• Archives of Pharmacal Research
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• v.22 no.4
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• pp.384-390
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• 1999

Thirty-four glutathione conjugates of 5,8-dimethoxy-1,4-naphthoquinones (DMNQ) were synthesized and their structure was determined. The yield of GSH conjugate was dependent on size of alkyl group; the longer the size of alkyl group was, the lower was the yield. It was also found that the length of alkyl side chain influenced the chemical shift of quinonoid protons; the quinonoid protons of 2-glutathionyl DMNQ derivatives with R=H to propyl, 6.51-6.59 ppm vs. other ones with R=butyl to heptyl, 6.64-6.68 ppm. this was explained to be due to a folding effect of longer alkyl group. Glutathione (GSH) reacted with DMNQ derivative first to form a 1,4-adduct (2- or 3-glutathionyl-1,4-dihydroxy-5,8-dimethoxynaphthalenes) and then the adduct was autooxidized to 2- or 3-glutathionyl-DMNQ derivatives. Moreover, GSH reduced DMNQ derivatives to their hydrogenated products. It was suggested that such an organic reaction might play an important role for a study of metabolism or toxicity of DMNQ derivative sin the living cells.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.103-110
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• 2008

To develop the third generation herbicidal cyclic imide (Cyl) derivatives, the new 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-thiourea derivatives were synthesized and measured their herbicidal activities ($pI_{50}$) in vivo (preemergence) against rice plant (Orysa Sativa) and barnyard grass (Echinochlor crus-galli). The synthetic yields (%) of aryl derivatives (21-40) in general was higher than that of alkyl derivatives (1-20). In case of alkyl derivatives, the synthetic yield depended on the structural forms of alkyl amine groups. From the results of correlation analysis between herbicidal activities and substituents, the compound 8 and 24 showed the highest herbicidal activity against the shoot and root of barnyard grass. Especially, the compounds 11 and 6 showed the selective herbicidal activities between rice plant and barnyard grass.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.248.2-248.2
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• 2003

The 18 ureidoceramide derivatives had been investigated for their cytotoxic activity against HT-29 colon cancer, Caki-2 renal cancer, A549 lung cancer, PC-3 prostate cancer, HL -60 leukemia cell using MTT assay. Cytotoxic activity was strongly influenced by the substituted alkyl chain length and the optimal alkyl chain length for cytotoxicity was C9-C12. (omitted)

• Journal of Pharmaceutical Investigation
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• v.8 no.3
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• pp.11-15
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• 1978

The contamination concentrations of the alkyl benzene sulfonate (ABS) pollution in the Han river were investigated at 3 sites from July through september, 1977. The samples were taken on the upper, the middle, and the lower Han river and 5points of each part, respectively. The contamination concentrations of ABS pollution in the river were 0.012 p.p.m of the upper site, 0.206 p.p.m of the middle site, and 0.486 p.p.m of the lower site in average, respectively. Consequently, the contamination concentrations of ABS pollution in the Han river were the highest at the lower site, where is between second Han river bridge and Nan Ji island.

• Journal of Integrative Natural Science
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• v.1 no.2
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• pp.76-78
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• 2008

A series of the long-chain iron(II) alkylsulfonate hydrates were synthesized via self-assembly of surfactant alkyl chains in aqueous medium. Reaction of iron(II) salts with n-alkylsulfonate yields lamellar $Fe(CnH2n+1SO3)2{\cdot}4H_2O$. These compounds show a layered structure, as determined by XRD, consisting of alternating organic alkylsulfonate layers and inorganic iron(II) hydrate layers, with interlayer distances of upto 3.2 nm. This lamellar structure may be attributed to the amphiphilic nature of the surfactants, mediating the coordination and H-bionding interactions, and the hydrophobic alkyl chains. An alkyl chain packing of present system are differ from those of similar Cu(II) series, which are attributed from the size of hydrated metal(II) ions.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.259-265
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• 1992

Cyclic voltammetric behavior of symmetric (dimethyl, diheptyl, dioctyl, dibenzyl) and asymmetric (methyloctyl, methyldodecyl, methylbenzyl) viologens was investigated in homogeneous aqueous solution and sodium dodecyl sulfate (SDS) micellar media. In SDS-free 0.1 M NaCl solutions, the reduction potential is less negative as the chain length of alkyl substituent is longer. This is due to the stabilization of the reduced cationic radical and neutral form of viologen by adsorption on electrode surface. The adsorbed species show the "aging-effect". With the exceptions of methyldodecyl viologen and methylbenzyl viologen, the viologens show strong tendency of conproportionation reaction between viologen dications and neutral forms. In cases of methyldodecyl viologen and methylbenzyl viologen, the conproportionation reaction is kinetically disfavored, though it is thermodynamically favorable. SDS micelles dissolve the adsorbed species and the viologens exhibit two reversible redox processes in SDS micellar solutions. The reduction potentials of viologens in SDS micellar solutions depend little on the length of alkyl chain. Benzyl-substituted viologens are more easily reduced than the alkyl substituted viologens, presumably due to electron-withdrawing character of benzyl group.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.285-289
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• 1992

