• Archives of Pharmacal Research
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• 제26권9호
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• pp.686-696
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• 2003

Ethyl (coumarin-4-oxy)acetate 1 was prepared through the reaction of 4-hydroxycoumarin with ethyl bromoacetate. Compound 1 was allowed to react with hydrazine hydrate to produce coumarin-4-oxyacetic hydrazide 2. The synthesis of N-(arylidene and alkylidene)-coumarin-4-oxyacetic hydrazones 3-20 was performed. The preparation of 2-substituted-3-[(coumarin-4-oxy) acetamido]thiazolidinones 21-26 and 2-[(coumarin-4-oxy )methyl]-4-acetyl-5-substituted-$\Delta^2$-1,3,4-oxadiazolines 27-33 was performed by the reaction of the hydrazones 3, 4, 7, 9, 12, 14 with mercaptoacetic acid and the hydrazones 3, 4, 5, 7, 12, 15, 16 with acetic anhydride, respectively. The antiviral activities, cytotoxicities and structure-activity relationship (SAR) towards different microorganisms of the prepared compounds were studied.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.364.2-364.2
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• 2002

(S) and (R) 12-HETE. endogenous eicosanoids. have recently been discovered to be implicated in a number of important biological activities. In particular. it has recently been reported by us that both the capsaicin-activated channel of sensory neurons and the cloned capsaicin receptor (VR1) are activated by the eicosanoids including these metabolites. We report herein a novel and efficient asymmetric synthesis of highly enantiomerically enriched 12(S)-HETE via enzymatic kinetic resolution of the key allylic alcohol synthon. (omitted)

• 대한화장품학회지
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• 제37권3호
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• pp.211-218
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• 2011

Glycogen synthase kinase 3 beta (GSK3${\beta}$)의 선택적 저해제인 Kenpaullone가 B16 멜라노마 및 사람의 멜라노사이트에 미치는 멜라닌 합성능을 조사하였다. Kepaullone은 B16 멜라노마 및 사람의 멜라노사이트에 대하여 세포증식에는 영향이 없는 범위 내에서 농도 의존적으로 멜라닌 합성을 촉진시켰다. B16 멜라노마 세포에 Kenpaullone을 첨가 48 h 후 tyrosinase 활성이 증가하였으며, 농도별 처리에 대하여 tyrosinase 단백질의 발현 및 tyrosinase mRNA양이 증가함을 관찰하였다. 결론적으로 Kenpaullone는 B16 멜라노마 세포에서 tyrosinase 효소의 발현을 증가시켜 멜라닌 합성을 촉진하는 것으로 판단되어진다. 따라서 GSK3${\beta}$ 저해제가 멜라닌 합성을 촉진시키는 결과는 백반증과 같은 저색소관련 질병의 치료제 개발의 가능성을 갖고 있는 소재로서 응용가능하리라고 판단되어진다.

• 대한화학회지
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• 제5권1호
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• pp.33-37
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• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

• 한국식품과학회지
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• 제44권5호
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• pp.621-627
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• 2012

항염증효과가 있는 기능성 식품 및 의약품 소재의 개발을 위하여 천연 식물 자원으로부터 NOS 저해 활성 물질을 분리하고 그 이화학적인 특성에 대해 알아보기 위해 항염증 효과가 있다고 알려져 있는 58가지의 생약재에서 NO 저해효과를 확인해 본 결과 독활에서 80% 이상의 높은 저해활성을 가진 것을 알 수 있었다. 독활 생약재 에탄올 추출물에서 n-hexane, chloroform, ethyl acetate, n-butanol, water 순으로 용매 분획을 실시한 후 NO 생성 저해 활성을 측정한 결과, chloroform 분획에서 가장 높은 저해 활성을 보여 최종 분리 시료로 선정하였으며, open column chromatography(silica gel, $C_{18}$)를 이용하여 최종적인 활성 물질(AC8-MV)을 분리할 수 있었다. 분리한 활성 물질(AC8-MV)의 순도를 확인하기 위하여 analytical HPLC와 LC-ESI-mass spectrum를 분석한 결과 순수한 단일 물질로 분리 되었음을 확인할 수 있었으며, 차후 nuclear magnetic resonance spectrometer(NMR)를 통해 구조분석을 실시할 것이다. 또한 AC8-MV와 NO저해효과가 유의적으로 차이가 없던 AC8-MVI 활성물질에 대한 순도 및 구조분석을 연구할 것이다. 이를 통해 독활로부터 분리한 활성물질(AC8-MV)이 NO inhibitor 로서 일반 항염증 약물 및 기능성 식품 소재로 실용화될 수 있는 가능성을 시사하였다.

