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      • α-클로로-α-(메틸티오)아세톤을 이용한 벤조푸란 유도체의 합성

        崔洪大,徐弼子,孫炳華 동의대학교 기초과학연구소 1999 基礎科學硏究論文集 Vol.9 No.1

        Benzofuran ring을 포함하는 다수의 화합물이 생리활성을 발현하는 의약품으로 개발되어있고 아울러 Benzofuran ring의 모핵 구조를 가진 천연물로서 천식, 위궤양 및 고혈압 등에 유용한 물질도 알려져 있다. Benzofuran ring의 합성법 중 대표적인 예로는 고온에서 arylalkyl ether의 cyclodehydration, aryloxyacetone의 탈수제에 의한 cyclization 및 o-allylphenol 류의 오존분해와 cyclization을 경유하는 방법과 (2-methoxyphenyl)ethynes을 2,4,6-trimethylpyrideine 중 lithium iodide로 처리하는 방법이 보고된바 잇다 .이들 제법은 출발물질의 합성이 용이하지 않고, 고온과 강산성의 격렬한 방응조건을 요구하고 있다.

      • 치환페놀류로부터 2-메틸벤조푸란 유도체의 합성

        崔洪大,徐弼子,孫炳華 동의대학교 기초과학연구소 2000 基礎科學硏究論文集 Vol.10 No.1

        황원자가 α-탄소상의 양이온을 안정화시키는 성질을 가짐은 널리 보고되어있다. 이 α-thiocarbocations를 이용한 탄소-탄소결합형성반응에 관한 연구의 일환으로서, 저자동은 Scheme 1처럼 Friedel-Crafts반응 또는 Pummerer반응조건하에서 발생되어지는 황원자와 acyl기(nitrile기를 포함)에 인접한 탄소양이온(1-acyⅠ-1-thiocarbocations)과 방향족 화합물로부터 arylacctic acid와 arylacetone 및 arylacetonitrile의 간편한 합성법을 개발하였다. 또한 1-acyⅠ-1-thiocarbocations를 적용하여 phenylacetic acid의 모핵구조를 포함하는 소염제인 aryalkanoic acid의 제법을 보고하였다.

      • 2-Chloro-2-(methylthio)acetophenone을 이용한 2-페닐벤조[b]퓨란 유도체의 합성

        崔洪大,徐弼子,孫炳華 동의대학교 기초과학연구소 2000 基礎科學硏究論文集 Vol.10 No.1

        It is well known that 2-arylbenzo[b]furan derivatives are occured in natural products such as Styrax obassia, Sophora tomentosa, and Krameria ramosissima. In the course of our search on the carbon-carbon bond formation utilizing 1-acyl-l-thiocarbocationic intermediates, we showed that the reaction of substituted phenols with α-chloro-α-(methylthio)acetone (1) in the presence of Lewis acid provided a convenient method for the 2-methylbenzo[b]furans (3) through the reductive desulfurization of the resulting products (2) (Scheme 1). The present paper describes the one-step synthesis for 2-phenylbenzo[b]furan derivatives from the reaction of phenol or cresol isomers with 2-chloro-2-(methylthio) acetophenone in the presence of zinc chloride. Many procedures have been reported for the preparation of 2-phenylbenzofuran ring. Among them, the most frequently employed method is based upon the cyclodehydration reaction of aryloxyacetone moiety with standard dehydrating reagents(H₂SO₄, ZnCl₂, POCl₃, KOH or PPA).

      • Furfural 어류급독성 및 조직병리에 관한 연구

        이철우,최성수,최필선,이상협,이길철,박광식 한국환경독성학회 1997 환경독성보건학회지 Vol.12 No.2

        Furfural, an organic solvent, is widely used as synthetic component material in producing chemical products. However, furfural has been reported that it shows strong toxicities to human being showing intense stimulus to skin, eyes, mucous membrane and nerve system. It is also known to cause anemia, liver cirrhosis, kidney failure and genetic toxicity in the human being working in the exposed area. LD50 of furfural for peritoneal injected mouse has been known around 20mg/kg, but the acute toxicity on aquatic organisms such as fish, daphnid or algae are not well known, compared to those on rodents. In this experiment, we studied on the fish toxicity of furfural using Japanese Meclaka (Oryzias latipes) and Common Carp (Cyprinus carpio). We also observed histological changes in the fish organs. The LC50s were 12.8 mg/L in Japanese Medaka and 21.8 mg/L in Common Carp, respectively. When Common Carps were exposed to 120 mg/L of furfural concentration for 30 minutes, blood congestion in gills and lysis of secondary lamella were shown. Though the muscle of caudal fin was not completely eroded, its epidermic cells were shown to be necrotic in various parts. Tissue atrophy and cell necrosis were also shown in the liver of Common Carps exposed to furfural. From these results, furfural seems to cause histological damages on liver, an internal organ as well as on external organs such as gills and fins eventhough the fish were exposed for a short-term.

