• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3181-3187
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• 2014

A series of 3,4-dihydroquinazoline derivatives with anti-cancer activities against human colon cancer HT-29 cell were subjected to three-dimensional quantitative structure-activity relationship (3D-QSAR) studies using the comparative molecular similarity indices analysis (CoMSIA) approaches. The most potent compound, BK10001 was used to align the molecules. As a result, the best prediction was obtained with CoMSIA combined electrostatic, hydrophobic, and hydrogen-bond acceptor fields ($q^2=0.648$, $r^2=0.882$). This model was validated by an external test set of six compounds giving satisfactory predictive $r^2$ values of 0.879. This model would guide the design of potent 3,4-dihydroquinazoline derivatives as anti-cancer agent for the treatment of human colon cancer.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.19-22
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• 2001

The effects of pH on the sequential sorption/desorption of chlorinated phenols (2-chlorophenol, 2.4-dichlorophenol and 2,4,5-trichlorophenol) in HDTMA-montmorillonite were investigated by maintaining pH 4.85 or 9.15 in the sequential batch sorption and desorption experiments. The chlorinated phenols are hydrophobic ionizable orginic compounds; they can exist as either neutral (pH << pKa) or anionic (pH >> pKa) forms. Among the tested chlorinated phenols, 2,4,5-trichlorophenol showed the highest sorption affinity at pH 4.85 as expected by the $K_{ow}$ . Neutral speciation at pH 4.85 exhibited higher sorption affinity than anionic speciation at pH 9.15. Our results indicates that desorption of chlorinated phenols is strongly dependent on pH of the aqueous phase. Freundlich model was used to analyze the single-solute sorption/desorption results. The ideal adsorbed solution theory(IAST) was employed to predict the hi-solute sorption/desorption equilibria.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2097-2108
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• 2014

Chemical feature based quantitative pharmacophore models were generated using the HypoGen module implemented in DS2.5. The best hypothesis, Hypo1, which was characterized by the highest correlation coefficient (0.96), the highest cost difference (61.60) and the lowest RMSD (0.74), consisted of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic and one ring aromatic. The reliability of Hypo1 was validated on the basis of cost analysis, test set, Fischer's randomization method and GH test method. The validated Hypo1 was used as a 3D search query to identify novel inhibitors. The screened molecules were further refined by employing ADMET, docking studies and visual inspection. Three compounds with novel scaffolds were selected as the most promising candidates for the designing of Mcl-1 antagonists. Finally, a 10 ns molecular dynamics simulation was carried out on the complex of receptor and the retrieved ligand to demonstrate that the binding mode was stable during the MD simulation.

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.205-210
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• 2005

There has been a growing interest in NF membrane for drinking water treatment, because it can remove simultaneously both hardness and hazardous micro pollutants such as pesticides and THM precursors. In this work, a hollow fiber NF membrane known as a composite membrane was employed for the rejection properties of both hydrophilic solutes and micro organic pollutants, where the former was used to evaluate the molecular sieving effect of this membrane and the latter was employed for the investigation of solute-membrane interaction as hydrophobic materials. This membrane effectively rejected the hydrophilic solutes and the permeation of them was mainly controlled by the molecular sieving effects such as molecular weight and molecular width. In the case of all micro organic pollutants, the rejections were varied from 42.2% for Simazine to 91.6% for Malathion, and the parameters related to the steric hindrance could significantly play an important role in the rejection. In the batch type adsorption experiments, all micro organic pollutants were entrapped mildly on the membrane in spite of lower degree compared with that of aromatic compounds, and they were correlated with log K.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.21-26
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• 1996

Commercially available Chines oriental lacquer was treated to get two fractions, hexane soluble fraction and hexane insoluble fraction. Hexane soluble fraction was subjected to thermal curing process. Films obtained from the lacquer under normal conditions and obtained from thermal curing were compared. The compounds in hexane soluble fraction were copolymerized with 1,6-diisocyanohexane, and toluendiisocyanate(TDI). Films obtained by thermal curing were highly brittle and hydrophobic while the films obtained under normal conditions were hydrophilic. Curing reaction did not occur when oxygen was not available.Some of the major component in the lacquer was isolated by HPLC and UV spectrum of each compound was recorded.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.146-150
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• 2010

