• Journal of Microbiology
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• v.44 no.5
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• pp.530-536
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• 2006

Bacteriophage P4, a satellite phage of coliphage P2, is a very useful experimental tool for the study of viral capsid assembly and cos-cleavage. For an in vitro cos-cleavage reaction study of the P2-P4 system, new shortened and selectable markers containing P4 derivative plasm ids were designed as a substrate molecules. They were constructed by swapping the non-essential segment of P4 DNA for either the kanamycin resistance (kmr) gene or the ampicillin resistance (apr) gene. The size of the genomes of the resulting markers were 82% (P4 ash8 delRI:: kmr) and 79% (P4 ash8 delRI:: apr) of the wild type P4 genome. To determine the lower limit of genome size that could be packaged into the small P4-size bead, these shortened P4 plasmids were converted to phage particles with infection of the helper phage P2. The conversion of plasmid P4 derivatives to bacteriophage particles was verified by the heat stability test and the burst size determination experiment. CsCl buoyant equilibrium density gradient experiments confirmed not only the genome size of the viable phage form of shortened P4 derivatives, but also their packaging into the small P4-size head. P4 ash8 delRI:: apr turned out to be the smallest P4 genome that can be packaged into P4-sized head.

• Korean journal of food and cookery science
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• v.1 no.1
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• pp.33-39
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• 1985

The volatile sulfur components from two varieties of radishes ('Taeback' and 'Altali'), obtained by steam distillation and solvent ($CCl_4$) extraction, were isolated and charac-terized by GC/MS analysis. The GC profile of the volatile sulfur com-pounds in the steam distillates from two types of radishes was quite similar. 4-Me-thylpentyl, 3-methylthiopropyl, 4-methylthio-3-butenyl, 4-methylthiobutyl and 5-methyl-thiopentyl isothiocyanates, 5-methylthio-4-pentenenitrile, 1-methylthio-3-pentanone, and dimethyl sulfides were commonly identified. In the $CCl_4$ extract, 4-methylsulfinyl-3-bu-tenyl isothiocyanate was obtained as another major constituent. Whereas 4-methylthiobutyl isothiocyanate was found to be a predominent component in the steam distillate, 4-methylthio-3-butenyl isothiocyananate was a major one in the $C1_4$ extract.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.379-384
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• 2004

4-pyrimidylideneacetonitrile derivatives containing $BF_2$-chelate have been synthesized from H-chelates of 4-pyrimidylideneacetonitrile derivatives and boron trifluoride diethyl etherate. These H-chelates were prepared by the electrophilic substitution of 2-cyanomethylpyridine derivatives with electrophiles such as 4,6-dichloropyrimidine, 4,6-dichloro-2-methylpyrimidine, 4,6-dichloro-2-heptadecylpyrimidine, 4,6-dichloro-2-phenylpyrimidine, 4,6-dichloro-5-phenylpyrimidine and 4,6-dichloro-2,5-diphenylpyrimidine. Structures of the target molecules were identified by spectra methods.

• YAKHAK HOEJI
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• v.37 no.3
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• pp.295-305
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• 1993

In order to develop oral cephalosporin having a new substituent at 3 position, the synthesis of cephalosporins modified at C-3 and the effect of the substituents on the oral absorption is studied. 7-[(Z)-2-(2-Aminothiazole- 4-yl)-2-methoxyiminoacetamidol-3-[4-(2-pyridyl )piperazinyl] thiocarbonylthiomethyl-3-cephem-4-carboxylic acid (CEN1) and 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyrimid yl)piperazinylthiocarbonylthiomethyl-3-cephem-4-carboxylic acid (CEN2) were synthesized from 4-(2-piridyl)piperazinyl dithiocarbamate potassium salt or 4-(2-pirimidyl)piperazinyl dithiocarbamate potassium salt and cefotaxime. Also pivaloyloxymethyl esters of CEN1 and CEN2, pivaloyloxymethyl 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl )piperazinyllthiocarbonylthiomethyl-3-cephem-4-carboxylate (CENIP) and pivaloyloxymethyl 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamidol-3- [4-(2-pyrimid yl)piperazinyllthiocarbonylthiomethyl-3-cephem-4-carboxylate (CEN2P) were synthesized. The in vitro activities of two new oral cephalosporins, CEN1 and CEN2, were compared with the in vitro activities of cefaclor and cefotaxime against a variety of bacterial species. CEN2 has a broad antibacterial spectrum covering Gram-positive and Gram-negative bacteria, similar to that exhibited by CEN1 and cefotaxime. CEN1 and CEN2 were more active in vitro than cefaclor against Streptococcus pyogenes, Klebsiella aerogenes and Enterobacter cloacae.