      • Humic acid가 카드뮴 어독성에 미치는 영향

        류지성,정규혁,최필선,이길철,최덕일,최성수,류홍일,박광식 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1

        Cadmium, a major aquatic pollutant in many parts of the world, is toxic and readily accumulated in aquatic organisms. It mainly exists in water as complexes with organic ligands such as dissolved organic carbon and this complexation is known to have effects on the aquatic toxicities. In this study, acute toxicity, histology, and bioaccumulation were studied to evaluate effects of humic acid on cadmium toxicity and bioavailability to fish using Oryzias latipes and Cyprinus carpio. 96h-LC50 of cadmium was 6.38 ㎎/L using Oryzias latipes. However, the mortality showed the dose-dependent decrease when humic acid was added to the test solution. When fish were exposed to 5㎎/L of cadmium, histological changes in the exposed organs(caudal fins, gills, kidney, liver, and gut) of Cyprinus carpio were decreased by humic acid, especially in kidney and liver. Bioaccumulation of cadmium also decreased by treatment of humic acid. It seems that the formation of complexes between cadmium and humic acid may decrease bioavailability of cadmium to fish, and thus reduce the toxic effects of cadmium.

      • Humic acid가 카드뮴 어독성에 미치는 영향

        류지성,정규혁,최필선,이길철,최덕일,최성수,류홍일,박광식 한국환경독성학회 1998 환경독성보건학회지 Vol.13 No.1

        Cadmium, a major aquatic pollutant in many parts of the world, is toxic and readily accumulated in aquatic organisms. It mainly exists in water as complexes with organic ligands such as dissolved organic carbon and this complexation is known to have effects on the aquatic toxicities. In this study, acute toxicity, histology, and bioaccumulation were studied to evaluate effects of humic acid on cadmium toxicity and bioavailability to fish using Oryzias latipcs and Cypriruts carpio. 96h~LC50 of cadmium was 6.38 mg/L using Oryzias latipes. However, the mortality showed the dose-dependent decrease when humic acid was added to the test solution. When fish were exposed to 5 mg/L of cadmium, histological changes in the exposed organs (caudal fins, gills, kidney, liver, and gut) of Cyprinifs carpio were decreased by humic acid, especially in kidney and liver. Bioaccumulation of cadmium also decreased by treatment of humic acid. It seems that the formation of complexes between cadmium and humic acid may decrease bioavailability of cadmium to fish, and thus reduce the toxic effects of cadmium.

      • 자동영상추적장치를 이용한 카드뮴 처리 Oryzias latipes의 행위독성연구

        류지성,이철우,최필선,최성수,류홍일,이길철,정규혁,박광식 한국환경독성학회 1999 환경독성보건학회지 Vol.14 No.4

        Changes in certain fish behaviors are known to be very sensitive indicators of sublethal exposure to environmental contaminants. Therefore, behavioral toxicity tests, if properly designed, can be very useful to assess the influence of hazardous chemicals on fish. However, quantitative analysis of xenobiotic -mediated changes in locomotor behavior in fishes are rare, due mainly to the methodological difficulties. In general, fish movement has been known to be hypertrophic or hypotrophic according to the chemicals. As a study of fish behavioral toxicities, we quatified the swimming movement of Orydas latipes using computer-automated video tracking system. Oryzias latipes was exposed to cadmium of 128 mg/L for 1 hour in a limited aquaria, then the total swimming distance, the average swimming velocity, the histogram of turning angles, and the turning frequency were analyzed. Fish treated with cadmium showed decreased swimming activities, decreased velocity, and decreased turning frequency, which means hypotrophic activity. From these results, the computer-automated video tracking system of this study seems to be a good tool for the evaluation of the potential ecotoxicological studies.

      • SCOPUSKCI등재

        Assessing Competence for Adventitious Shoot Formation in Hypocotyl-Explant Cultures from Catharanthus roseus Cultivars

        Choi, Pil-Son,Lee, Soo-Young,Chug, Hwa-Jee,In, Dong-Soo,Choi, Dong-Wook,Liu, Jang Ryol 한국식물학회 2003 Journal of Plant Biology Vol.46 No.2

        Hypocotyl explants from 22 cultivars of Catharanthus roseus were cultured on various shoot-inducing media to assess their competence for adventitious shoot formation. The Murashige and Skoog (MS) media had been supplemented with 14 μM zeatin and 2.5 μM indole-3-butyric acid (IBA), 4.5 μM BA and 0.5 μM a-naphthaleneacetic acid (NAA), or 14 μM thidiazuron and 2.5 μM IBA. After eight weeks, the explants from 'Cooler Raspberry Red' showed the greatest frequency of adventitious shoot formation, followed by 'Cooler Orchid' and 'Cooler Treated'. The highest frequency (86.7%) for 'Cooler Raspberry Red' was attained on the mediμM enhanced with 14 μM zeatin and 2.5 μM NAA. Excised adventitious shoots were then readily rooted on a half-strength MS basal mediμM. Afterward, the regenerated plantlets were transferred to potting soil and grown to maturity in a greenhouse.

      • KCI등재

        Somatic Embryogenesis and Plant Regeneration in Tissue Cultures of Artemisia annua L.

        Choi, Pil-Son,Min, Sung-Ran,Ko, Suk-Min,Liu, Jang-R. The Korean Society of Plant Biotechnology 2007 식물생명공학회지 Vol.34 No.3

        Mature seeds of Artemisia annua L. were placed onto Murashige and Skoog's (MS) medium supplemented with $4.52\;{\mu}M$ 2,4-dichlorophenoxyacetic acid (2,4-D). After 6 weeks of culture, off-white, compact calluses were formed on the plumule of seedlings at a frequency of 5.9%. Calluses were subcultured on the same medium. After an additional 2 weeks of subculture, calluses produced a few somatic embryos at a frequency of 28.8%. Upon transfer to MS basal medium, calluses producing a few somatic embryos gave rise to numerous somatic embryos, which subsequently developed into plantlets. Plantlets were successfully transplanted to potting soil and grown to maturity in a greenhouse.

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