• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.650-655
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• 2011

Three new peptide analogs 5a-c were obtained through coupling of 5-Amino benzimidazoles 2a-c with L-phenylalanine. For the purpose ${\alpha}$-amino group was blocked with phthalic anhydride and activation of ${\alpha}$-carboxy group of phenylalanine was carried out by preparing phthaloyl-L-phenylalanyl chloride 4. After developing a successful peptide linkage, the phthaloyl group was removed by treating 5a-c with hydrazine hydrate to get free peptides 6a-c, purified through a column of Amberlite (IR-4B). All of these compounds 2a-c and 5,6a-c have been characterized on the basis of their IR, 1H NMR and EIMS analyses. Antibacterial activity of these compounds is also been reported.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2395-2406
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• 1992

Laminar natural convection heat transfer from a hot body in a square enclosure has been studied for various center positions of a hot body at Grashof number Gr=1.5$\times$10／sup 5／, Prandtl number Pr=0.71 and dimensionless thermal conductivity K／sub s／／K／sub f／= 14710. In case of vertical cold walls, the natural convection at the dimensionless center position of a hot body, X／sub c／Y／sub c／=0.2, 0.5 shows the most strong and at X／sub c／, Y／sub c／=0.5, 0.8 the most weak. In case of horizontal cold walls, the natural convection at the dimensionless center position of a hot body ; X／sub c／ Y／sub c／=0.5, 0.2 shows the most strong and at X／sub c／, Y／sub c／=0.2, 0.5 the most weak.

• Journal of the Korean Applied Science and Technology
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• v.14 no.1
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• pp.61-76
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• 1997

Triacylglycerols of the seeds of Ginkgo biloba have been resolved by high-performace liquid chromatography(HPLC} in the silver-ion and reverse-phase modes. The fatty acids were identified by a combination of capillary gas chromatography and gas-chromatography /mass spectrometry as the methyl and /or picolinyl ester. The main components are $C_{18:2{\omega}6}$(39.0mol%), $C_{18:1{\omega}7}$(asclepic acid 21.5mol%), and $C_{18:1{\omega}9}$(oleic acid, 13.8mol%). Considerable amounts of unusual acid such as $C_{20:3{\Delta}^{5,11,14}$ (5.7mol%), $C_{18:2{\Delta}^{5,9}$(2.8mol%), and $C_{18:3}{\Delta}^{5,9,12}$(1.6mol%), were checked. In addition, an anteiso-branched fatty acid, 14-methylhexadecanoic acid, was also present as a minor component(0.9 mol%). The triacylglycerols were separated into 17 fractions by reverse-phase HPLC, and the fractionation was achieved according to the partition numnber(PN) in which a ${\Delta}^5$-non methylene interrupted double bond($^5$-NMDB) showed different behaviour from a methylene interrupted double bond in a molecule with a given cahinlength. Silver-ion HPLC exhibited excellent resolution in which fractions(23 fractions) were resolved on the basis of the number and configuration of double bonds. In this instance, the strength of interaction of a ${\Delta}^5$-NMDB system with silver ions seemed to be weaker than a methylene interrupted double bond system. The principal triacylglycerol species are as follows ; $(C_{18:2{\omega}6)2}/C_{18:1{\omega}7}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$, $C_{16:1{\omega}7}/C_{18:1{\omega}9}/C_{20:3}{\Delta}^{5,11,14}$, $C_{16:1{\omega}7}/C_{18:1{\omega}7}/C_{20:3}{\Delta}^{5,11,14}$, $C_{18:1{\omega}9}/C_{18:1{\omega}7}/C_{18:2{\omega}6}$, $C_{18:1{\omega}9}/C_{18:2}{\Delta}^{5,5}/C_{20:3}{\Delta}^{5,11,14}$, $(C_{18:1{\omega}7)2}/C_{18:2{\omega}6}$ and $(C_{18:1{\omega}9)2}/C_{18:2{\omega}6}$, while simple triacylglycerols without $C_{18:2{\omega}6})_3$ were not present. Stereospecific analysis showed that fatty acids with ${\Delta}^5$-NMDB system and saturated chains were predominantly located at the site of sn-3 carbon of glycerol backbones. It is evident that there is asymmetry in the distribution of fatty acids in the TG molecules of Ginkgo nut oils.

