• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1355-1360
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• 2010

In order to search new inhibitors against farnesyl protein transferase (FPTase), a series of 2,3-bis-benzylidenesuccinaldehyde derivatives (1-29) were synthesized and their inhibition activities ($pI_{50}$) against FPTase were measured. From based on the reported results that the inhibitory activities of dimers 2,3-bis-benzylidenesuccinaldehydes were higher than those of monomers cinnamaldehydes, 3D-QSARs on FPTase inhibitory activities of the dimers (1-29) were studied quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. The statistical qualities of the optimized CoMFA model II ($r^2{_{cv.}}$= 0.693 and $r^2{_{ncv.}}$= 0.974) was higher than those of the CoMSIA model II ($r^2{_{cv.}}$ = 0.484 and $r^2{_{ncv.}}$ = 0.928). The dependence of CoMFA models on chance correlations was evaluated with progressive scrambling analyses. And the inhibitory activity exhibited a strong correlation with steric factors of the substrate molecules. Therefore, from the results of graphical analyses on the contour maps and of predicted higher inhibitory active compounds, it is suggested that the structural distinctions and descriptors that contribute to inhibitory activities ($pI_{50}$) against FPTase will be able to applied new inhibitor design.

• 임산에너지
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• 제23권1호
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• pp.45-68
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• 2004

The word of lignin is derived from the Latin word 'ligum' meaning wood. Lignin is complex polymer consisting of coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol unit and has an amorphous, three dimensional network structure which is hard to be hydrolyzed by acid. Lignin is found in the cell wall of plants lignified. The mode of polymerization of these alcohols in the cell wall lead to a heterogeneous branched and cross-linked polymer in which phenyl propane units are linked by carbon-carbon and carbon-oxygen bonds. This polymerization of precursors, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol to lignin is formed by enzymic dehydrolyzation. The reaction is initiated by an electron transfer which results in the formation of resonance-stabilized phenoxy radical. The combination of these radicals produces a variety of dimers, trimers and oligomers and so on. Lignin research has been divided into basic and practical application field. The basic studies contains biosynthesis, chemical structure, distribution in the cell wall and reactivity by reductants, oxidants and organic solvents. The application research will be approached the reaction of lignin in various pulp making involving pulp bleaching and its effect on pulp qualities. Lignin also will be studied for the production of fine chemicals, polymer products and the conservation into an energy source like petroleum oil because the amount of lignin produced in pulp making process is more than 51,000,000 tons per year in the world. Both basic and application research must lay emphasis on the development for the utilization of lignin and the pulping process. But these researches can not be completed without understanding lignin structure containing functional groups. Therefore, this paper was focused on the review of lignin formulation which has been studied since 1948 in chronological order. This review was based on monomers, dimers, trimers and tetramers of phenyl propane unit structures which were isolated and identified by different methods from various wood.ious wood.

• Journal of Photoscience
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• 제10권2호
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• pp.185-187
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• 2003

The preparation and the photophysics of organometallic Pt(II) and Ir(III) complexes with 6-ch1oro-3-phenylpyridazine (H6Clppdz) are reported. $K_2$PtCl$_4$ and IrCl$_3$ㆍn$H_{2}O$ cleanly cyclometalate with H6Clppdz, forming the corresponding chloro-bridged dimers, (6Clppdz)Pt($\mu$-Cl)$_2$Pt(6Clppdz) and (6Clppdz)$_2$Ir($\mu$-Cl)$_2$Ir(6Clppdz)$_2$ in good yield. These chloro-bridged dimers are cleaved with acetylacetone (Hacac) to give the corresponding monomer, (6Clppdz)Pt(acac) and (6Clppdz)$_2$ Ir(acac), respectively. Both complexes show bright orange luminescence at room temperature and the emission wavelengths are different depending on the metal and the structure of complexes. (6Clppdz)Pt(acac) shows two sharp emission bands in shorter wavelength ($\lambda$$_{em}$=541 and 580 nm), while (6Clppdz)$_2$ Ir(acac) shows a broad emission band in longer wavelength ($\lambda$$_{em}$=615 nm). Strong spinorbit coupling due to the heavy metal atom allows for the formally forbidden mixing of the $^1$MLCT with the $^3$MLCT and $^3$$\pi$-$\pi$$^{*}$ states.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1475-1481
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• 2008

