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the inhibitory effect on the formation of the peroxide from Linoleic acid in the test tube at 50℃. Antioxidative substance were, then, separated and indentified by thin layer chromatography(TLC), UV-Vis spectrum and High performance liquid chromatography(HPLC) methods. Hydrogen donating ability on DPPH and antioxidative ability on linoleic acid of the extracted antioxidative substance were higher than those of 100ppm butylated hydroxy toluene(BHT). The extracted antioxidative substances were separated by TLC using ethylacetate : chloroform : formic acid : water(8 : 1 : 1 : 1 v/v) as a solvent, and a spot at Rf=0.35 was detected. The spot was scraped from the plate, and extrated by methanol. The extract was analyzed by UV-Vis spetra and HPLC, and chlorogenic acid was identified as a antioxidative substance.
        4,000원
        162.
        1997.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to separate and identify the antioxidative substances in persimmon leaves. The antioxidative substances in persimmon leaves were extracted by methanol. The extract was fractionnated by SEP-PAK cartridge colum. From these results five fractions(F-I~V) were obtained. Antioxidative activity of each fractions was examined by the DPPH methord. The F-II, III and IV showed antioxidative activity and among them F-II and F-III showed the strongest. Five frations were separated by TLC using ethylacetate : chloroform : formic acid : H2O(8 : 1 : 1 : 1 v /v) as the solvent. From these results were obtained spots of Rf 0.71, 0.35 and 0.25. This spots were scraped from the plate and extracted by methanol. The extracts thuse obtained were used for examination of identify by TLC, UV /VIS-spectrophotometer and HPLC. Among them spot of Rf 0.71 were demonstrated to catechin and the spots of Rf 0.35 and 0.25 was suggested to polyphenol substances.
        4,000원
        164.
        1993.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        가을에 파종한 사초용유채(Brassica napus Subsp. oleifera cv. Swiss)의 생육기간 동안의 질소대사와 관련하여 건물수량 및 조단백질의 축적정도를 규명하기 위해. 생육기간중 수량 및 조단백질 함량을 측정하고, 엽내 carbon, nitrogen 및 hydrogen 함량을 비교. 분석하였다. 월동기인 '91년 11월 7일부터 '92년 2월 4일 동안의 생초량 및 건물량의 축적은 매우 적었으며, 엽내 C함량은 건물 1g당 382mg
        4,000원
        165.
        1990.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        담배거세미나방 핵다각체병 바이러스(Spodoptera litura nuclear polyhedroses virus: SINPV) 미생물살충제로 개발하기 위하여 기주식물, 온도 보관조건 및 태양광선에 의한 병원성 및 안정성에 대하여 조사하였다. 콩잎에 살포한 SlNPV의 담배거세미나방 3령과 5령 유충에 대한 은 각각 와 였으며 에 대한 은 3령과 5령에 대하여 각각 7.3일파 8.9일이었다. SINPV는 에서 4시간, 에서 1 10분 처리하였을 때 활성이 저하되었으며 처리시간이 길어질수록 급격한 활성감소현상을 보였다. 또한 SINPV는 동결보관이 나 보관보다 안정적인 활성을 유지하였다. 콩잎표변에 살포한 SINPV는 콩잎표변에 살포한 경우 3일 후에 불활화하였으나 콩잎 이면살포에서는 10일간 활성이 지속되었다.
        4,000원
        166.
        1990.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Changes in chemical components of green tea leaves at different cooking conditions-blanching and frying-were surveyed as a method of utilizing low graded green tea leaves which missed appropriate plucking times. There was no significant difference in protein content during cooking. But contents of chlorophyll, tannin, vitamin C and caffeine were decreased during cooking, contents of chlorophyll and caffeine showed a greater decrease in frying than blanching. Content of total amino acid of green tea leaf was 15.8% and blanching showed bigger diminution of its content in comparision with frying during cooking.
        4,000원
        167.
