• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3382-3388
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• 2011

Reaction of barbituric acid (BA), 1,3-dimethyl barbituric acid (DMBA) and 2-thiobarbituric acid (TBA) with cyanogen bromide and aldehydes in the presence of L-(+)-tartaric acid afforded a new route for the synthesis of stable heterocyclic 5-aryl-1H,1'H-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine]2,2',4,4',6'(3H,3'H,5H)-pentaones which is a dimeric form of barbiturate (uracil and thiouracil derivative). In the reaction of 1,3-diethyl thiobarbituric acid (DETBA) the Knoevenagel condensation and then Michael adducts were obtained under the same condition. Structure elucidation is carried out by $^1H$ NMR, $^{13}C$ NMR, FT-IR and Mass analyses. Mechanism of the formation is discussed.

• Journal of the Korean Chemical Society
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• v.66 no.6
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• pp.442-450
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• 2022

Diverse pyrrolo[3,2-d]pyrimidines that are expected to exhibit bioactivity were synthesized through O-arylation and Suzuki coupling reactions. Microwave-assisted O-arylation was successfully performed using a Cu metal catalyst, so that 4 position of pyrrolo[3,2-d]pyrimidine could be substituted with phenol group. In addition, 4-aryl substituted pyrrolo[3,2-d]pyrimidines were synthesized with good to excellent yields by microwave-assisted Suzuki coupling reaction using a Pd metal catalyst. By using microwaves as reaction conditions for diversification of derivatives, it was possible to dramatically overcome the disadvantages of traditional heat reactions of long reaction times and heat transfer efficiency problems. The result of this study can be used to be diversify pyrrolo[3,2-d]pyrimidine derivatives, which are expected to play an important role in the drug discovery research.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.97-100
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• 1990

A convenient route is reported for the synthesis of fused pyrrolo [2, 3-d][1, 3]-oxazine and pyrrolo [2, 3-d]-pyrimidine derivatives from 2-amino-1-benzyl-3-t-butoxy-carbonyl-4, 5-dimethylpyrrole.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.9-19
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• 2011

The Bacillus subtilis pyrimidine biosynthetic (pyr) operon encodes all of the enzymes for the de novo biosynthesis of Uridine monophosphate (UMP) and additional cistrones encoding a uracil permease and the regulatory protein PyrR. The PyrR is a bifunctional protein with pyr mRNA-binding regulatory funtion and uracil phosphoribosyltransferase activity. To study the global regulation by the pyrR deletion, the proteome comparison between Bacillus subtilis DB104 and Bacillus subtilis DB104 ${\Delta}$pyrR in the minimal medium without pyrimidines was employed. Proteome analysis of the cytosolic proteins from both strains by 2D-gel electrophoresis showed the variations in levels of protein expression. On the silver stained 2D-gel with an isoelectric point (pI) between 4 and 10, about 1,300 spots were detected and 172 spots showed quantitative variations in which 42 high quantitatively variant proteins were identified. The results showed that production of the pyrimidine biosynthetic enzymes (PyrAA, PyrAB, PyrB, PyrC, PyrD, and PyrF) were significantly increased in B. subtilis DB104 ${\Delta}$pyrR. Besides, proteins associated carbohydrate metabolism, elongation protein synthesis, metabolism of cofactors and vitamins, motility, tRNA synthetase, catalase, ATP-binding protein, and cell division protein FtsZ were overproduced in the PyrR-deficient mutant. Based on analytic results, the PyrR might be involved a number of other metabolisms or various phenomena in the bacterial cell besides the pyrimidine biosynthesis.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1790-1800
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• 2002

