• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.4
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• pp.366-371
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• 2022

Recently many efforts have been made to develop a novel class of non-fullerene electron acceptor materials for high-performance organic solar cells. In this work, anthraquinone derivatives, TMAQ and THAQ, were prepared and their availability as electron acceptor materials for organic solar cells were investigated in terms of optical, thermal, electrochemical properties, and solar cell devices. Compared to TMAQ, a significant bathochromic shift of absorption band was observed for THAQ owing to intramolecular hydrogen-bond-assisted CT interactions. Thanks to the fused aromatic ring structure and benzoquinone unit, both TMAQ and THAQ exhibited a high thermal stability and an efficient electron reduction process. In particular, the intramolecular O-H---O=C hydrogen bond of THAQ plays an important role in improving the thermal stability and electron reduction properties. In the P3HT:acceptor solar cell system, THAQ-based devices had more than ca. 6 times higher power conversion efficiency than TMAQ -based devices. These results serve as a guide for developing high-efficient anthraquinone-based electron acceptor materials.

• Journal of Integrative Natural Science
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• v.8 no.4
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• pp.273-284
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• 2015

Chemoattractant Receptor Homologous molecule expressed on Th2 cells (CRTh2) is a chemoattractant receptor with seven transmembrane helices targeted for inflammatory diseases such as asthma and allergic rhinitis. In this study, pharmacophore based Comparative Molecular Similarity Indices Analysis (CoMSIA) were performed on the series of 2-(2-(benzylthio)-1H-benzo[d]imidazol-1-yl) acetic acids derivatives. Initially, GASP module was used for generation of pharmacophore models using five highly active compounds from the dataset. Among the generated pharmacophores, the best pharmacophore model was selected based on fitness score and was used as template for the alignment of compounds which was used for CoMSIA analysis. The best predictions were obtained utilizing steric, hydrophobic and H-bond acceptor parameters showing a $q^2$=0.559 and $r^2$=0.730. 15 test set compounds was used to investigate the predictive ability of the CoMSIA model. Contour maps suggested that presence of bulky substituents and H-bond acceptor atoms at $5^{th}$ position of benzene ring will increase the activity of the compounds. The results obtained from this study will be useful to design more potent CRTh2 antagonists.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.187-191
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• 2007

Comparative molecular similarity indice analysis (CoMSIA) models on the fungicidal activities of N-phenyl substituents (X) in N-phenyl-O-phenylthionocarbamate derivatives against rice sheath blight (Rhizoctonia solani: RS) and phytophthora blight (Phytophthora capsici: PC) were derived. Also, the characterizations of H-bonds between substrates and ${\beta}-tubulin$ were discussed quantitatively. It was revealed that, from the contour maps of CoMSIA models, the H-bond acceptor field contributed the most highly to fungicidal activity for two fungi in common. It is predicted that the selectivity in the fungicidal activity between two fungi is caused by results from the roles of H-bond donor disfavor functional groups in RS and H-bond acceptor disfavor functional groups in PC when these two groups induced at meta- and para-position on the N-phenyl ring. And also, if the substituents (X) are steric disfavor group, negative charge favor groups are introduced at the metaposition in RS and H-bond acceptor group is introduced at the para-position in PC, the antifungal activity against two fungi will be likely able to be increased.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.171-176
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• 2008

The comparative molecular similarity indices analysis (CoMSIA) models between 3${\beta}$-Hydroxy-12-oleanen-28-oic acid (1-30) analogues as substrate molecule and their inhibitory activities ($pI_{50}$) against protein tyrosine phosphatase (PTP)-1B were derived and discussed quantitatively. Listing in order, the CoMFA>CoMSIA${\geq}$HQSAR>2D-QSAR model, these QSAR models had the better statistical values. The optimized CoMSIA F1 model at grid 3.0${\AA}$ had the best predictability and fitness ($q^2$=0.754 and $r^2$=0.976) by field fit alignment. The order of contribution ratio (%) of CoMSIA fields concerning the inhibitory activities was a H-bond acceptor (48.9%), steric field (25.8%) and hydrophobic field (25.4%), respectively. Therefore, the inhibitory activities of substrate molecules against PTP-1B were dependent upon H-bond acceptor field (A) of $R_4$-group. From the analytical results of CoMSIA contour maps, oleanolic acid derivatives will have better inhibition activities if $R_1$ group has H-bond acceptor disfavor, $R_3$group has steric disfavor and $R_4$ group has steric, hydrophobic, H-bond favor.

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.271-273
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• 1991

Poly (N-vinylcarbazole) was obtained spontaneously by 1,1,2,2-tetracyanocyclopropylstyrene(1) in polar solvents such as dichloromethane and acetonitrile at room temperature. The polymerization reactions were faster in more polar solvent and were not proceeded in less polar solvents such as chloroform and diethyl ether. The formation of poly (N-vinylcarbazole) was explained by bond-forming initiation theory, in which the initiating species are zwitterionic tetramethylene intermediates.

