• Journal of the Korean Chemical Society
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• v.28 no.2
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• pp.79-85
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• 1984

The ionic association constant(K) of 2,4,6, N-tetramethyl pyridinium iodide (TeMPI) in 95 volume percentage ethanol-water mixture were determined by a modified UV and conductance method at $25^{\circ}C$ to $50^{\circ}C$ under 1 to 2,000 bars. The K values increase with increasing pressure and have maximum value at $40^{\circ}C$. The partial molar volume hange (${\Delta}V$) has relatively small negative value and the absolute values of ${\Delta}$ are minimum at $40^{\circ}C$. The ion size parameter(a) of TeMPI have maximum value at $40^{\circ}C$. {\Delta}H^{\circ}$ values are zero, positive and negative at 40^{\circ}C$, $25^{\circ}C$ and $50^{\circ}C$ respectively. Other thermodynamic parameters such as the changes of standard entropy ({\Delta}S^{\circ}$) and free energy {\Delta}G^{\circ}$ were evaluated. From these experimental results, we came to conclusion that TeMPI is stabilized by the elevation of pressure and that of temperature below $40^{\circ}C$ but weakly dimerized at $40^{\circ}C$ because of the intermolecular hydrophobic interaction of eight methyl groups of two molecules. And it thermally decomposed above $50^{\circ}C$.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.412-422
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• 2002

The use of biochemical markers of bone turnover may be particular interest in the investigation of bone disorders with osteoporosis. Serum osteocalcin(OC), total alkaline phosphatase and procollagen C, reflecting bone formation, and urinary pyridinium cross-links excretion, reflecting bone reabsorption have been measured in hyperthyroidism, postmenopause women, after testosterone supplementation, androgen, testosterone and estrogen deficiency, bone mineral density degree, age duration. Bone marks which is reflect to metabolic bone disorders are biochemical indices method to measure enzyme activity about bone formation, bone absorption and bone components in blood or urine. Bone metabolism biochemical marks are correlated with osteophorotic agents and also represent significantly different between bone mineral density and bone biochemical marks. Therefore if we develope and use bone metabolism marks which have higher sensitivity and specificity in bone formation and bone absorption, I think that these bone biochemical marks can have utility in the clinical application to predict osteoporosis risk group, bone loss, bone fracture and response degree to treatment of osteoporosis risk groups.

• Textile Coloration and Finishing
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• v.9 no.3
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• pp.42-49
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• 1997

In order to study the dyeability of reactive dyes fixable at neutral pH, three reactive dyes(DYE-NC, DYE-PC, and DYE-LC) were prepared by the reaction of Cibacron Brilliant Red 3B-A with nicotinic acid, pyridine, and lutidine, respectively. FT-IR and UV/Vis spectrophometry were used to identify the dyes prepared. While the maximum absorption wavelength (&{\lambda}_{max}&) of Cibacron Brilliant Red 3B-A was 515nm, the &{\lambda}_{max}& of DYE-NC, DYE-PC, and DYE-LC were 522nm, 525nm, and 536nm, respectively. The &{\lambda}_{max}& was shifted to the longer wavelength by introducing the electron donating groups to the pyridine ring of Cibacron Brilliant Red 3B-A. All of the reactive dyes synthesized showed good exhaustion and fixation property to cotton fabric at higher temperature and neutral pH condition. It was regarded that the quaternary pyridinium ion functionated as the leaving group instead of the chloride ion. Among them, DYE-NC showed the best dyeability at the above condition. It was considered that the electron withdrawing carboxylic acid group in nicotinic acid enhanced the cationic property of nitrogn in pyridine ring, resulting the good reactivity with OH group in cellulose.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.469-476
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• 2008