• 한국산업보건학회지
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• 제10권2호
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• pp.124-139
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• 2000

This study was performed to investigate monoacetylbenzidine(MABZ) and benzidine(BZ) hemoglobin adducts among workers who worked at benzidine based dye manufacturing company, and exposed by benzidine and benzidine based dye. The hemoglobin adducts were compared with work environment assessment result for evaluating the usefulness of biological monitoring. The mean BZ hemoglobin adducts among the first synthesis worker's hemoglobin adducts were $40.69{\mu}gBZ/g$ Hb and those of dry and packing workers were $22.14{\mu}gBZ/g$ Hb. The mean of MABZ hemoglobin adducts among 1st synthesis workers were $255.84{\mu}gMABZ/g$ Hb, dispersion worker's hemoglobin adducts were $76.17{\mu}gMABZ/g$ Hb and synthesis worker's hemoglogin adducts were $28.66{\mu}gMABZ/g$ Hb. Work environment assessment results during past 3 years were $0.0065mg/m^3$ and $0.5659mg/m^3$ of benzidine based dye concentration in ambient air of drying and packing only. Dye producing process was categorized by the possibility of exposure to benzidine and benzidine based dye. BZ and MABZ hemoglobin adducts were $19.55{\mu}gBZ/g$ Hb, $119.80{\mu}gMABZ/g$ Hb among workers who exposed by benzidine dihydrochloride and $16.32{\mu}gBZ/g$ Hb, $316.56{\mu}gMABZ/g$ Hb among workers who exposed by benzidine based dye. BZ hemoglobin adducts were not detected among control group and MABZ hemoglobin adducts were $5.33{\mu}gMABZ/g$ Hb. The differences between control and other exposed group was statistically significant. But there was no statistically significant differences between benzidine dihydrochloride exposed process and benzidine based dye exposed group. BZ and MABZ hemoglobin adducts were $2.23{\mu}gBZ/g$ Hb, $76.17{\mu}gMABZ/g$ Hb and $3.46{\mu}gBZ/g$ Hb, $21.33{\mu}gMABZ/g$ Hb. So hemoglobin adducts of MABZ were 5 ~ 30 time higher than those of BZ(P<0.003). Above results indicate that work environment assessment didn't detected benzidine and benzidine based dye in ambient air but biological monitoring detected those of hemoglobin adducts. Two group's hemoglobin adducts exposed benzidine dihydrochloride and benzidine based dye were high level but wasn't statistically significant and those were not detected in control group.

• Korean Chemical Engineering Research
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• 제50권3호
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• pp.417-420
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• 2012

본 연구는 Pd/$SiO_2$ 촉매를 이용하여 2,4-dinitrotoluene(2,4-DNT)을 2,4-toluene diisocyanate(2,4-TDI)로 환원시키는 반응에 관한 연구이다. 반응 조건은 $200^{\circ}C$에서, 일산화탄소를 주입하여 100 bar에서 실험을 진행하였으며, 피리딘이 TDI의 수율에 미치는 영향에 대해 연구 하였다. 반응 실험 결과 피리딘을 넣지 않은 경우 TDI는 생성되지 않았고, 피리딘을 첨가하면 TDI가 생성되었다. 직접 카보닐화를 이용한 균질계상에서의 TDI 합성 연구 결과에 의하면 팔라듐과 피리딘의 착이온이 형성되어 촉매작용을 하는 것으로 알려져 있다. 피리딘을 첨가하였을 경우 TDI가 합성되는 것이 팔라듐 용출에 의한 것인지 확인하기 위해 ICP-AES 분석을 시행하였다. 20 vol% 피리딘을 첨가한 반응에서 반응 후 촉매의 팔라듐 함량이 반응 전에 비해 52% 감소하였다. 이러한 결과는 피리딘을 첨가한 반응실험에서 용출된 팔라듐이 피리딘과 착이온을 형성하는 과정을 거쳐 TDI가 생성되는 것으로 설명될 수 있다.