• Journal of the Korean Chemical Society
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• v.30 no.6
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• pp.495-499
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• 1986

Structures of 4H-pyran-4-one(I), 4H-pyran-4-thione(II), 4H-thiapyran-4-one (III), 4H-thiapyran-4-thione(IV) have been determined by MNDO and MINDO/3 methods. Geometries and physicochemical properties, especially the aromaticity, were found to agree well with the results of microwave experiments. The order of aromaticity was found to be (IV) > (III) > (II) > (I), which demonstrated inhibitory effect of strongly electronegative oxygen atom on the electron delocaligation, and the order of dipole moment, (II) > (IV) > (I) > (III), indicated the dominant contribution of the bond length of carbonyl group (C=O or C=S)

• YAKHAK HOEJI
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• v.19 no.2
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• pp.96-100
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• 1975

2-Ethoxy-4-acetamidobenzoate (III) was synthesized by ethylation of N-formyl compound obtained with formylation of methyl 4-aminosalicylate and 2-ethoxy-4-acetamidobenzamide (VIII) was synthesized by ethylation of 4-acetamidosalicylamide (VII) formed by reacting methyl 4-acetamido-2-acetoxy benzoate with concentrated ammonia water under pressure. 2-Ethoxy-4-acetamido benzamide (VIII) was also synthesized by acetylation of 2-ethoxy-4-aminobenzamide (VI) obtained by pressure eraction of methyl 2-ethoxy-4-formylamido-benzoate (I) with concentrated ammonia water.

• Journal of the Mineralogical Society of Korea
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• v.23 no.2
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• pp.117-124
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• 2010

The sorption of $AsO_4,\;SeO_3,\;CrO_4$ on schwertmannite and thermal analysis of sorbed samples were carried out. The results of sorption experiments showed that sorption characteristics of those three oxyanions on schwertmannite can be divided into two groups. The extent of sorption of $AsO_4$ and $SeO_3$ were 100% at up to 1 mM solution concentration, and they increased no more significantly. This can be interpreted as $AsO_4$ and $SeO_3$ substituting $SO_4$ in schwertmannite strucure by the ratio of 1 : 1. The extent of the sorption of $CrO_4$ was much lower than those of other two oxyanions. Thermal analysis was performed using two kinds of sorbed samples at 0.1 and 1.25 mM concentrations. The results of the thermal analysis showed that the samples sorbed by three different oxyanions have different thermal characteristics. The samples sorbed by $AsO_4$ showed smaller weight loss around $600^{\circ}C$ than the original loss of pure schwertmannite, and it is attributed to the substitution of $AsO_4$ for $SO_4$, which was caused by the loss of $SO_4$, than pure schwertmannite due to the substitution of $SO_4$ by $AsO_4$. It also showed additional weight loss around $600^{\circ}C$ due to the decomposition of $AsO_4$ at that temperature. The weight loss of samples sorbed by $SeO_3$ started at slightly lower temperature than that sorbed by $SO_4$ and kept that loss at wider temperature range, probably indicating that the decomposition of $SeO_3$ occurs at slightly lower temperature. However, for the samples sorbed by $CrO_4$, the weight loss caused by the decomposition of $SO_4$ was also smaller and there was no additional weight loss at higher temperature due to the thermal stability of $CrO_4$, indicating that $SO_4$ was also substituted by $CrO_4$ in schwertmannite. Sorption experiment and thermal analysis indicate that $CrO_4$ sorbs on schwertmannite by substiuting $SO_4$, but the affinity to $SO_4$ or instability of $CrO_4$ in scwertmannite structure probably prohibit perfect 1 : 1 substitution.

• Korean Journal of Crystallography
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• v.18 no.1_2
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• pp.16-20
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• 2007

Under hydrothermal conditions, a 2-dimensional copper(I) coordination polymer [$Cu_2Cl_2$(4,4'-dipyen)] (1) was prepared from [$Cu(OAc)_2]{\cdot}H_2O$, 4,4'-dipyen, and KCl. In polymer 1, copper atoms are linked by the 4,4'-dipyen ligands approximately along the b-axis and are also linked by the chloro ligands approximately along the a-axis to form a 2-D layer, a network of rectangles.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.6
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• pp.52-54
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• 1982

p·Si-전해질 접합을 전해질로 6N H2SO4, 6N H2SO4(Ti3+), 6N H2SO4(Ti4+), 6N H2SO4(Ti4+/Ti3+)을 사용하여 만들었다. 이들 전해질중 6N H2SO4(Ti4-/Ti3+)을 사용할 때 p·Si 광음극이 안정하게 동학하며 높은 광전 감도를 가지고 있었다. p·Si-electrolyte junction are prepared by using p·Si photocatode in four different electrolytes such as 6N H2SO4, 6N H2SO4(Ti3+), 6N H2SO4(Ti4+), 6N H2SO4(Ti4+/Ti3+) respectively. Among those electrolytes 6N H2SO4(Ti4-/Ti3+) shows very good results, in which p·Si photocathode is stable.

• Textile Coloration and Finishing
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• v.8 no.2
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• pp.49-55
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• 1996

Poly(4, 4'-diphenyl ether pyromellitamic acid) was prepared from pyromellitic anhydride with 4, 4'-diamino diphenyl ether by means of low-temperature solution polymeriztion. The reation was exothermic and very fast when carried out at room temperature. The synthesized poly(4, 4'-diphenyl ether pyromellitamic acid) was converted to poly(4, 4'-diphenyl ether pyromellitimide) by thermal dehydrocyclization. FTIR analysis was widely used as a means of determining the course of imidization from intensity of characteristic bands of the imide ring at $1790cm^{-1}$ and $1490cm^{-1}$. The density of poly(4, 4'-diphenyl ether pyromellitimide) was higher than poly(4, 4'-diphenyl ether pyromellitamic acid) indicating the greater crystallinity, perhaps because of the reduction of molar volume of polymers