• Bulletin of the Korean Chemical Society
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• v.18 no.4
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• pp.402-405
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• 1997

Olefinic and cyclopropyl group substituted arenes (C6H5Y) react with [Cp*Ir(CH3COCH3)3]A2 (A=ClO4-, OTf-) to give η6-arene complexes, [Cp*Ir(η6-C6H5Y)]2+ (1a: Y=-CH=CH2 (a),-CH=CHCH3 (b),-C(CH3)=CH2 (c),-CH-CH2-CH2 (d)). Complex 1b-1d are readily converted into η3-allyl complexes, [Cp*(CH3CN)Ir(η3-CH(C6H5)CHCH2)]+ (2a) and [Cp*(CH3CN)Ir(η3-CH2(C6H5)CH2)]+ (2b), in the presence of Na2CO3 in CH3CN. The η6-styrene complex, 1a reacts with NaBH4 to give η5-cyclohexadienyl complex, [Cp*Ir(η5-C6H6-CH=CH2)]+ (3), while with H2 it gives η6-ethylbenzene complex [Cp*Ir(η6-C6H5CH2CH3)]2+ (4). Complex 1a and 1c react with HCl to give [Cp*Ir(η6-C6H5CH2CH2Cl)]2+ (5a) and [Cp*Ir(η6-C6H5CH(CH3)CH2Cl]2+ (5b), respectively.

• YAKHAK HOEJI
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• v.48 no.2
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• pp.135-140
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• 2004

For the development of new COX-2 inhibitors, 1,5-diarylhydantoins 5a∼5c and 1,5-diaryl-2-thiohydantoin 6a∼6c were synthesized from commercially available phenylacetic acids through esterification, bromination, C-N bond formation and cyclization. Esters 2a∼c were efficiently synthesized from the starting materials 1a∼c by refluxing in absolute methanol for 3 hours with catalytic concentrated sulfuric acid. Bromination of 2a∼c was carried out with use of N-bomosuccinimide at rt in dichloromethane. The bromine of 3a∼c was substituted with aniline in ethanol or N,N-dimethylformamide to provide 4a∼c. Hydantoins and 2-thiohydantoins were synthesized from 4a∼c by treatment of potassium isocyanate or potassium thiocyanate in dil-ethanol with triethylamine.

• Bulletin of the Korean Chemical Society
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• v.23 no.7
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• pp.953-956
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• 2002

Excess molar volumes (Vm E ) of binary liquid mixtures: xC6H5CH3 + (1-x1)CH3CN or + (1-x1)C6H5NO2, or + (1-x1)C2H5NO2 have been determined as a function of mole fraction of C6H5CH3 (x) at a temperature of 303.15 K over a entire range of composition. The densities of the binary liquid mixtures were determined by pycnometrically. The VmE values of the mixtures have been found to be negative over the whole composition in order of C6H5CH3 + C6H5NO2, < C6H5CH3 + CH3CN, and < C6H5CH3 + C2H5NO2. The negative magnitude of VmE suggests the presence of intermolecular interaction in the three binary liquid mixtures.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.417-424
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• 1996

The present study was done to examine the involvement of protein kinase C and protein tyrosine kinase in intracellular $Ca^{2+}$ mobilization in C5a-stimulated neutrophils. Although protein kinase C inhibitors, staurosporine and H-7 inhibited intracellular $Ca^{2+}$ release in C5a-stimulated neutrophils, they did not affect $Ca^{2+}$ influx across the plasma membrane and elevation of $[Ca^{2+}]_i$ C5a-induced intracellular $Ca^{2+}$ release and $Ca^{2+}$ influx were inhibited by protein tyrosine kinase inhibitors, genistein and methyl-2,5-dihydroxycinnamate. ADP-evoked elevation of $[Ca^{2+}]_i$ was inhibited by genistein and methyl-2,5-dihydroxycinnamate but was not affectd by staurosporine and H-7. Genistein and methyl-2,5-dihydroxycinnamate reduced the store-regulated $Ca^{2+}$ influx in thapsigargin-treated neutrophils, while the effect of staurosporine and H-7 was not detected. When neutrophils were preincubated wih phorbol 12-myristate 13-acetate, the stimulatory effect of C5a on the elevation of $[Ca^{2+}]_i$ was reduced. These results suggest that protein tyrosine kinase may be involved in control of intracellular $Ca^{2+}$ release and $Ca^{2+}$ influx across the plasma membrane in C5a-activated neutrophils.

