• Molecules and Cells
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• v.42 no.11
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• pp.773-782
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• 2019

Cellular senescence is an irreversible form of cell cycle arrest. Senescent cells have a unique gene expression profile that is frequently accompanied by senescence-associated heterochromatic foci (SAHFs). Protein kinase CK2 (CK2) downregulation can induce trimethylation of histone H3 Lys 9 (H3K9me3) and SAHFs formation by activating SUV39h1. Here, we present evidence that the PI3K-AKT-mTOR-reactive oxygen species-p53 pathway is necessary for CK2 downregulation-mediated H3K9me3 and SAHFs formation. CK2 downregulation promotes SUV39h1 stability by inhibiting its proteasomal degradation in a p53-dependent manner. Moreover, the dephosphorylation status of Ser 392 on p53, a possible CK2 target site, enhances the nuclear import and subsequent stabilization of SUV39h1 by inhibiting the interactions between p53, MDM2, and SUV39h1. Furthermore, $p21^{Cip1/WAF1}$ is required for CK2 downregulation-mediated H3K9me3, and dephosphorylation of Ser 392 on p53 is important for efficient transcription of $p21^{Cip1/WAF}$. Taken together, these results suggest that CK2 downregulation induces dephosphorylation of Ser 392 on p53, which subsequently increases the stability of SUV39h1 and the expression of $p21^{Cip1/WAF1}$, leading to H3K9me3 and SAHFs formation.

• Journal of the Korean Chemical Society
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• v.38 no.4
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• pp.302-308
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• 1994

Homogeneous catalytic oxidation of hydrazobenzene was investigated by employing pentadentate Schiff base complexes such as [Co(II)(Sal-DPT)(H$_2$O)] and [Co(II)(Sal-DET)(H$_2$O)] in oxygen-saturated methanol solvent. The oxidation product of hydrazobenzene(H$_2$AB) was trans-azobenzene(trans-AB). The rate constants of oxidation reaction measured by UV-visible spectrophotometry were observed as $6.06{\times}10^{-3}sec^{-1}$ for [Co(II)(Sal-DPT)(H$_2$O)] and $2.50{\times}10^{-3}sec^{-1}$ for [Co(II)(Sal-DET)(H$_2$O)]. The mechanism of oxidation reaction for H$_2$AB by homogeneous activated catalysts has been proposed as following. H$_2$AB + Co(II)(L)(H$_2$O) + O$_2$ $\rightleftharpoons^K_{MeOH}Co(III)(L)O_2{\cdot}H_2AB + H_2O\longrightarrow^{k}Co(II)(L) + trans-AB + H_2O_2$ (L: Sal-DPT and Sal-DET)

• Journal of Ginseng Research
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• v.19 no.1
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• pp.45-50
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• 1995

(20S)- and (20R)-protopanaxadiol were prepared from crude ginseng saponin by chemical treatment. The $^{1}H$- and $^{13}C$-NMR signals of these compounds were fully assigned by various NMR techniques such as DEPT, 1H-1H COSY, HMQC, HMBC and NOESY.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.59-63
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• 1997

A method for the calculation of the idealized hydrogen positions in the following seven different kinds of compounds has been shown: (1) tertiary C-H, (2) secondary C-H, (3) $CH_3$ group with tetrahedral angles, (4) aromatic C-H or amide N-H, (5) O-H group with X-O-H angle tetrahedral, (6) terminal $X=CH_2$ or $X=NH_2^+$ with the hydrogen atoms in a plane and (7) acetylenic C-H with X-C-H linear.

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.338-341
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• 1986

Hydrocarbon solution of $Ir(PPh_3)_2(CO)OClO_3$ reacts with $Ph_2PC_6H_4$-o-CHO and 3-methyl-2-aminopyridinyl aldimine to yield ${\bar{Ir(Ph_2PC_6H_4-o-CO)}}\;(PPh_3)_2(CO)(H)ClO_4$(1) and ${\bar{Ir(NC_6H_6NC}}C_6H_5)(PPh_3)_2(CO)(H)ClO_4$(2), respectively. The compound $Ir(PPh_3)_2N_2Cl$ also reacts with $Ph_2PC_6H_4$-o-CHO and 3-methyl-2-aminopyridinyl aldimine to give ${\bar{Ir(Ph_2PC_6H_4-o-C}}O)(PPh_3)_2(H)Cl(3)$ and $Ir(NC_6H_5NCC_6H_5(PPh_3)_2(H)Cl(4)$, respectively. Compounds 1, 2, 3, and 4 were characterized by infrared, $^1H$ NMR, $^{31}p$ NMR, UV spectra, and conductivity measurements.

• Journal of the Korean Magnetics Society
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• v.26 no.3
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• pp.71-75
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• 2016

Monolayer $MoS_2$ is energetically most stable when it has a 1H phase, but 1H to 1T phase transition ($1H{\rightarrow}1T$) is easily realized by various ways. Even though magnetic moment is not observed during $1H{\rightarrow}1T$, $0.049{\mu}_B/MoS_2$ is obtained in local 1T phase; 75% 2H and 25% 1T phases are mixed in ($2{\times}2$) supercell. Most magnetic moment is originated from the 1T phase Mo atom in the supercell, while the magnetic moments of other atoms are negligible. As a result, magnetic/non-magnetic boundary is created in the monolayered $MoS_2$. Our result suggests that $MoS_2$ can be applied for spintronics such as a spin transistor.