The synthesis of cyclic carbonate from butyl glycidyl ether (BGE) and carbon dioxide was performed in the presence of three different types of ionic liquid : quarternary ammonium salt, alkyl pyridinium salt, and alkylimidazolium salt. Ionic liquids of different alkyl groups ($C_3$, $C_4$, $C_6$ and $C_8$) and anions ($Cl^-$, $Br^-$ and $I^-$) were used for the reaction which was carried out in a batch autoclave reactor at $60{\sim}120^{\circ}C$. The catalytic activity was increased with increasing alkyl chain length in the order of $C_3$ < $C_4$ < $C_6$. But the ionic liquid with longer alkyl chain length ($C_8$) decreased the conversion of BGE because it is too bulky to form an intermediate with BGE. For the counter anion of the ionic liquid catalysts, the BGE conversion decreased in the order $Cl^-$ > $Br^-$ > $I^-$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.324-330
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• 2004

The purpose of this study was to investigate the effects of Porphyra tenera (PT) extracts on formation of collagen cross-link in ovariectomized rats. From day 3 until 42 after the ovariectomy, Sprague-Dawley female rats were randomly assigned to the following groups : sham-operated rats (Sham), ovariectomized control rats (OVX-control), ovariectomized rats supplemented with PT at 50 mg/kg bw/day (OVX-PT5O), 200 mg/kgbw/day (OVX-PT200). The PT ethanol extracts were orally administrated 1 mL per day. Body weight gain, food intake and food efficiency ratio were significantly different among the groups. The change of collagen content was studied in lung, bone, cartilage and skin of ovariectomized rats. The effects of PT extracts on the amount of collagen were examined by measuring the hydroxyproline, which is a specific amino acid existing in collagen. Pyridinoline is pyridinium cross-link formed in the mature form of collagen from lysine and hydroxylysine residues. Pyridinoline content was analyzed by HPLC. Pyridinoline content in bone collagen was decreased by ovariectomy but supplementation with the PT extracts was similarly increased to Sham. These results suggest that the PT supplementation could decrease bone loss in postmenopausal women.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2203-2208
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• 2007

Three possible binding modes of cationic meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) to d[(GCATATATGC)2] duplex were investigated by the molecular dynamics (MD) simulation. Among the three binding modes namely, “along the groove”, “across the groove” and “face on the groove”, the “across the groove” model exhibited the largest negative binding free energy and the DNA backbone remained as the B form. In this model, the molecular plain of the TMPyP tilts 45o with respect to the DNA helix axis and is largely exposed to the solvent. TMPyP was stabilized mainly by the interaction between the positively charged neighboring pyridinium moieties of TMPyP and negatively charged phosphate groups of DNA. The result obtained in this work by MD and the report (Jin, B. et al., J. Am. Chem. Soc. 2005, 127, 2417.) that the spectral properties of poly[d(A-T)2] bound TMPyP in the presence and absence of the minor groove binding drug 4',6- diamidino-2-phenylindole are similar, we propose that TMPyP bind across the minor groove of the AT rich- DNA.

• Journal of Life Science
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• v.18 no.11
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• pp.1578-1583
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• 2008

The purpose of this study was to investigate the effects of sea tangle (ST) extracts on formation of collagen and collagen cross-link in ovariectomized rats. From day 3 until 42 after the ovariectomy, Sprague-Dawley female rats were randomly assigned to the following groups: sham-operated rats(Sham), ovariectomized control rats (OVX-control), ovariectomized rats supplemented with ST at 50 mg/kg bw/day (OVX-ST50), 200 mg/kg bw/day (OVX-ST200). The ethanol extraxcr of ST was orally administrated at 1 ml/day. The change of collagen content was investigated in bone, cartilage and skin of ovariectomized rats. Effects of ST extract on the amount of collagen was examined by measuring the hydroxyproline, which is a specific amino acid existing in collagen. The ovariectomy resulted in a decrease in the levels of collagen content in bone and cartilage tissues. However, the supplementation with the sea tangle extract prevented the decrease in the collagen level in bone and cartilage tissues. Pyridinoline is pyridinium cross-link formed in the mature form of collagen from lysine and hydroxylysine residues. Although the pyridinoline content in bone collagen declined after ovariectomy, it was recovered to a normal level of Sham group by the supplementation with the ST extracts. In addition, the deoxypyridinoline content in bone collagen, which was reduced after ovariectomy was enhanced to normal level by the supplementation with the ST extract. These results was consistent with the conclusions based on estrogenic activities of ST.