• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1988년도 학술대회지
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• pp.19-24
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• 1988

[ $L_{1210}$ ] 세포에 대하여 세포독성이 있는 두개의 새로운 polyyne을 인삼으로부터 분리하였는데 이들은 acetylpanaxydol과 panaxy-dolchlorhydrin이다. Panaxydol 유사체의 C-9 위치에 있는 epoxy group과 C-10 위치의 heptyl group 은 세포독성을 강화시켜준다. Panaxydol의 epoxy group 은 cis와 trans 이성체들간의 세포독성 차이는 없다. Panaxydol과 이들 이성체들에서 세포독성을 발휘하는 필수구조는 hept-l-en-4.6-diyn-3-ol이다.

• Clinical and Experimental Pediatrics
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• 제52권7호
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• pp.752-755
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• 2009

It is well known that hemodynamic load is one of the most important determinants of cardiac structure and function. Circadian variations in blood pressure (BP) are usually accompanied by consensual changes in peripheral resistance and/or cardiac output. In recent years, reduction in circadian variations in BP and, in particular, loss of nocturnal decline of BP were observed in hypertensive patients with left ventricular hypertrophy (LVH). The patients with only a slight or no loss of nocturnal decline of BP were considered "non-dippers". Regression of LVH was observed after prolonged antihypertensive therapy. Restoration of the circadian rhythm of BP was also observed. However, the classification of patients into "dippers" and "non-dippers" is arbitrary and poorly standardized and repeatable, and in the recent studies, most hypertensive patients with LVH were "dippers". Therefore, we should be particularly cautious about the conclusions drawn using this index. On the other hand, reduced activity of low-pressure cardiopulmonary baroreceptors and impaired day-to-night modulation of autonomic nervous system activity were observed in patients with only LVH. Therefore, alterations in cardiac structure may impair BP modulation. On the other hand, the reverse can also be trueprimary alterations in BP modulation, through a persistently elevated afterload, can increase cardiac mass. Thus, the interrelationship between cardiac structure and BP modulation is complex. Hence, new and more specific methods of evaluating circadian changes in BP are needed to better clarify the abovementioned reciprocal influences.

• Journal of Electrochemical Science and Technology
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• 제8권3호
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• pp.169-182
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• 2017

Iron and nitrogen codoped carbon (Fe-N/C) catalysts have emerged as one of the most promising replacements for state-of-the-art platinum-based electrocatalysts for oxygen reduction reaction (ORR) in polymer electrolyte fuel cells. During the last decade, significant progress has been achieved in Fe-N/C catalysts in terms of ORR activity improvement and active site identification. In this review, we focus on recent efforts towards advancing our understanding of the structure of active sites in Fe-N/C catalysts. We summarize the spectroscopic and electrochemical methods that are used to analyze active site structure in Fe-N/C catalysts, and the relationship between active site structure and ORR activity in these catalysts. We provide an overview of recently reported synthetic strategies that can generate active sites in Fe-N/C catalysts preferentially. We then discuss newly suggested active sites in Fe-N/C catalysts. Finally, we conclude this review with a brief future outlook.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.126-126
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• 1998

Studies on natural products are of great interest, due to the limits in development of synthesized medicine and its side effects. Deer antler is the most popular cure-all type drug among Asian folk medicines. In this study, we newly isolated the biologically active components from chloroform extract and 70% ethanol extract of deer antler, and analyzed their structures. First, the structure of monoacetyldiglyceride in deer antler was identified. To investigate the structure-activity relationship of monoacetyldiglycerides, we synthesized diverse substituted glycerides from glycerol, and confirmed their structures by spectroscopic methods. Among seven structurally-interesting compounds tested in this study, compound 1,2,3,5, and 6 showed activity toward [Ca$\^$2+/]$\_$i/ increase in fura-2 loaded rat pancreatic acinar cells. Second, 70% ethanol extract of deer antler stimulated insulin release from rat pancreatic islets. We found the most effective fraction was CN-Es-8 in 70% ethanol extract, and it increased intracellular Ca$\^$2+/ concentration in pancreatic ${\beta}$-cell.