B3 antibody specifically binds the $Lewis^Y$-related carbohydrate antigen of many carcinomas, and it is used as a model antibody in this study. In a previous study, the Fab fragment of the antibody was fused to a 38 kDa truncated form of Pseudomonas exotoxin A, PE38, to make Fab-PE38, where PE38 is fused to the Fd fragment of the Fab domain. This parent monomer molecule, Fab-PE38, had no cysteine in the hinge region, and it could not make a disulfide bond to form a disulfide bond bridged homodimer. In this study, we constructed three different kinds of divalent Fab-toxin fusion homodimers where the toxin is fused to the light chain of Fab, $(Fab-PE38fl)_2$. In addition to the PE38 toxin fused to the light chain, these three molecules have different hinge sequences hi, h2, and h3 making Fabh1-, Fabh2-, and Fabh3-PE38fl monomers, respectively. These hinges contain only one cysteine on different positions of the hinge sequence. The disulfide bond between the hinge region of two monomers forms homodimers $(Fabh1-PE38fl)_2$, $(Fabh2-PE38fl)_2$, and $(Fabh3-PE38fl)_2$. The refolding yields of these dimers were 5-16-fold higher than a previously constructed dimer where the PE38 was fused to the Fd fragment $(Fabh2-PE38)_2$ [8]. Our data suggest that the steric repulsion between the two PE38s in $(Fabh1-PE38)_2$ during disulfide bridge formation is relieved by fusing it at the end of the light chain. The best cytotoxicity value of these dimers showed about 2.5-fold higher on an MCF7 cell line than that of the monovalent reference molecule in ng/ml scale, which is 15-fold higher in pM scale.

• 한국재료학회지
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• 제19권3호
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• pp.137-141
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• 2009

Density functional theory was utilized to investigate the growth of an indium nanowire on a Si (001) buckled surface. A site between the edge of two Si dimers is most favorable when the first In atom is adsorbed on the surface at an adsorption energy level of 2.26 eV. The energy barriers for migration from other sites to the most favorable site are low. When the second In atom is adsorbed next to the first In atom to form an In dimer perpendicular to the Si dimer row, the adsorption energy is the highest among all adsorption sites. The third In atom prefers either of the sites next to the In dimer along the In dimer direction. The fourth In atom exhibited the same tendency showed by the second atom. The second and fourth In adsorption energy levels are higher than the first and third levels as the In atoms consume the third valence electron by forming In dimers. Therefore, the In nanowire grows perpendicular to the Si dimer row on the Si (001) surface, as it satisfies the bonding of the three valence electrons of the In atoms.

• 대한화학회지
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• 제37권4호
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• pp.408-415
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• 1993

$CH_4,\;CH_3F,\;CH_2F_2,\;CHF_3$ 과 $NH_3$ 및 H_2O$와의 수소결합 이량체들에 대하여 9s5p/5s 및 9s5p1d/5s1p의 basis sets를 사용하여 체계적인 ab initio 계산을 하였다. 이들 이량체들의 바닥상태성질을 구하여 독립된 단위체들의 대응하는 성질과 비교하였으며, 평형기하구조, 안정화에너지, 쌍극자모멘트 및 분자간 결합의 힘상수 등을 보고하였다. 사슬형 소중합체들에서 수소결합의 비가감적 거동의 결과로부터 일어나는 여러가지 효과들을 논의하고, SCF 근사법의 사용에 따른 체계적 및 조직적인 오차들과 계산결과들의 basis sets 의존성을 지적하였다.

• Elastomers and Composites
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• 제45권4호
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• pp.298-308
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• 2010

패럴린 박막의 기계적 성질과 표면 특성을 개선하기 위해 Xylydene계 다이머(DPX-C, DPX-D, DPX-N)를 사용하여 각각의 다이머에 대한 증착 조건과 투입량에 따른 박막의 두께를 조절함으로써 단일 패럴린-C, D, N 박막과 두 가지 타입이 혼합된 하이브리드 타입의 화학적, 물리적 패럴린 박막을 제조하였다. 패럴린 증착은 화학기상증착법(chemical vapor deposition: CVD)을 이용하였으며, 열분석을 통해 단일 박막과 하이브리드 타입의 박막에 대한 열적 특성을 비교 분석하였다. 인장 강도와 신장율 그리고 인열력 시험을 통해 박막에 대한 기계적 물성을 알아보았으며, 접촉각과 표면 에너지를 측정하여 박막에 대한 표면 특성을 관찰하였다. 두 가지 타입이 혼합된 하이브리드 타입의 화학적 패럴린 박막은 서로 다른 다이머의 장단점을 상호 보완시켜 줄 수 있으며, 물리적 패럴린 박막은 기재에 코팅되는 면과 반대 면의 박막 특성을 자유롭게 조절할 수 있다.

