• Journal of the Society of Cosmetic Scientists of Korea
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• v.29 no.2 s.43
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• pp.193-204
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• 2003

• Archives of Pharmacal Research
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• v.29 no.5
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• pp.369-374
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• 2006

An efficient method for the synthesis of optically active 2-substituted 2,3-dihydro-4-quinolones has been developed. The key features include the introduction of a chiral side chain and the construction of quinolone skeleton by Mitsunobu alkylation and hydroarylation, respectively.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.388.2-388.2
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• 2002

Quercus species have been used for diarrhea. dysentery, dermatitis. haemoptoe, and haemorrhagia in Korean folk medicine. Specially Quercus salicina have been used for diuretic. anti-inflammatory. antiedemic. and litholytic agent. In order to investigate the efficacy of antioxidative activity the activity guided fraction and isolation of physiologically active substance were performed. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.151.2-151.2
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• 2003

For the purpose of the development of a skin-whitening agent, Sophora flavescens was evaluated for tyrosinase inhibitory activity and its active principles were identified followed activity-guided isolation. The ethanol extract and dichloromethane fraction from S. flavescens showed significant inhibition of mushroom tyrosinase. From the dichloromethane fraction, three known prenylated flavonoids, sophoraflavanone G, kuraridin, and kurarinone, were isolated. Compared with kojic acid ($IC_50$=20.5 $\mu$M), these compounds possessed more potent tyrosinase inhibitory activity. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.188.1-188.1
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• 2003

The antiparasitic agent apicidin, which was recently isolated from cultures of Fusarium Pallidoroseum, belongs to a rare group of cyclictetrapeptide fungal metabolites. Apicidin inhibits protozoal HDAC and is orally active against Plasmodium berghei malaria in mice. The biological activity of apicidin appears to be attributable to inhibition of apicomplexan HDAC at low nanomolar concentrations. In the present, we have worked about the synthesis of new apicidin derivatives and discovered that apicidin and some derivatives have mild antitumor activity. (omiited)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.228.1-228.1
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• 2002

Hypoxia in solid tumors is known to contribute to intrinsic chemoresistance. Tirapazamine(TPZ). a hypoxia-selective cytotoxin. showed synergism with radiation or cytotoxic agents. Paclitaxel(PTX) is a highly active anti-cancer agent against Non small cell lung cancer(NSCLC), however. due to poor penetration into central hypoxic region of tumor tissue. combination with TPZ has been suggested to enhance its efficacy. (omitted)

• Journal of KIISE:Information Networking
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• v.32 no.2
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• pp.167-179
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• 2005

In hierarchical Mobile IPv4 Networks the highest FA(Foreign Agent) may experience serious congestion and delay since the highest FA plays a role of CoA(Care of Address) for all mobile nodes in the domain, In this paper, we propose mechanism called 'HRFA(Hierarchical Root Foreign Agent)', which distributes the load imposed on the highest FA. In the proposed HRFA scheme, multiple HRFAs are selected to provide the similar service that is provided by the highest FA. According to which entity determines HRFAs, HRFA scheme is categorized into 'Active' and 'Passive' approaches. HRFA scheme is further categorized into 'All MN(Mobile Node)s' and 'New MNs' approaches, depending on which mobile nodes are assigned to a newly elected HRFA. Through a course of simulations, we investigate the performance of 4 possible combinations of HRFA schemes. We also compare the performance of the proposed HRFA schemes with the LMSP(Local Multicast Service Provider) scheme, which is a scheme to distribute the load of FA for multicast service in hierarchical wireless network domain. The simulation results show that the Passive & New MN approach performs best with respect to both the overhead and the load balancing.

• Journal of Nutrition and Health
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• v.36 no.4
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• pp.382-388
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• 2003

(-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound found in peen tea leaves, and has been known to be one of the most potent catechin species which inhibits cell growth most possibly through an apoptotic cell death. We investigated the apoptotic activity of (-)-EGCG on the human myeloid leukemia cell line, HL-60. Our results of MTT test indicated that (-)-EGCG had a significant antiproliferation effect in HL-60 cells with $IC_{50}$/ (50% inhibition concentration) value of 65 $\mu$M. Giemsa statining of HL-60 cells treated with (-)-EGCG (100 $\mu$M) for 6hrs showed a typical apoptosis-specific morphological change including shrinkage of the cytoplasm, membrane blobbing and compaction of the nuclear chromatin. The DNA fragmentation was observed from the agarose gel electrophoresis of cells treated with (-)-EGCG for 3hrs or longer, and was progressed to a greater degree as treatment time increases. Treatment of the cells with (-)-EGCG (100 $\mu$M) resulted in a rapid release of mitochondrial cytochrome c into the cytosol, and a subsequent cleavage of caspase-3 to an active form in a treatment-time dependent manner. (-)-EGCG (100 $\mu$M) also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP) to an active form in HL-60 cells. Tlken together, (-)-EGCG appears to induce the apoptosis in human myeloid leukemia cells via a caspase-dependent pathway. These results suggest the possible application of (-)-EGCG, the major active compound in green tea, as an antiproliferative agent for cancer prevention.

• Archives of Pharmacal Research
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• v.24 no.3
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• pp.234-239
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• 2001

Three types of learning and memory tests (Morris water maze, active and passive avoidance) were performed in rats following intracerebroventricular infusion of ethylcholine aziridium (AF64A). In Morris water maze, AF64A-treated rats showed the delayed latencies to find the platform iron 6th day after the infusion. In pretrained rats, AF64A caused the significant delay of latency at 7th days but not 8th day. In the active avoidance for the pretrained rats, the escape latency was significantly delayed in AF64A-treatment. The percentages of avoidance in AF64A-treated rats were less increased than those in the control. Especially, the percentage of no response in the AF64A-treated rats was markedly increased in the first half trials. In the passive avoidance, AF64A-treated rats shortened the latency 1.5 h after the electronic shock, but not 24 h. AF64A also caused the pretrained rats to shorten the latency 7th day after the infusion, but not 8th day. These results indicate that AF64A might impair the learning and memory. However, these results indicate that the disturbed memory by AF64A might rapidly recover after the first retrain. Furthermore, these results suggest that AF64A may be a useful agent for the animal model of learning for Spatial cognition .

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.71-80
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• 2022

Lipases (triacylglycerol acylhydrolases [EC 3.1.1.3]) are water-soluble enzymes. They catalyze the hydrolysis of fats and oils. A cold-active lipase from marine Bacillus cereus HSS, isolated from the Mediterranean Sea, Alexandria, Egypt, was purified and characterized. The total purification depending on lipase activity was 438.9 fold purification recording 632 U/mg protein. The molecular weight of the purified lipase was estimated to be 65 kDa using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The optimum substrate concentration, enzyme concentration, pH, and temperature were 1.5 mM, 100 µl, pH 6 and 10℃, respectively. The lipase was tolerant to NaCl concentrations ranging from 1.5 to 4.5%. The lipase was affected by the tested metal ions, and its activity was inhibited by 16% in the presence of 0.05 M SDS. The application of the cold-active lipase for the removal of an oil stain from a white cotton cloth showed that it is a promising biological agent for the treatment of oily wastes and other related applications. To the best of our knowledge, this is the first report of the purification and characterization of a lipase from marine B. cereus HSS isolated from the Mediterranean Sea.