• 한국식품영양학회지
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• 제3권2호
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• pp.123-132
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• 1990

Sweet potato $\beta$-amylase is a tetrameric enzyme consisting of four identical polypeptide chains with a molecular weight of 5.6$\times$104, though most of the other $\beta$-amylases are monomeric enzymes. But, the relationship between subunit structure and catalytic function of the enzyme is not known. This study was done to know what the function of the subunit structure of the enzyme is. We obtained the monomer from the enzyme by the treatment of SDS, alkali pH buffer and urea. But the monomer had not activity. We tried to prepare the active monomer from the enzyme by the modification with periodate-oxidized soluble starch , In the result, we succeeded in isolating an active monomer as an oxidized soluble starch-conjugated form The active monomer had 57% of the original activity, 13.2% of the sugar and the molecular weight was estimated to be 5.4$\times$104. This results suggest that the tetrameric form of the enzyme is a most stable one and exists in nature, and the subunit structure of the enzyme Plays an important role in stabilization but not catalytic function.

• 대한화장품학회지
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• 제23권3호
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• pp.86-91
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• 1997

Some natural polyhydroxy aromatic compounds have inhibitory activity against tyrosinase, key enzyme for formation of melanin pigment. We examined the structure-activity relationship of the natural polyhydrowy aromatic compounds and synthesized a number of new derivetives through various methods. Skin lightening effects of these compounds were examined through inhibition of mushroom tyrosinase and inhibitory of melanogenesis on B-16 melanoma cells. These new compounds showed strong inhibitory activity against tyrosinase. Good lightening effects sue to inhibition of melanogenesis were observed from several resorcinol and pyrogallol derivatives. In toxicological tests such as skin primary irritation and sensitization, the above compounds were sufficiently safe for cosmetic use.

• Archives of Pharmacal Research
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• 제21권2호
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• pp.193-197
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• 1998

A number of substituted isoquinolin-1-ones, possible bioisosteres of the 5-aryl substituted 2,3-dihydroimidazo[2,$1-a$]isoquinolines, were synthesized and tested for their antitumor activity against five different human tumor cell lines. O-(3-hydroxyporpyl) substituted compound (15) exhibited the best antitumor activity which is 3-5 times better than 5-[$4^1$-(piperidinomethyl)phenyl]-2,3-dihydroimidazo[2,$1-a$]isoquinoline (1).

• Archives of Pharmacal Research
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• 제21권1호
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• pp.24-29
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• 1998

To search for the anti-diabetic principle from the stem bark of Kalopanax pictus, seven kinds of chemical constituents including hederagenin glycosides and phenolic glycosides wre isolated. The anti-diabetic evaluation of these isoltes in the streptozotocin-induced diabetic rats exhibited that kalopanaxsaponin A has a potent anti-diabetic activity in contrast to a mild activity of hederagenin. In addition, significant hypocholesterolemic and hypolipidemic activities of kalopanaxsaponin A and hederagenin were observed. The structure-activity relationship of kalopanaxsaponin A was also investigated in the present work.

• Archives of Pharmacal Research
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• 제24권4호
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• pp.276-280
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• 2001

Substituted isoquinolin-1-ones (1) were synthesized to test their in vitro anticancer activity. 3-Biphenyl-H-methylisoquinolin-1-one (7) showed the most potent anticancer activity against five different human cancer cell lines.

• Bulletin of the Korean Chemical Society
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• 제10권1호
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• pp.1-5
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• 1989

The nonempirical molecular connectivity indexes of a number of mono- and disubstituted purines were calculated. Very good correlations were obtained between anticancer activity (log 1/c) and toxic activity (log 1/) of tIhese compounds and their molecular connectivity indexes and physicochemical constants. Our structure-activity relationship is discussed briefly in relation to theories of general QSAR.