• Journal of the Korean Applied Science and Technology
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• v.14 no.2
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• pp.87-91
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• 1997

서로 다른 씨클로펜타디엔 유도체가 ${\pi}$-결합된 최초의 비스무스 화합물인 ${\eta}^5-C_5(CH_3)_5Bi({\eta}^5-C_5H_5)_2$이 디펜타메틸씨클로펜타디에닐 비스무스디메틸아미드 $Cp{\ast}_2BiNMe_2[Cp{\ast}=C_5(CH_3)_5]$와 씨클로펜타디에닐 모노머와의 반응으로 합성되었다. 반응조건은 에테르 용매하에 -78$^{\circ}C$ 반응온도 조건하에서 얻어졌다. 합성된 반응물을 노르말 헥산 용매에서 재결정시킨 결과, 검은색 결정이 60% 수율로 얻어졌다. 그리고 재결정시킨 반응물을 190K에서 X-선 단결정 구조 분석 방법에 의해 그 구조를 밝혔다. 그 결과 결정계의 격자계는 I2/a, a=1756.00 picometer, b=906.00 picometer, c=2211.00 picometer, ${\beta}$=104.04, Z=8로 확인되었다. 여기서 a, b, c는 결정�Ю� 상수이고, ${\beta}$는 결정격자 상수인 b와 c간의 각도이며, Z는 단위 결정 격자당 분자의 갯수이다.

• Korean journal of food and cookery science
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• v.9 no.4
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• pp.323-328
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• 1993

Benzo(a)pyrene [B(a)P], one of the polycyclic aromatic hydrocarbons (PAHs) is known as a potent carcinogen. As lipid consumption increases recently, the toxic effect of overheated lipid foods and fats ＆ oils were reported increasingly. In this study, the contents of B(a)p, other PAHs and rancidities of soybean oil were determined, and then the proper heating temperature, time and frequency were recommended, The work was carried out using soybean oil heated at $180\pm$5^{\circ}C$$, $200\pm$5^{\circ}C$$, and $300\pm$5^{\circ}C$$,for 50 hours. Acid Value(AV) and Conjugated Diene Value of samples were determined. The contents of B(a)P and other PAHs contents of all samples were masured by HPLC/UV method. The results obtained were as follows; Each content of PAHs in the fresh soybean oil was: Pyr 1.093, B(a)A 0.986, Ch 1.147, DMBA 1.082, B(e)P 0.664, Per 1.135, B(a)P 0.146, DBA 1.053, 3-MC 0.05 rg/kg. When the soybean oil was heated at $180\pm$5^{\circ}C$$, for 10, 20, 30, and 50 hours, B(a)P conterlts in heated soybean oils were 0.391, 0.692, 0.451, and 0.372 $\mu\textrm{g}$/kg respectively. Acid value of them were 0.26, 0.26, 0.29, and 0.33, and conjugated diene value was 0.67, 0.76, 0.99, and 1.04, respectively. When the soybean oil was heated at $200\pm$5^{\circ}C$$,and $300\pm$5^{\circ}C$$,for 10, 20, 30, and 50 hours, B(a)P coiltents in soybean oil heated at $200\pm$5^{\circ}C$$,were 0.844, 0.512, 0.479 and 0.247 Ig/kg respectively, Acid value 0.22, 0.21, 0.23 and 0.51 and CDNV 0.39, 0.49, 3.27, and 3.89. B(a)P contents in soybean oil heated at $300\pm$5^{\circ}C$$,were 0.466, 0.706, 0.607 and 0.247$\mu\textrm{g}$/kg respectively, Acid value 0.47, 1.57, 3.90, and 6.42 and CDNV 0.65, 2.15, 3.00, and 3.88.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.3
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• pp.147-154
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• 1992

Laminar natural convection heat transfer from a hot body in a square enclosure has been studied for various center positions of a hot square at Grashof number $Gr=1.5{\times}10^5$, Prandtl number Pr=0.71 and dimensionless thermal conductivity $k_g/k_f=14710$. The natural convection at the center position of a hot square; $X_c$, $Y_c=0.5$, 0.2 shows the most strong and at $X_c$, $Y_c=0.5$, 0.7 the most weak. The total mean Nusselt number at $X_c$, $Y_c=0.5$, 0.2 was 7.4% higher than that at $X_c$, $Y_c=0.2$, 0.5. The total mean Nusselt number at $X_c$, $Y_c=0.5$, 0.7 was 5.0% lower than that at $X_c$, $Y_c=0.3$, 0.5.