        1988.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        다른 生長條件(growth chamber, outdoor)과 室素施肥條件(N 0, N 60kg ha-1')에서 자란 Perennial rye- grass잎에 있어서 葉伸長率(LER)과 伸底部位의 空間的 移動 및 細胞의 伸長등을 알아보고자, 잎 基部내 伸長部位의 O~30mm에 pin처리를 하고 일정시간후 Pin hole의 이동거리로서 長을 조사하었으며 표면복 제방법에 의해 細胞의 길이를 측정하였다. Growth chamber에서 자란 목초의 LE
        4,000원
        168.
        1988.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A field experiment was conducted in order to investigate the seasonal changes of leaf growth and related characteristics in three cultivars of orchardgrass; Potomac, Kay and Sumas. The results were summarized as follows: 1. Leaf elongation was increased i
        4,000원
        169.
        1988.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        다른 生長條件(growth chamber, outdoor)과 室素施肥條件(N O, N 60kg ha-1에서 자란 perennial ryegrass잎에 있어서 葉伸長率(LER)과 伸長部位의 空間的 移動 및 細胞의 伸長등을 알아보고자, 잎 基部내 伸長部位의 0~30mm에 pin 처리를 하고 일정시간후 pin hole의 이동거리로서 生長을 조사하였으며 표면복제방법에 의해 細胞의 길이를 측정하였다. Growth chamber에서 자란 목초의 LER은
        4,000원
        170.
        1982.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        벼줄기굴파리의 2화기 피해에 있어서, 이삭 및 잎의 피해양상과 용위화치를 조사한 결과를 요약하면 다음과 같다. 1) 상수율과 공흔발생에 있어, 통일계가 일반계에 비해 높았다. 2) 상수의 피해위치에 있어, 일반적으로 출수기가 이를수록 이삭 하부에, 늦을수록 이삭 상부에 피해를 받았다. 3) 통일계에 있어, 상부 또는 중부 피해 이삭경에 있어서는 상엽에 공흔, 1엽에 무공흔의 경우가 가장 많았고, 하부피해이삭경에서는 모두 무공흔의 경우가 가장 많았다. 4) 용화위치는 지엽과 1엽의 엽초내이었으며, 특히 지엽에 현저히 많았다.
        3,000원
        171.
        1982.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        봄보리 1.5엽기에 흰가루 병균을 접종하여 병진전에 따른 엽내전분함량변화를 측정하였다. 1.5엽기에 접종하였을 때 감수성 품종 Peruvian과 성체식물저항성 품종 Asse에서 상이한 전분축적양상을 보였다. 감염초기에서는 두 품종 모두 전분함량에 다소 변화가 있었다. 병반형성과 포자형성 동안 감수성 품종 Peruvian에서 전분함량감소가 뚜렷하였으나 Asse에서는 병반형성 동안 증가하였고 세포형성전후에 급격히 감소하였다. 감염이 심한 1.5엽에서 Peruvian은 급격한 전분감소를 보였으나 Asse는 감염강도에 관계없이 감염잎에 높은 전분함량을 유지하였다. 봄 보리의 성체식물저항성과 연관시켜 상이한 발육시기에서 흰가루병 감염된 잎의 전분축적역할을 논하였다.
        4,000원
        172.
        1978.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        적성병균에 감염된 배나무 잎에서 건전부위, 병반인접부위 및 병반부위별로 몇가지 가수분해효소의 활성을 측정한 결과는 다음과 같다. 1. Cellulase (Cx), Invertase 및 의 활성은 감염부위에서 보다 건전부위에서 더 높았고 모두 pH 7.0부근인 중성측에서 최대활성이 나타났다. 2. Pectinmethylesterase, Polygalacturonase 및 Phosphatase의 활성은 병반인접부위에서 높았다. 3. Pectinmethylesterase의 활성은 건전부위와 병반 및 그인접부위 간에 pH에 따라 심한 활성차리가 인정되었다.
        3,000원
        173.
        1977.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        백합 (Lilium longiflorum Thumb)의 정부로부터 하부로 내려가면서 잎이 황갈색으로 변하다가 마르며 마른잎은 떨어지지 않고 줄기에 그대로 붙어있으면서 결국 식물이 고사하게 되는 것은 Aphelenchoides ritzemabosi에 의한 피해인 것을 발견했으며 백합이 본선충의 기주식물로 밝혀진 것은 처음이다. 그리고 본선충 형태적 특징을 기술했다.
