• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.163-170
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• 1988

The MNDO calculations were performed on the various rotamers of N-methyl formamide, N,N-dimethyl formamide, N-methyl acetamide, and N,N-dimethylacetamide in order to investigate the contribution of the one-electron and the steric effect on their rotational barriers about the C-N bond. Results show that while the conformational stabilities of formamides depend mainly on the one-electron factor, those of acetamides depend mainly on the steric factor. According to results obtained by calculations on the rotational barriers about C-N bond, for N-monosubstituted amides the steric effect is larger in the rotational ground state than in the transition state and for N,N-disubstituted amides the steric effect is larger in the rotational transition state.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.85-91
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• 1981

The growing cells of S. aureus were fractionated along the Schmidt-Thannhauser-Schneider's technique into several fractions such as TCA(trichloroacetic acid)-soluble, lipid, nucleic acid, protein and residue fraction. They were also fractionated according to their cellular structure into Sonic-supernatant, SDS(sodium lauryl sulfate)-soluble, Formamide-soluble and Residue fraction. Fractionation was carried out by orderly treatment of the Sonic pellet with 1.0% SDS and hot$(150^{\circ}C)$ formamide, and the pellet was prepared by centrifugation of the cells sonic osillated for 20 minutes at 150 watt. Sonic-supernatant fraction contained a 91.3% of total DNA while other fractions contained less than 9.5%. SDS-soluble fraction showed a high activity of malate dehydrogenase(13.67 unit/mg protein) and which was higher 22.3 times than the activity found from unsoluble fraction. Formamide-soluble fraction prepared from SDS-undoluble pellet by using the hot formamide exhibited a clear action of reducing sugars against the Anthronesulfate, while it exhibited no clear action against the ninhydrin. However, contrastly, the residue remainnning after extraction with formamide exhibited a clear action against ninhydrin and glucosamine was detected form the hydrolysate of residue by paper chromatography. From these results it is considered that the Sonic-supernatant fraction is mainly consisted of plasmic component of the cells. Other fractions, SDS-soluble, Formamide-soluble and Residue, should be consisted of plasma membrane, lipoplysaccharide and peptidoglycan of the cell, respectively.

• Journal of Industrial Technology
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• v.6
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• pp.49-55
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• 1986

A rapid and simple test to distinguish halloysite from kaolinite in mineral mixtures has been developed based on differences in the rate and extent of formamide intercalation. The results of quantitative analysis by formamide intercalation reaction GEC contained 90% of kaolin minerals, GEC contained of 86% of halloysite and GYK contained of 59% kaolinite. The extent of formamide intercalation by kaolinite was likely influenced by sample crystallinity.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.22-26
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• 1991

Potential energy surfaces for the proton transfer in a formamide dimer have been obtained by ab initio SCF calculations with STO-3G, 3-21G, and 4-31G basis sets and several features have been discussed. Energy minima for a formamide dimer and its tautomer are varied with basis sets. But the general features of the potential energy surfaces are similar among them.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.488-491
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• 1989

Theoretical studies on the proton transfer reaction in a formamide dimer have been done by Ab initio SCF calculation. In this study, we have shown several effects on the potential energy profile of the proton transfer in a formamide dimer, such as the effect of a basis set, the effect of a geometry optimization, and the effect of a distance between proton-donor and proton-acceptor.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.91-98
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• 2015

Formamide의 중성가수분해 mechanism은 QM/MM (quantum mecahnics/molecular mechanics) molecular dynamics simulations 및 CPMD과 같은 방법으로 연구되어왔다. 본 연구에서는. Umbrella sampling을 이용한 QM/MM-MD simulation을 사용하여 4가지 반응의 free energy surface를 도출해냈다. 전체적으로, 가장 선호되는 메커니즘은 two step으로 구성된 water assisted stepwise mechanism이었으며 모든 mechanism은 ab-initio calculation과 QM/MM-MD simulation이 수행되었다. water assisted stepwise mechanism을 살펴보면, 첫 번째 step에서 formamide의 carbonyl group이 hydrate되면서 gem-diol intermediate를 형성한다. 다음 step에서, intermediate의 hydroxyl group으로부터 amino group으로 water-assisted proton transfer이 일어난다. 두 반응 모두에서 물이 proton transfer를 직접적으로 도와주는 것을 관찰할 수 있었다. 특히, ab-initio calculation과는 다르게 QM/MM-MD에서는 gem-diol intermediate가 안정화되는 것으로 solvent effect를 잘 보여준다.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3634-3640
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• 2011

We have performed quantum mechanical calculations to study the geometries and binding energies of biologically important, cyclic hydrogen-bonded complexes, such as formic acid + $H_2O$, formamidine + $H_2O$, formamide + $H_2O$, formic acid dimer, formamidine dimer, formamide dimer, formic acid + formamide, formic acid + formamidine, formamide + formamidine, and barrier heights for the double proton transfer in these complexes. Various ab initio, density functional theory, multilevel methods have been used. Geometries and energies depend very much on the level of theory. In particular, the transition state symmetry of the proton transfer in formamidine dimer varies greatly depending on the level of theory, so very high level of theory must be used to get any reasonable results.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.637-638
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• 2006

Bioassay-guided fractionation of an organic extract of the culture broth from an unidentified marine-derived fungus led to the isolation of a new metabolite, N-[2-(4-hydroxyphenyl) acetyl]formamide (1), along with four known polyketides, 4-hydroxyphenyl acetamide (2), 4-hydroxyphenyl acetic acid (3), 3,4-dihydroxyphenyl acetic acid (4), and N-[2-(4-hydroxyphenyl)ethenyl]formamide (5). The structures of 1-5 were elucidated by spectral data analyses. Among them, compounds 1, 4, and 5 exhibited significant radical scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 8.4, 11.9, and $0.2{\mu}M$, respectively.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.520-529
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• 2017

Viscosity data were measured at 298.15 K and 308.15 K for formamide + 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol or 2-methyl-2-propanol mixtures. For an equimolar mixture, deviation in viscosity follows the sequence: 2-methyl-2-propanol >2-methyl-1-propanol>1-butanol>2-propanol>1-propanol. The viscosity data were further analyzed in terms of graph theory. Free energy of activation was also calculated from experimental viscosity data along with previously reported excess volume data. The deviation in viscosity and free energy of activation were fitted to Redlich-Kister polynomial equation. The viscosity data were also correlated by correlations like Grunberg-Nissan, Tamura-Kurata, HindMcLaughlin-Ubbelohde, and Katti-Chaudhari relation. Various adjustable parameters, $G_{12}$, $T_{12}$, $H_{12}$, and $W_{vis}/RT$, of various correlations were used to predict viscosity deviation of binary mixtures. Positive value of $G_{12}$ indicates strong interaction in the studied systems. Grunberg-Nissan relation has lowest deviation among the four correlations for formamide + 1-propanol or 2-propanol mixtures; and for mixtures of formamide with 1-butanol or 2-methyl-1-propanol, TamuraKurata has lowest deviation. Grunberg-Nissan gives lowest deviation for formamide + 2-methyl-2-propanol mixtures.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.111.1-111
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• 2002