• 대한화장품학회지
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• 제41권1호
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• pp.1-7
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• 2015

말채나무는 한국의 민간요법으로 사용되던 약재이다. 자외선은 피부의 광손상을 일으키는 것으로 알려져 있다. 본 연구에서는 자외선에 의한 손상된 세포를 회복시키기 위해서 효소처리 된 말채나무잎추출물(CWE)을 사용하였다. 섬유아세포에 UVB를 조사한 후, CWE를 처리하여 세포의 회복을 조사하였다. UVB를 조사한 섬유아세포에는 caspase-3 활성, phospho-p53, ${\gamma}H2AX$, cyclobutane pyrimidine dimers (CPDs) formation, 그리고 DNA fragmentation이 증가하게 된다. 그러나 CWE를 UVB가 조사된 섬유아세포에 12 h 처리하였을 때 caspase-3 활성, phospho-p53, ${\gamma}H2AX$, CPDs formation, 그리고 DNA fragmentation이 감소하였다. 또한 CWE은 인체첩포시험을 통해 인체피부에 자극을 유발하지 않음을 확인하였다. 이러한 결과를 종합할 때 CWE는 자외선에 대한 광보호 효과가 있는 원료로서 가능성을 가지고 있다고 판단된다.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.179-185
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• 2021

Collision-induced dissociation (CID) combined with electrospray ionization mass spectrometry (ESI-MS) was used to obtain structural information on rat islet amyloid polypeptide (rIAPP) monomers (M) and dimers (D) observed in the multiply charged state in the MS spectrum. MS/MS analysis indicated that the rIAPP monomers adopt distinct structures depending on the molecular ion charge state. Peptide bond dissociation between L₂₇ and P₂₈ was observed in the MS/MS spectra of rIAPP monomers, regardless of the monomer molecular ion charge state. MS/MS analysis of the dimers indicated that D⁵⁺ comprised M²⁺ and M³⁺ subunits, and that the peptide bond dissociation process between the L₂₇ and P₂₈ residues of the monomer subunit was also maintained. The observation of (M+ b₂₇)⁴⁺ and (M+ y₁₀)³⁺ fragment ions were deduced to originate from the two different D⁵⁺ complex geometries, the N-terminal and C-terminal interaction geometries, respectively. The fragmentation pattern of the [M_rIAPP + M_hIAPP]⁵⁺ MS/MS spectrum showed that the interaction occurred between the two N-terminal regions of M_rIAPP and M_hIAPP in the heterogeneous dimer (hetero-dimer) D⁵⁺ structure.

• 대한화장품학회지
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• 제48권1호
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• pp.33-38
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• 2022

자외선인 ultraviolet B (UVB)는 피부각질세포의 DNA 잔기에 손상을 준다. 특히, DNA의 pyrimidine 잔기 손상인 cyclobutane pyrimidine dimers (CPD)의 형성은 피부 광노화의 대표적인 지표로 여겨진다. 본 연구에서는 피부 각질세포에서 UVB에 의한 DNA 손상을 완화 시키는 소재로 감초추출물(Glycyrrhiza glabra extract, G. glabra extract)의 효능을 확인하였다. 먼저 피부각질세포에서 UVB 의존적으로 CPD형성이 증가하는 것을 확인하였다. 이후 감초추출물에 의해 UVB 유발 CPD 형성이 유의하게 줄어드는 것을 확인할 수 있었다. 추가로 DNA 손상회복 인자의 mRNA 발현이 감초추출물에 의해 증가하는 것도 확인하였다. 결론적으로 본 연구를 통해 감초추출물의 피부각질세포에서의 DNA 보호 효과를 확인할 수 있었다.