A distinguished class of hydrophobic ionic liquids bearing a Br${\o}$nsted acidic character derived from amide-like compounds were prepared by a neutralization reaction of N,N-diethylformamide, N,N-dibutylformamide, 1-formylpiperidine, and $\varepsilon$-caprolactam with trifluoroacetic acid and physical absorptions of $CO_2$ in these ionic liquids were demonstrated and evaluated. $CO_2$ solubilities in these ionic liquids were influenced by the molecular structure of the cation and were apparently increased with the molar volume. Comparison based on a volume unit reveals that $CO_2$ solubilities in these liquids are relatively higher than those in imidazolium-based ionic liquids. Henry's coefficients calculated from low-pressure solubility tests at 313 to 333 K were used to derive the thermodynamics quantities. Enthalpy and entropy of solvation may share equal contributions in solubility.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.97-98
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• 1998

1. Introduction : Polypropylene(PP) membrane is widely used in the field of microfiltration and ultrafiltration. However, the hydrophobicity of PP causes the adsorption of hydrophobic and amphoteric solutes in the feed. Surface modification techniques of membrane through the treatment of hydrophilizing agents, coating of hydrophilic compounds, UV, plasma and high energy irradiation, etc. can have a great effect on propensities to prevent the protein from staining membranes. Among them, the modification to hydophilize membrane surface using UV is very simple and effective. Recently many studies for more effective surface modification have been conducted. Iwata et al. prepared membranes by grafting polyethylene glycol diacrylate macromer(PEGDA) onto polysulfone with plasma using a glow discharge reactor which prevent the oil from staining the membrane. The primary mechanism contributing to the membranes is preventing the oil from directly contacting the surface of the membrane as the PEGDA chains dissolved into emulsion. To evaluate their feasibility for use as a anti-fouling separation membrane, we prepared hydrophilic membranes by UV irradiation method and investigated their characteristics.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.3
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• pp.237-243
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• 2013

B13 is a ceramide analogue and apoptosis inducer with potent cytotoxic activity. A series of arylpropyl sulfonamide analogues of B13 were evaluated for their cytotoxicity using MTT assays in prostate cancer PC-3 and leukemia HL-60 cell lines. Some compounds (4, 9, 13, 14, 15, and 20) showed stronger activities than B13 in both tumor cell lines, and compound (15) gave the most potent activity with $IC_{50}$ values of 29.2 and 20.7 ${\mu}M$, for PC-3and HL-60 cells, respectively. Three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis was performed to build highly reliable and predictive CoMSIA models with cross-validated $q^2$ values of 0.816 and 0.702, respectively. Our results suggest that long alkyl chains and a 1R, 2R configuration of the propyl group are important for the cytotoxic activities of arylpropyl sulfonamides. Moreover, the introduction of small hydrophobic groups in the phenyl ring and sulfonamide group could increase biological activity.

• Environmental Analysis Health and Toxicology
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• v.21 no.3 s.54
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• pp.255-266
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• 2006

Soil organic matter (OM) is well documented for its capacity to retain persistent organic pollutants (POPs) and thus is important in dictating the environmental partitioning of POPs between media such as air, water, and soil. Black carbon (BC) is a small component of OM and exhibitt a 10$\sim$100 times greater sorption capacity of POPs than humified OM. Furthermore, due to the inherent long environmental life time of BC, a result of its resistance to physical and biological degradation, POPs can continue to accumulate in BC over a long period of time. The unique properties of BC have been of particular interest over the last 30 years and have resulted in broad research being conducted into its effects of POP cycling in atmospheric, oceanographic and soil matrices. The results of such studies have proved valuable In providing new research initiatives into the role of BC in the cycling of hydrophobic organic compounds (HOCs) as well as giving further insight into the long range atmospheric transport (LRAT) potential and subsequent risk assessment criteria for persistent organic pollutants (POPs). In this report, we introduce a novel study examining the relationships between BC and OM with respect to their POP sorption capacity and discuss the role of BC in influencing the environmental regulation of organic pollutants.

• KSBB Journal
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• v.11 no.6
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• pp.726-732
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• 1996

Selective adsorption of plant metabolites from a polar dilute solution onto a polycarboxyl ester sorbent (XAD-7) was investigated. Experimental results demonstrated that neutral resins could selectively concentrate specific flavonoids from dilute aqueous mixtures. Adsorption was dependent on the pH of medium, dosage of the resins and medium composition. Especially the medium composition was a key factor for the selective adsorption and it was found that the selective adsorption was dependent on specific sorbent-sorbate-medium characteristics. Under the optimum condition, selectivity increased up to 85% and the yield of recovery was approached to 98%. It was also found that XAD-7 adsorbed flavonoids in the order of hydrophobicity.