• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1520-1524
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• 2005

This paper describes the racemic and stereoselective synthetic route for a novel 4'$\alpha$-phenyl and 6'$\alpha$-methyl doubly branched carbocyclic nucleosides from an acyclic 2-hydroxy acetophenone. The installation of phenyl group at the 4'-position of carbocyclic nucleoside was successfully accomplished via a sequential [3,3]-sigmatropic rearrangement. The stereoselective introduction of a methyl group in the 6'$\alpha$-position was accomplished by Felkin-Anh controlled alkylation. Bis-vinyl 11 compound was successfully cyclized using a Grubbs’ catalyst II to desired carbocycles. The natural bases (adenine and cytosine) were efficiently coupled using a Pd(0) catalyst. Although all the synthesized compounds were examined for their activity against several viruses such as HIV-1, HSV-1, HSV-2 and HCMV, only cytosine analogues 17 exhibited weak antiviral activity against HCMV.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.385-390
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• 1998

Adozelesin and carzelesin are synthetic analogues of the extremely potent antitumor antibiotic CC-1065, which alkylates N3 of adenine in a consensus sequence $5^1$-(A/T)(A/T)$A^*$ ($A^*$ is the site of alkylation). We have investigated the DNA sequence selectivity of adozelesin and carzelesin by thermally ind ced DNA strand cleavage assay using radiolabeled restriction DNA fragments. An analysis of alkylation patterns shows that the consensus sequences for carzelesin and adozelesin have been found to be $5^1$-(A/T)(A/T)$A^*$ and $5^1$-(A/F)(G/C)(A/T)$A^*$. A new consensus sequence, $5^1$-(A/T)(A/T)$CA^*$, has been observed to display an additional alkylation site for adozelesin but not for carzelesin. These results indicate that the pattern of sequence selectivity induced by carzelesin is similar but not identical to those induced by adozelosin.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.383-386
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• 2002

In this paper, we investigated the pattern recognition performance of the numeric patterns (from 0 to 9) using DNA coding method. The pattern recognition performance of the DNA coding method is compared to the that of the GA(Genetic Algorithm). GA searches effectively an optimal solution via the artificial evolution of individual group of binary string using binary coding, while DNA coding method uses four-type bases denoted by A(Adenine), C(Cytosine), G(Guanine) and T(Thymine), The pattern recognition performance of GA and DNA coding method is evaluated by using the same genetic operators(crossover and mutation) and the crossover probability and mutation probability are set the same value to the both methods. The DNA coding method has better characteristics over genetic algorithms (GA). The reasons for this outstanding performance is multiple possible solution presentation in one string and variable solution string length.

• Proceeding of EDISON Challenge
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• 2013.04a
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• pp.67-75
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• 2013

최근 이상기후의 원인으로 손꼽히는 물질의 중심에는 이산화탄소가 있으며 이를 제거하기 위한 여러 연구가 진행되고 있다. 최근에는 전극이 있는 수조에 미생물을 넣고 이산화탄소를 화학적 에너지로 사용할 수 있도록 알코올로 변환시켜주는 시스템이 발표되었다. 이에 따라 본 연구진에서는 이러한 전극 시스템에서 이용될 수 있는 효소를 찾고 효소촉매화 반응의 메커니즘을 자세히 연구하고자 하였다. 본 연구에서 사용된 효소인 Formate dehydrogenase (FDH)는 formate를 조효소인 nicotinamide adenine dinucleotide ($NAD^+$)를 사용하여 이산화탄소로 산화시키는 반응을 촉진시키는 효소이다. 본 연구에서는 이러한 FDH의 산화반응의 역반응을 이용하여 이산화탄소를 효과적으로 분해하는 메커니즘을 연구하기에 앞서 wild type의 반응 메커니즘에 대해 깊이 연구하고자 B3LYP 방법의 양자계산을 하여 반응의 transition state와 potential energy를 조사하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.6
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• pp.510-514
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• 2011