• Journal of the Korean Chemical Society
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• v.18 no.2
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• pp.85-96
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• 1974

Extended H ckel Theory and CNDO/2 MO calculation methods have been applied to $C_6H_5YCH_2Cl$(Y = None, -$CH_2$-, -O-, -S-, -CO-, -$SO_2$-). It has been shown that charge distributions in molecules are mainly controlled by the migration of valence inactive electron, giving the order of ${\sigma}$-acceptor and ${\pi}$-donor effects -O- > -S- > -$CH_2$- > -$SO_2$-. The -CO- group exceptionally acts as ${\sigma}$-donor and ${\pi}$-acceptor. It was also predicted that, $S_N2$ reactivities of C$C_6H_5YCH_2Cl$ would be in the order of -O-${\thickapprox}$-CO- >>-S-${\thickapprox}$None > -$CH_2$-, neglecting solvent effect. From the results of our studies, we conclude that the structural factors influencing 의 $S_N$ reactivities will be: (1) positive charge developments on reaction center carbon atom (2) energy level of ${\sigma}$-antibonding unoccupied MO with respect to C-Cl bond. (3) ${\sigma}$-antibonding strength of C-Cl bond at that level.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.613-617
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• 2009

3D-QSARs for the inhibition activities against protox by herbicidal 2-N-phenylisoindolin-1-one derivatives were studied quantitatively using CoMFA and CoMSIA methods. The result of the statistical quality of optimized CoMSIA model 2 ($FF:\;{r^2}_{cv.};\;0.973\;&\;{r^2}_{ncv.};\;0.612$) was higher than that of CoMFA model 1 ($AF:\;{r^2}_{cv.};\;0.414\;&\;{r^2}_{ncv.};\;0.909$). Also, the relative contribution of the optimized CoMSIA model 2 showed the steric (24.6%), electrostatic (31.0%), hydrophobic (ClogP, 23.4%) and H-bond acceptor field (21.0%), respectively. From the results of the contour maps, the protox inhibition activities are expected to increase when steric favor and H-bond acceptor favor groups are substituted on $R_2$ position and positive favor group are substituted on $C_2,\;C_3,\;and\;C_5$ atom in phenyl ring of $R_2$ position. And the inhibition activities are expected to increase when hydrophobic favor group is substituted on $C_1,\;C_3$ atom in phenyl ring of $R_2$ position and $C_1$ atom of $R_2$ position and hydrophilic favor groups are substituted on $C_4$ atom in phenyl ring of $R_1$ position and the terminal group of $R_1$ position.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.379-385
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• 2007

Receptor-oriented pharmacophore-based in silico screening is a powerful tool for rapidly screening large number of compounds for interactions with a given protein. Inhibition of the enzyme catechol-Omethyltransferase (COMT) offers a novel possibility for treating Parkinson's disease. Bisubstrate inhibitors of COMT containing the adenine of S-adenosylmethionine (SAM) and a catechol moiety are a new class of potent and selective inhibitor. In the present study, we used receptor-oriented pharmacophore-based in silico screening to examine the interactions between the active site of human COMT and bisubstrate inhibitors. We generated 20 pharmacophore maps, of which 4 maps reproduced the docking model of hCOMT and a bisubstrate inhibitor. Only one of these four, pharmacophore map I, effectively described the common features of a series of bisubstrate inhibitors. Pharmacophore map I consisted of one hydrogen bond acceptor (to Mg2+), three hydrogen bond donors (to Glu199, Glu90, and Gln120), and one hydrophobic feature (an active site region surrounded by several aromatic and hydrophobic residues). This map represented the most essential pharmacophore for explaining interactions between hCOMT and a bisubstrate inhibitor. These results revealed a pharmacophore that should help in the development of new drugs for treating Parkinson's disease.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.11a
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• pp.274-275
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• 2004

The majority of dyes belong to the chromophoric class known as donor-acceptor systems, the essential structural feature of such systems being the presence of one or more electron donating groups conjugated to one or more electron withdrawing groups via an unsaturated bridge. The indigo molecule may be formally divided into two identical electron donor/acceptor subsystems, each containing an add number of pi electrons, two subsystems being joined by carbon-carbon double bond. Indigoid type dyes which show a strong colour change on protonation or dissociation have many potential functional applications, for example as analytical pH indicators, solvent polarity indicators, and in various imaging and reprographic systems.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1241-1248
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• 2011

Three dimensional quantitative structure-activity relationships (3D-QSARs) between new thiosemicarbazone analogues (1-31) as a substrate molecule and their inhibitory activity against tyrosinase as a receptor were performed and discussed quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods. According to the optimized CoMSIA 2 model obtained from the above procedure, inhibitory activities were mainly dependent upon H-bond acceptor favored field (36.5%) of substrate molecules. The optimized CoMSIA 2 model, with the sensitivity of the perturbation and the prediction, produced by a progressive scrambling analysis was not dependent on chance correlation. From molecular docking studies, it is supposed that the inhibitory activation of the substrate molecules against tyrosinase (PDB code: 1WX2) would not take place via uncompetitive inhibition forming a chelate between copper atoms in the active site of tyrosinase and thiosemicarbazone moieties of the substrate molecules, but via competitive inhibition based on H-bonding.