        4,000원
        174.
        2023.01 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to determine the optimal sound absorption conditions by comparing the sound absorption characteristics of fresh and air-dried leaves of Quercus glauca, the main species of evergreen broadleaf trees (EBLT) in southern Korea. The sound absorption coefficients (SACs) obtained under 18 conditions were comparatively analyzed. The SAC of air-dried leaves improved significantly with increasing leaf layer thickness. The highest average SAC in the fresh leaf group was 0.617, which was observed under the condition of a leaf specimen size of 0.5 × 0.5 cm2 and a leaf layer thickness of 1.75 cm. In a group of air-dried leaves, this was 0.615 under the condition of a leaf specimen size of 0.5 × 0.5 cm2 and a leaf layer thickness of 2.50 cm. The maximum value of SAC for each wavelength was observed under the condition of a leaf layer thickness of 2.50 cm consisting of 0.5 × 0.5 cm2 leaf specimens, ranging from 1,400 Hz to 1,500 Hz.
        175.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        In this study, we were performed to elucidate the antioxidant and anticancer activity by leaves extracts from Acer tegmentosum (AT-L). In DPPH, ABTS radical scavenging activity, the AT-L revealed the high scavenging activity. Especially, the AT-L measured the highest ABTS radical scavenging activity, which is higher than ascorbic acid. The types of human cancer cells for evaluating the anticancer activity were colorectal cancer (SW480), prostate cancer (PC-3), breast cancer (MCF-7), pancreatic cancer (AsPC-1), lung cancer (A549) and liver cancer (HepG2). Human cancer cell viability was measured using MTT assay. Treatment of the AT-L decreased the cell viability and induced apoptosis in SW480 cells. These results suggest that extracts of the AT-L can be used as supplementary material for developing the natural antioxidant and anticancer drug for human cancer cells.
        176.
        2020.10 KCI 등재 서비스 종료(열람 제한)
        구기자 잎을 이용한 특허제품 개발 및 기능성 식품소재에 관한 연구는 다수 진행되고 있으나 구기자 잎을 규격화 표준화하여 대량으로 공급할 수 있는 생산체계는 확립되어 있지 않다. 이에 구기자 육성품종 중에서 잎 생산에 알맞은 품종을 선발하고 가공용 잎을 대량으로 생산할 수 있는 예취시기를 확립코자 하였다. 구기자 11품종 중 잎 생산에 적합한 품종은 ‘명안’이었고, 다른 품종에 비하여 잎이 크고 분얼과 재생력이 왕성하였을 뿐만 아니라 잎 건물수량도 높았다. ‘명안’ 품종에서 구기자 잎 생산에 적합한 예취시기는 초장이 약 60 ~ 70 cm 자랐을 시기였고, 잎 수량은 5월 16일 수확 시 평균 106 ㎏/10a, 6월 20일 수확 시 평균 287 ㎏/10a로서 수확시기가 늦어질수록 직선적으로 증가되었다. 구기자의 지표성분인 베타인 함량을 1.43 ~ 2.63% 범위였고, 품종과 예취시기에 따라 함량이 다른데 생육이 진전 될수록 증가되는 경향이었다. 구기자나무 잎의 주요 생리기능성을 조사한 결과 항고혈압성을 나타내는 ACE 저해활성이 평균 84.4 ~ 90.8%로 높은 편이었고, 나머지 생리기능성은 20% 이하로 낮거나 검출되지 않았다.
        177.