• Journal of Biosystems Engineering
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• 제40권4호
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• pp.373-393
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• 2015

Background: Cellulose is a ubiquitous, renewable and environmentally friendly biopolymer, which has high promise to fulfil the rising demand for sustainable and biocompatible materials. Particularly, the recent progress in the synthesis of highly crystalline cellulose-based nanoscale biomaterials, namely cellulose nanocrystals (CNCs), draws significant attention from many research communities, ranging from bioresource engineering, to materials science and engineering, to biological and biomedical engineering to bionanotechnology. The feasibility of harnessing CNCs' unique biophysicochemical properties has inspired their basic and applied research, offering much promise for new biomaterials with diverse advanced functionalities. Purpose: This review focuses on vital issues and topics on the recent advances in CNC-based biomaterials with potential, in particular, for bionanotechnology and biological and biomedical engineering. The challenges and limitations of CNC technology are discussed as well as potential strategies to overcome them, providing an essential source of information in the exploration of possible and futuristic applications of the CNC-based functional "green" nanomaterials. Conclusion: CNCs offer exciting possibilities for advanced "green" nanomaterials, driving innovative research and development in a wide range of fields, including biological and biomedical engineering.

• Plant Biotechnology Reports
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• 제4권2호
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• pp.149-155
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• 2010

Expression of the genes for carotenoid bio-synthesis (crt) is dependent on light, but little is known about the underlying mechanism of light sensing and signalling in the cyanobacterium Synechocystis sp. PCC 6803 (hereafter, Synechocystis). In the present study, we investigated the light-induced increase in the transcript levels of Synechocystis crt genes, including phytoene synthase (crtB), phytoene desaturase (crtP), ${\zeta}$-carotene desaturase (crtQ), and ${\beta}$-carotene hydroxylase (crtR), during a darkto-light transition period. During the dark-to-light shift, the increase in the crt transcript levels was not affected by mutations in cyanobacterial photoreceptors, such as phytochromes (cph1, cph2 and cph3) and a cryptochrome-type photoreceptor (ccry), or respiratory electron transport components NDH and Cyd/CtaI. However, treatment with photosynthetic electron transport inhibitors significantly diminished the accumulation of crt gene transcripts. Therefore, the light induction of the Synechocystis crt gene expression is most likely mediated by photosynthetic electron transport rather than by cyanobacterial photoreceptors during the dark-to-light transition.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.1977-1988
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• 2015

β-1,3-glucanosyltransferases play essential roles in cell wall biosynthesis in yeast. Kluyveromyces lactis has six putative β-1,3-glucanosyltransferase genes. KlGAS1-1 and KlGAS1-2 are homologs of Saccharomyces cerevisiae gene GAS1. RT-qPCR indicated the transcription level of KlGAS1-1 was significantly reduced while heterologous protein (thermostable xylanase B) secretion was enhanced during medium optimization. To evaluate if these two events were related, and to improve xylanase B secretion in K. lactis, we constructed KlGAS1-1 and KlGAS1-2 single deletion strains and double deletion strain, respectively. KlGAS1-1 gene deletion resulted in the highest xylanase B activity among the three mutants. Only the double deletion strain showed morphology similar to that of the GAS1 deletion mutant in S. cerevisiae. The two single deletion strains differed in terms of cell wall thickness and xylanase B secretion. Transcription levels of β-1,3-glucanosyltransferase genes and genes related to protein secretion and transport were assayed. The β-1,3-glucanosyltransferase genes displayed transcription complementation in the cell wall synthesis process. KlGAS1-1 and KlGAS1-2 affected transcription levels of secretion- and transport-related genes. Differences in protein secretion ratio among the three deletion strains were associated with changes of transcription levels of secretion- and transport-related genes. Our findings indicate that KlGAS1-1 deletion is an effective tool for enhancing industrial-scale heterologous protein secretion in K. lactis.