Enantiomeric separation of underivatized amino acids using N-alkyl-L-proline (octyl, dodecyl or hexadecyl) coated HPLC has been accomplished. The anchoring N-alkyl groups of L-proline provides a permanent adsorption of there solving chiral agent on the hydrophobic interface layer of a reversed phase. The factors controlling retention and enantioselectivity such as the Cu(II) concentration, pH of the eluent, the type and concentration of organic modifier in the hydroorganic eluent, and extent of coating were examined. The elution orders between D- and L-amino acids were consistent, L-forms eluting first, except histidine and asparagine. The extremely high enantioselectivity $(\alpha$ upto 13 for proline) is observed. The retention mechanism for the chiral separation can be illustrated by a complexation and hydrophobic interaction.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.404-406
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• 1998

Analysis for the imidazoline type cationic surfactants was performed by the gas chromatography(GC) and high performance liquid chromatography(HPLC). The composition of the alkyl chain distribution was investigated by GC after base/Acid hydrolysis of the imidazoline ring. The distribution of total alkyl chain was separated clearly by a Bondclone C18/NOVA-Pak C18 HPLC column using 50% acetonitrile in methanol containing 0.1M sodium perchlorate as a mobile phase. Alkyl chain distribution and average molecular weight of imidazoline type cationic surfactants were obtained based on these analytical methods. The agreement of results from GC and HPLC was good. The detection limit of imidazoline by HPLC method was 10ng without pretreatment.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.377-383
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• 2003

Physicochemical properties of a series of PC monolayers with different alkyl chains (C24, C20, C16, and C8), at the air/water interface were investigated. The surface pressure is influenced mainly by the hydrophobicity of the PCs, which is confirmed by the curve shape and the on-set value of π-A isotherms at the air/water interface by increasing the number of alkyl chain. The on-set values of surface pressure were 125 Ų/molecule for DOPC(C8), 87 Ų/molecule for DPPC(C16), 75 Ų/molecule for DAPC(C20), and 55 Ų/molecule for DLPC(C24), respectively. The orientations of alkyl chains at the air/water interface are closely connected with the rigidity of the monolayers, and it was confirmed by the tendency of monolayer thickness in ellipsometry data. The temperature dependence of a series of PCs shows that the surface pressure decreases by increasing temperature, because the longer the alkyl chain length, the larger the hydrophobic interaction in surface pressure. The temperature effects and the conformational changes of unsaturated and saturated PCs were confirmed by the computer simulation study of the cis-trans transition with POPC and DPPC(C16). The cistrans conformational energy difference of POPC is 62.06 kcal/mol and that of DPPC(C16) is 6.75 kcal/mol. Due to the high conformational energy barrier of POPC, phase transition of POPC is limited in comparison with DPPC(C16).

• YAKHAK HOEJI
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• v.28 no.4
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• pp.197-206
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• 1984

The derivatives of N-(alkylcarbamoyl) amino acid methyl ester, N-(2-chloroethylcarbamoyl)-glycine methyl ester (7a), -valine methyl ester (8a), -phenylalanine methyl ester (9a), N-(N'-methylcarbamoyl)-glycine methyl ester (7b), -valine methyl ester (8b), and-phenylalanine methyl ester (9b), were prepared by reacting the corresponding free amino acid methyl ester (glycine-, valine-, phenylalanine-methyl ester) with isocyanate (R-N=C=O${\cdot};R=Cl-CH_2-CH_2-or\; CH_3-)$. The prepared N-(alkylcarbamoyl) amino acid methyl esters (7,8,9) were treated with $NaNO_2$/98% HCOOH in order to obtain their nitrosoated products, N-(alkyl-N'-nitrosocarbmoyl)amino acid methyl ester. The compound (7,8,9) gave N-(2-chloroethyl-N'-nitrosocarbamoyl)-valine methyl ester (14a),-phenylalanine methyl ester (15a), N-(N'-alkyl-N'-nitrosocarbamoyl)-glycine methyl ester (13b),-valine methyl ester. (14b), and-phenylalanine methyl ester (15b) respectively under the nitrosoation. On the other hand, N-(2-chloroethylcarbamoyl) glycine methyl ester produced N-(2-chloroethylcarbamoyl)-N-nitrosoglycine methyl ester (13a). The inhibitory activity of the prepared N-(alkylcarbamoyl) amino acid methyl ester (7,8,9) and N-(alkyl-N'-nitrosocarbamoyl) amino acid methyl ester (13,14,15) towards the growth of L1210 murine leukemia cells were examined. Among them the compound (14a) and (15a) exhibit excellent activity having $ED_{50}\; to\;be\;1.5{\mu}g/ml\;and\;3.0{\mu}g/ml respectively.