• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.43-46
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• 2008

The aim of present study was to examine the inhibitory effects of hydroxamic acid derivatives on the melanogenesis. We found that hydroxamic acid moiety was important for anti-melanogenic activity. Compounds 1a and 1b strongly inhibited melanin synthesis via deactivation of tyrosinase. Hydroxamic acid has metal ion chelating ability which is similar to that kojic acid, however, anti-tyrosinase mechanism of compounds 1a and 1b was different from that of kojic acid. They showed noncompetitive inhibition kinetics

• Archives of Pharmacal Research
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• 제22권2호
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• pp.202-207
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• 1999

New series of catechol ether type derivatives 5, 6 have been synthesized and applied to biological tests. Even though it is ap preliminary data, some of our target molecules show the promising result against PDE IV inhibition. SAR and biological studies with studies with synthetic compounds will be discussed in detail.

• 기술혁신학회지
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• 제5권1호
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• pp.16-25
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• 2002

그 동안 R&D와 관련된 많은 연구는 다양한 성장모형을 이용해 경제성장과 연구개발 투자사이의 관계를 보이는데 중점을 두어왔으나, 디지털 경제에서의 지식 혁신에 의한 R&D활동의 성장패턴을 보이는 연구는 이루어지지 않고 있다. 따라서 본 연구에서는 W기업의 생산과정에서 R&D활동에 따른 비중의 변화가 생산성을 증가시키는 성장의 패턴을 다양하게 할 수 있음을 보이고자 한다.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2002년도 춘계학술대회
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• pp.19-33
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• 2002

그 동안 R&D와 관련된 많은 연구는 다양한 성장모형을 이용해 경제성장과 연구개발 투자사이의 관계를 보이는데 중점을 두어왔으나, 디지털 경제에서의 지식 혁신에 의한 R&D활동의 성장패턴을 보이는 연구는 이루어지지 않고 있다. 따라서 본 연구에서는 IT기업의 생산과정에서 R&D활동에 따른 비중의 변화가 생산성을 증가시키는 성장의 패턴을 다양하게 할 수 있음을 보이고자 한다.

• Applied Biological Chemistry
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• 제46권3호
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• pp.246-250
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• 2003

양하(Zingiber mioga Roscoe) 근경의 에탄을 추출물을 재료로 Staphylococcus aureus, Bacillus subtilis 및 B. cereus에 대한 activity-guided fractionation을 실시하여 항균성 물질 세가지준 얻었다. 항균력실험 결과, 화합물 I과 111은 세가지균주 모두에 활성이 있었고, 화합물 II에서는 B. subtilis과 B. cereus에서만 활성이 나타났다. 그 중에서 가장 활성이 강한 화합물 I을 Bioscreen C로 optical density(600 nm)를 측정하여 증식억제실험을 한 결과 10 ppm 처리시 B. subtilis과 B. cereus에서 72시간동안 강한 증식억제효과를 나타내었으며, S. aureus에서는 25 ppm 처리시 72시간동안 완전증식억제효과를 나타내었다. $1^H-NMR$, ${13}^C-NMR$, DEPT,$1^H-1^H$ COSY, HMQC, HMBC 및 IR 스펙트럼 등을 분석한 결과 화합물 I, II, III은 labdane-type diterpene인 $(E)-8{\beta}(17)-epoxylabd-12-ene-15,16-dial(C_{20}H_{30}O_3,\;MW=318)$, $galanolactone(C_{20}H_{30}O_3,\;MW=318)$ 그리고 galanal A($C_{20}H_{30}O_3,\;MW=318$)로 각각 동정되었으며, 이들은 양하의 근경에서는 처음 분리된 것이다.

• Preventive Nutrition and Food Science
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• 제6권3호
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• pp.137-141
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• 2001

Water-soluble crude polysaccharide (TM-1) prepared from the leaves of Teucrium viscidum var. miquelianum was fractionated into three polysaccharide fractions, TM-2, TM-3 and TM-4 by the addition of cetyltrimethylammonium bromide. The major polysaccharide fraction, TM-2, consisted of glucose, galactose, rhamnose, mannose, glucuronic acid and galacturonic acid, and all fractions contained galactose and glutose as the major neutral sugars. TM-4 showed the highest anti-complementary activity. When TM-4 was futher fractionated by anion exchange chromatography, TM4- II a and TM4-II b showed the most Potent anti-complementary activity. TM4- II a was composed mainly of galactose, arabinose and glucose in the molar ratios of 2.13 : 0.94 : 1.00 respectively, and contained a small amount of galacturonic acid and glucuronic acid.