• Journal of the Korean Chemical Society
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• v.18 no.3
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• pp.194-201
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• 1974

The tetradentate schiff base ligand, N,N'-bis(salicylaldehyde)-m-phenylenediimine has been prepared from salicylaldehyde and m-phenylenediamine by Duff-reaction. The schiff base ligand has been reacted with Cu(II), Ni(II), Co(II), and Zn(II) to form new complexes; Cu(II)$[C_{20}H_{14}O_2N_2]{\cdot}2H_2O, Ni(II)[C_{20}H_{14}O_2N_2]{\cdot}2H_2O, Co(III)[C_{20}H_{14}O_2N_2]{\cdot}2H_2O and Zn(II)2[C_{20}H_{14}O_2N_2]{\cdot}4H_2O$. It seems to be that the Cu(II), Ni(II) and Co(II) complexes have hexacoordinated configuration with the schiff base and two molecules of water, while Zn(II) complex has tetracoordinated configuration with the schiff base and four molecules of water. The mole ratio of tetradentate schiff base ligand to Cu(II), Ni(II) and Co(II) are 1:1 but to Zn(II) is 1:2. These complexes have been identified by visible spectra, infrared spectra, T.G.A. and elemental analysis.

• Journal of Pharmaceutical Investigation
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• v.16 no.2
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• pp.43-54
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• 1986

To increase the bioavailability of clonixin, clonixin argininate was prepared and compared with clonixin by determining solubility, pKa, lipid-water partition coefficient, dissolution rate and in vivo tests. The results are summerized as followings; 1) The solubility of clonixin argininate was increased by 20 times in water, about 1.2 times in pH 1.2 and pH 8.0 buffer solution, and about 1.8 times in pH 6.8 buffer solution compared with that of clonixin. 2) pKa values of clonixin, clonixin lysinate and clonixin argininate were 6.32, 7.20 and 7.45, respectively. 3) The lipid-water partition coefficient of clonixin argininate was increased more than that of the clonixin in n-hexane, carbon tetrachloride, chloroform, methylene chloride, and n-butanol, but the partition coefficient of clonixin was increased more than that of clonixin argininate in benzene/pH 1.2 buffer solution, ether/pH 8.0 buffer solution, and 3-methylbutyl acetate/pH 1.2, pH 8.0 buffer solution. 4) The time required to dissolve 60% $(T_{60%},\;min.)$ of clonixin argininate was about 1.5 min. in water and pH 1.2 buffer solution, and about 5 min. in pH 6.8 buffer solution. $T_{60%}$ of clonixin lysinate was about 1.5 min. in water, about 1.8 min. in pH 6.8 buffer solution, and about 8 min. in pH 1.2 buffer solution. But $T_{60%}$ of clonixin was about 96 min. in pH 6.8 buffer solution, over 2 hours in water and pH 1.2 buffer solution. 5) Anti-inflammatory effect of clonixin argininate was increased more than that of clonixin over 6 hours, and that of clonixin lysinate was followed by lapse of time. 6) Analgesic effect of clonixin argininate was increased by 1.5 times more than that of clonixin and the effect of clonixin argininate was nearly identical with that of clonixin lysinate. 7) The absorption rates (Ka) of clonixin, clonixin lysinate and clonixin argininate were $0.169\;hr^{-1},\;0.652\;hr^{-1}$ and $0.723\;hr^{-1}$ in situ, respectively.

• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.312-317
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• 1971

The interactions of aniline, o-toluidine, o-ethylaniline and o-chloroaniline with iodine in carbon tetrachloride solution have been examined through spectrophotometric measurements. The results indicate that both aniline and the o-substituted anilines examined form one-to-one complexes with I2in solution. The formation constants of the complexes measured at room temperature are 12.8, 9.31, 3.15 and 0.576 l $mole^{-1}$, respectively. Comparison of these results with previous experimental results indicates that the relative stabilities of the $I_2$-amine complexes decrease in the following order: $C_6H_5N(C_2H_5)_2 >C_6H_5N(CH_3)_2 >C_6H_5NH_2 >o-CH_3C_6H_4NH_2 >o-C_2H_5C_6H_4NH_2 >o-ClC_6H_4NH_2$. This may support the conclusion that the relative stabilities of these complexes are explained by the inductive effect and steric hindrance of the substituents.

• Environmental Mutagens and Carcinogens
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• v.23 no.1
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• pp.16-22
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• 2003

Single nucleotide polymorphisms (SNPs) are alterations in DNA base that occur most frequently throughout the human genome. The SNPs of DNA repair genes, hMLH1, hMSH2 and ATM, among 100 Korean people were analyzed using Dynamic Allele specific Hybridization (DASH) techniques. Mutation at the position of exon 38 (GA) and exon 10 (CG) of ATM gene, mutation at the position of exon 8 (AG), and exon 1 (AG) of hMLH1 gene and exon 14 (AG) of hMSH2 gene were investigated. No mutation at the selected position of ATM gene and hMSH1 gene was found. However, while there was no mutation at the position of exon of hMSH2 gene, mutation was found at the promotion region (CT) with the frequency of 24% CC, 36% CT and 62% TT genotyes. This results might be used as baseline data for research on SNP of Korean population.