        2019.11 KCI 등재 서비스 종료(열람 제한)
        Chrysanthemum boreale Makino (C. boreale) is widely distributed in Asian countries, and has traditionally been used to treat various inflammatory diseases including bronchitis. In this study, we aimed to isolate biologically active compounds from leaves and stems of C. boreale. Chemical components were purified by column chromatograpy and recyclic HPLC, and characterized from their spectral data (IR, MS, NMR). Biological activity experiments were conducted for Farnesyl-protein transferase (FPTase) activity, apoptosis and nitirc oxide (NO) release. As a results, three sesquiterpene lactones were isolated. Compound 1 (4-methoxy-8-O-acetyl-10-hydroxy-2,11(13)-guaiadiene-12,6-olide) showed strong cytotoxic activities having an average growth inhibition of 50% (GI50) value of 1.89 ㎍/㎖against human colon adenocarcinoma cells. Compound 1 also showed a low half maximal inhibitory concentration (IC50) value of 10 ㎍/㎖ for NO release. In the caspase 3 activity, compound 1 and compound 2 (8-O-(2-carbonyl-2-butyl)-3,10-dihydroxy-4,11(13) -guaiadiene-12,6-olide) exhibited 94% and 90% apoptosis inhibition activity, respectively. Compound 3 (4,8-O-diacetyl -10-hydroxy-2(3),11(13)-guaiadiene-12,6-olide) showed a strong inhibitory effect on FPTase activity with 90% inhibitory activity at a concentration of 100 ㎍/㎖. These results clearly show the presence of lactone compounds in the leaves and stems, which may partially contribute to the pharmacological activity of C. boreale.
        178.
        2019.04 KCI 등재 서비스 종료(열람 제한)
        In this study, we evaluated the effect of branch (STB) and leave (STL) extracts from Sageretia thea on β-catenin level in human colorecal cancer cells, SW480 and lung cancer cells, A549. STB and STL dose-dependently suppressed the growth of SW480 and A549 cells. STB and STL decreased β-catenin level in both protein and mRNA level. MG132 decreased the downregulation of β-catenin protein level induced by STB and STL. However, the inhibition of GSK3β by LiCl or ROS scavenging by NAC did not block the reduction of β-catenin protein by STB and STL. Our results suggested that STB and STL may downregulate β-catenin protein level independent on GSK3β and ROS. Based on these findings, STB and STL may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer and lung cancer.
        179.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        In this study, we evaluated the whitening activity of prethanol A and water extracts from Abeliophyllum distichum Nakai. The extracts were prepared using 0, 50, 70, and 100% prethanol A at 121℃, 1.2 atm for 15 minutes. To confirm effective extraction, the acteoside content of each extract was analyzed with the HPLC-PDA method. The antioxidant activity was evaluated using DPPH and ABTS scavenging activity assays, and the whitening activity was evaluated based on inhibitory activities on the protein and mRNA expression of tyrosinase, tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 2 (TRP-2), and microphthalmia-associated transcription factor (MITF) in B16 F10 cells. Each extract showed strong antioxidant and whitening activity. IC50 values of antioxidant activity from each extract were in order of 100%, 70%, 50%, and 0%. In addition, whitening activity inhibited the protein and mRNA expression of melanin synthesis factor, following the same pattern as antioxidant activity. In conclusion, water and prethanol A extracts of A. distichum showed effective antioxidant and whitening activity and are thus considered to be valuable materials for whitening cosmetics. The results of this study will also provide basic data for the safe and efficient production of A. distichum as a cosmetic material.
        180.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        Aralia cordata (A. cordata), which belongs to Araliaceae, is a perennial herb widely distributed in East Asia. We evaluated the anti-inflammatory effect of stems (AC-S), roots (AC-R) and leaves (AC-L) extracted with 100% methanol of A. cordata and elucidated the potential signaling pathway in LPS-stimulated RAW264.7 cells. The AC-L showed a strong anti-inflammatory activity through inhibition of NO production. AC-L dose-dependently inhibited NO production by suppressing iNOS, COX-2 and IL-β expression in LPS-stimulated RAW264.7 cells. AC-L inhibited the degradation and phosphorylation of IκB-α, which donated to the inhibition of p65 nuclear accumulation and NF-κB activation. Furthermore, AC-L suppressed the phosphorylation of ERK1/2 and p38. These results suggested that AC-L may utilize anti-inflammatory activity by blocking NF-κB and MAPK signaling pathway and indicated that the AC-L can be used as a natural anti-inflammatory drugs.