Based on first-principles LCAO method, we study the electronic and atomic structures of DNA nucleobases adenine (A), thymine (T), guanine (G), and cytosine (C) adsorbed on graphene surfaces. The ${\pi}-{\pi}$ stacking interactions between graphene and nucleobases lead to the bilayer geometries similar to the Bernal stacked graphite. Through the density of states and charge density analyses, it is found that nucleobases are physisorbed on graphene by dispersive interactions with negligible charge exchange. Our calculations reproduce the atomic structures obtained in previous plane wave calculations accurately with much less computation, and well describe the delocalized ${\pi}-{\pi}$ interactions in graphene-nucleobases system, indicating that the LCAO method is very efficient for investigating graphene-bio systems.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.46-50
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• 1986

Experiments with particulate fractions of Acinetobacter sp. 1 revealed that coeuzyme $Q_{10}$ is not the physiolohical electron acceptor, and that cytochromes of a, b, c, and o types are found in cells grown with carbon monoxide (CO) as the sole source of carbon and energy. It was found that cytochromes of b and o types, but not the a and c types, are functional in CO oxidation. Nicotinamide adenine dinucleotide (phosphate) is not involved in CO oxidation.

• Journal of the korean society of oceanography
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• v.31 no.2
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• pp.97-106
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• 1996

Advantages and disadvantages of four radioisotopic methods, $^{3}H$-thymidine, $^{3}H$-adenine, $^{3}H$-leucine, and $^{35}S$-sulfate, for measuring bacterial production were reviewed. The maior issues discussed in production methods were: (1) whether all the actively growing bacteria take up the radiolabeled (organic) tracers; (2) how each target molecule should be purified (nonspecific labeling); and (3) how important the determination of the precursor pool specific activity is (internal isotope dilution). Since all the radioisotoic methods have their own advantages and disadvantages, careful consideration must be paid in choosing the radioisotope according to the conditions of each environment investigated.

• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.114-118
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• 1994

In order to compare the contents of nucleic acid substances in various wines, the contents of nueleic acids were analyzed by HPLC. The contents of cytosine was found to decrease in the order of cherry wine > plum wine > dongdongju > chungha > pineapple wine > soju. The contents of guanine was found to decrease in the order of dongdonglu > chungha > pineapple wine > cherry wine > plum wine > soju. The contents of uridine was found to decrease in the order of dongdongju > chungha> cherry wine > pineapple wine > plum wine > soju. The contents of adenine was found to decrease in the order of dongdonglu > chungha > cherry wine > pineapple wine > plum wine > solu. The contents of guan oslne was found to decrease in the order of dongdongju > cherry wine > chungha > plum wine > pine-apple wine > soju. The contents of adenosine was found to decrease in the order of dongdongju > shun aha > cherry wine > plum me > pineapple wine > soju.

• Bulletin of the Korean Chemical Society
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• v.18 no.5
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• pp.510-514
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• 1997

We studied the interaction of 4',6-diamidino-2-phenylindole (DAPI) with single stranded poly(dA) using optical spectroscopic methods, including absorption, circular dichroism (CD), and fluorescence spectroscopy. The temperature-dependent conformation of poly(dA) was also investigated. The conformation of poly(dA) varied with temperature, which is explained by the stacking-destacking process of the adenine bases, resulting from the sugar conformation. The hypochromicity and red-shift in the absorption spectroscopy, the lack of CD change in the drag absorption region, and the fluorescence behavior, especially a great accessibility of the I2 quencher to the poly(dA)-bound DAPI, suggest that DAPI binds to the outside of poly(dA). The Job plot for the DAPI-poly(dA) mixture demonstrated that a stoichiometry of one DAPI molecule binds to the one phosphate of poly(dA).

• Bulletin of the Korean Chemical Society
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• v.18 no.11
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• pp.1149-1152
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• 1997

An enzyme electrode for the amperometric measurement of urea was prepared by co-immobilizing L-glutamate dehydrogenase and urease onto an Immobilon-AV affinity membrane attached to a glassy carbon electrode. The reduced nicotinamide adenine dinucleotide(NADH) was used as the electroactive species. The electrochemical oxidation of NADH was monitored at +1.0 volt vs. Ag/AgCl. The enzyme-immobilized electrode was linear over the range of 2.0 × 10-5 to 2 × 10-4 M. The response time of the electrode was approximately 3 min. and the optimum pH of the enzyme immobilized membrane was pH 7.4-7.6 (Dulbcco's buffer solution). It was stable for at least two weeks or 50 assays. There was no interference from other physiological species, except from high levels of ascorbic acid.