• 대한본초학회지
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• 제22권4호
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• pp.219-225
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• 2007

Objectives : We investigated the anti-aging effects on skin with Saccharomyces fermented modified Kyungohkgo extract (SFKE). Methods : Fermented modified Kyungohkgo extracts by 14 different kinds of microorganism were prepared and most effective Saccharomyces fermented modified Kyungohkgo extract among these was selected for anti-aging agent. We measured various effects related to skin such as scavenging activity against free radical, cell proliferation, collagen synthesis and toxicity of SFKE were evaluated and compared with modified Kyungohkgo extract (KE). Results : Free-radical scavenging activity and cell proliferating ratio of SFKE were 2 and 8 times higher than those of KE. The SFKE could significantly increase the collagen synthetic ratio compared with KE treated group. SFKE showed no toxicity at all tested concentrations. Conclusions : The results of our study propose that SFKE have good anti-aging effects on skin.

• 한국약용작물학회지
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• 제20권6호
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• pp.454-460
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• 2012

In this study, kaempferol and its rhamnosides (${\alpha}$-rhamnoisorobin, afzelin, kaempferitrin) were isolated electively by bioconversion technology from Hibiscus cannabinus L. leaves to evaluate the anti-wrinkles effects and anti-microbial effects. In order to evaluate anti-wrinkles activity, reduction of expression matrix metalloproteinase-1 (MMP-1) protein and proliferation/ pro-collagen production were investigated. Kaempferol and ${\alpha}$-rhamnoisorobin showed inhibition activity of MMP-1 generated to compared to positive control. In HaCaT cell proliferation assay, kaempferol and ${\alpha}$-rhamnoisorobin significantly promoted cell proliferation in a concentration-dependent manner. In addition, procollagen synthesis assays (by HDF-N cell) showd that TGF-${\beta}$ induced procollagen production and also, all four kinds of experimental significantly promoted procollagen synthesis in a concentration-dependent manner. Kaempferol and ${\alpha}$-rhamnoisorobin exhibited strong antimicrobial activities on five of microbes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2011년도 춘계학술발표회
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• pp.98-99
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• 2011

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1303-1310
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• 2008

Inhibitors of farnesyltransferase (FT), a key enzyme in the post-translational modifications of Ras proteins, have been extensively studied as novel anticancer agents in the preclinical stages, some of which are currently in clinical development. Previously, it has been reported that a novel FT inhibitor LB42907 inhibits Ras farnesylation in the nanomolar range in vitro. The aim of this study was to assess the antitumor efficacy of LB42907 in vitro and in vivo. Anchorage-independent growth of various human tumor cell lines was potently inhibited by treatment with LB42907, comparable to other FT inhibitors in clinical development. In the nude mouse, oral administration of LB42907 demonstrated potent antitumor activity in several human tumor xenograft models including bladder, lung and pancreas origin. Interestingly, significant tumor regression in EJ (bladder) and A549 (lung) xenografts was induced by LB42907 treatment. The effectiveness of LB42907 was also investigated in simultaneous combination with paclitaxel, vincristine, cisplatin or gemcitabine against NCI-H460, A549, and HCT116 cells in vitro using median-effect analysis. LB42907 markedly synergized with most anticancer drugs tested in this study in NCI-H460 cell. In contrast, LB42907 displayed antagonism or partial synergism with these drugs in A549 and HCT116 cells, depending on the class of combined drugs and/ or the level of cytotoxicity. Our results demonstrate that LB42907 is an effective antitumor agent in vitro and in vivo and combination of LB42907 with other chemotherapeutic drugs results in synergistic or antagonistic effects mainly in a cell line-dependent manner. Further preclinical study is warranted.