The DNA nucleosides(dA, dC, dG, dT)bound to gold nanoparticles (~13 nm) in aqueous solution has been studied as a probe by the SERS and their coordination structures have been proposed on the basis of them. According to UV-Visible absorption of gold nanoparticles after modifying with DNA nucleosides, the rates of absorption of dA, dC, and dG were much faster than that of dT as monitored by the aggregation kinetics at 700 nm. These data indicated that the nucleosides dA, dC, and dG had a higher affinity for the gold nanoparticles surface than nucleoside dT. As the result of SERS spectra, the binding modes of each of the nucleosides on gold nanoparticles have been assigned. A dA binds to gold nanoparticles via a N(7) nitrogen atom of the imidazole ring, which the C(6)-$NH_2$ group also participates in the coordination process. In the case of dC, it binds to the gold surface via a N(3) nitrogen atom of the pyrimidine ring with a partial contribution from the oxygen of C(2)=O group. A coordination of dG to the gold surfaces is also proposed. Although the dG has the two different nitrogens of a pyrimidine ring and the amino group, the N(1) nitrogen atom of a pyrimidine ring has a higher affinity after the hydrogen migrates to the amino group. Conversely, dT binds via the oxygen of the C(4)=O group of the pyrimidine ring. Accordingly, these data suggest that the nitrogen atom of the imidazole or the pyrimidine ring in the DNA nucleosides will bind more fast to the gold nanoparticles surfaces than the oxygen atom of the carbonyl group.

• Bulletin of the Korean Chemical Society
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• v.29 no.11
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• pp.2231-2236
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• 2008

• Proceedings of the Microbiological Society of Korea Conference
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• 2006.05a
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• pp.105-107
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• 2006

Two kinds of nucleoside hydrolases (NHs) encoded by rih1 and rih2 were cloned from Corynebacterium ammoniagenes using deoD- and gsk-defective Escherichia coli. Sequence analysis revealed that NH 1 was a protein of 337 aa with a deduced molecular mass of 35,892 Da, whereas NH 2 consisted of 308 aa with a calculated molecular mass of 32,310 Da. Experiments with crude extracts of IPTG-induced E. coli CGSC 6885(pTNU23) and 6885(pTNI12) indicated that the Rihl enzyme could catalyse the hydrolysis of uridine and cytidine and showed pyrimidine-specific ribonucleoside hydrolase activity. Rih2 was able to hydrolyse both purine and pyrimidine ribonucleosides with the following order of activity-inosine>adenosine>uridine>guanosine>xanthosine>cytidine-and was classified in the non-specific NHs family. rih1 and rih2 deletion mutants displayed a decrease in cell growth on minimal medium supplemented with pyrimidine and purine/pyrimidine nucleosides, respectively, compared with the wild-type strain. Growth of each mutant was substantially complemented by introducing rih1 and rih2, respectively. Furthermore, disruption of both rih1 and rih2 led to the inability of the mutant to utilize purine and pyrimidine nucleosides as sole carbon source on minimal medium. These results indicated that rih1 and rih2 play major roles in the salvage pathways of nucleosides in this micro-organism.

• Journal of the Korean Chemical Society
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• v.19 no.2
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• pp.130-133
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• 1975

The 4'-thio analogs of the 5-bromo-and 5-iodo-pyrimidine nucleosides were prepared by condensation of 2,3,5-tri-O-acetyl-4-thio-${\alpha},{\beta}$-D-ribofuranosyl chloride with the chloromercury derivatives of 5-halogeno-2,4-bis(trimethylsiloxy)pyrimidine, followed by the removal of the protecting groups. Although the biological activities of the 4'-thio derivatives are not greatly different from the corresponding 4'-oxygen analogs in this preliminary test, the fact that the 4'-thio analogs have comparableihigh activities, is of interest, and indicates the value of further biochemical examinations.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.986-988
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• 2005

• Bulletin of the Korean Chemical Society
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• v.21 no.3
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• pp.321-327
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• 2000

Polynucleotide analogues containing pyrimidine (uracil and thynime) bases, $poly[(1'{\beta}-uracil-1-yl-2'.5'-dideoxy-D-glycero-pent-4'-enofuranose)-alt-(maleic$ acid)] (12) and $poly[(1'-{\beta}-thymin-1-yl-2'5'-dideoxy-D-glycero-pent-4'-enofuranose)-alt-(maleic$, acid)] (15), were synthesized by the altermating copolymerization of relevant nucleosied derivatives and maleic anhydride, and the subsequent hydrolysis. The polymers had quite similar structures to the natural polymes and were soluble in water, They showed high hypochromicities up to 49% and excimer fluorescence due to the base stacking, and polyelectrolyte behavior. Since the polymers had compact structrures, depyrimidinations, the release of pyrimidine bases from the polymer backbone, occurred in aqueous solutions with higher rates compared with those of the natural polymers.