• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.333-338
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• 2011

Black ginseng (BG) has been widely used as herbal treatment for improving physiological function. In order to investigate the neuroprotective action of this herbal medicine, we examined the influence of BG on the learning and memory of rats using the Morris water maze, and we studied the effects of BG on the central cholinergic system and neural nitric oxide synthesis in the hippocampus of rats with neuronal and cognitive impairment. After middle cerebral artery occlusion was applied for 2h, the rats were administered BG (100 or 400 $mgkg^{-1}$, p.o.) daily for 2 weeks, followed by training and performance of the Morris water maze test. The rats with ischemic insults showed impaired learning and memory on the tasks. Treatment with BG produced improvement in the escape latency to find the platform. Further, the BG groups showed a reduced loss of cholinergic immunoreactivity and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons in the hippocampus compared to that of the ISC group. These results demonstrated that BG has a protective effect against ischemia-induced neuronal and cognitive impairment. Our results suggest that BG might be useful for the treatment of vascular dementia.

• BMB Reports
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• v.42 no.6
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• pp.373-379
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• 2009

5-Hydroxyuridine (5-OHU) is a major lesion of uridine and cytosine produced in RNA by various chemical oxidants. To elucidate its biochemical and biophysical effects on RNA replication, the site-specifically modified oligoribonucleotides containing 5-OHU were synthesized with C5-hydroxy-5'-ODMTr-2'-TBDMS-uridine phosphoramidite using automated solid phase synthesis. The base-pairing properties of nucleotides opposite 5-OHU in 24 mer oligoribonulcleotides with dNTP were studied using three reverse transcriptases (Super-$Script^{TM}II$-, AMV-, MMLV-RT) in cDNA synthesis. Adenine as well as guanine was incorporated preferentially by all reverse transcriptases. In the UV-melting temperature experiment, the results from the relative stabilities of the base pairs were A : 5-OHU > G : 5-OHU > T : 5-OHU $\approx$ C : 5-OHU. Circular Dichroism (CD) studies showed that DNA-RNA containing 5- OHU heteroduplexes exhibit a similar conformation between the A-type RNA and B-type DNA. These results suggest that 5- OHU from oxidative damage was mainly influenced by adenine mismatch.

• Archives of Pharmacal Research
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• v.24 no.5
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• pp.455-465
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• 2001

The highly potent cytotoxic DNA-DNA cross-linker consists of two cyclopropa[c]pyrrolo[3,4-3]indol-4(5H)-ones insoles [(+)-CPI-I] joined by a bisamido pyrrole (abbreviated to "Pyrrole"). The Pyrrole is a synthetic analog of Bizelesin, which is currently in phase II clinical trials due to its excellent in vivo antitumor activity. The Pyrrole has 10 times more potent cytotoxicity than Bizelesin and mostly form DNA-DNA interstrand cross-links through the N3 of adenines spaced 7 bp apart. The Pyrrole requires a centrally positioned GC base pair for high cross-linking reactivity (i.e., $5^1$-T$AT_2$A*-$3^1$), while Bizelesin prefers purely AT-rich sequences (i.e., $5^1$-T$AT_4$A*-$3^1$, where /(equation omitted) represents the cross-strand adenine alkylation and A* represents an adenine alkylation) (Park et al., 1996). In this study, the high-field $^1$H-NMR and rMD studies are conducted on the 1 1-mer DNA duplex adduct of the Pyrrole where the 5′(equation omitted)TAGTTA*-3′sequence is cross-linked by the drug. A severe structural perturbation is observed in the intervening sequences of cross-linking site, while a normal B-DNA structure is maintained in the region next to the drug-modified adenines. Based upon these observations, we propose that the interplay between the bisamido pyrrole unit of the drug and central C/C base pair (hydrogen-bonding interactions) is involved in the process of cross-linking reaction, and sequence specificity is the outcome of those interactions. This study suggests a mechanism for the sequence specific cross-linking reaction of the Pyrrole, and provides a further insight to develop new DNA sequence selective and distortive cross-linking agents.

• Journal of Chest Surgery
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• v.26 no.6
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• pp.441-451
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• 1993

Protective effect of superoxide dismutase[SOD] and substrates on acute ischemic and reperfused myocardium was assessed by cardiac microdialysis. 30 Rabbits were divided into 4 groups; normal control group [group I, n=5], ischemic group [group II, n=5], SOD treated group [group III, n=10], and substrates treated group [group IV, n=10]. After a microdialysis apparatus was implanted in rabbit myocardium, coronary artery was occuluded for 5 minutes and reperfusion was performed for 30 minutes. Hemodynamic changes, CK-MB isoenzyme level and adenine ring compound level in effluent dialysates [equilibrated with interstitial fluid], and ultrastructural changes of myocardial cell were analysed. Systolic blood pressure at 10 and 30 minutes after reperfusion was higher in group III and IV than in group II [p<.05]. Also percent recovery of systolic blood pressure in group III [p<.01] and IV [p<.02] was higher than in group II. CK-MB isoenzyme level in effluent dialysates was peaked at 10 minutes after reperfusion, thereafter decreased in group II, III and IV. At 30 minutes after reperfusion, its level was lower in group III and IV than in group II[p<.05]. Adenine ring compound level in effluent dialysates increased till 10 minutes after reperfusion and progressively decreased. At 10 and 30 minutes after reperfusion, its level was lower in group III and IV than in group II without significance. Degree of myocardial damage was estimated by scoring of mitochondrial injury. Group I was within normal range and most severe injury was seen in group II. And the score of mitochondrial injury in group III and IV was lower than in group II. In conclusion, SOD and substrates[KMP solution] had protective effect on stunned myocardium. The microdialysis appratus was a good device for studying stunned myocardium, and cardiac microdialysis might be a unique technique for analysis of regional intramyocardial interstitial fluid.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.257-262
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• 2004

ErmSF is one of the ERM proteins which transfer the methyl group to A2058 in 23S rRNA to confer the resis­tance to MLS (macrolide-lincosamide-streptogramin B) antibiotics on microorganism. Unlike other ERM pro­teins, ErmSF contains long N-terminal end region (NTER), of which $25\%$ is composed of arginine that is known to interact with RNA well. Gradual deletion of NTER leaded us to the point where mutant protein lost much of activity in vivo. Overexpressed and purified mutant protein showed much reduced activity in vitro: $2\%$ activity relative to that of wild type protein. This fact suggests that this amino acid interact with RNA close to meth­ylatable adenine to locate it at an active site properly.

• BMB Reports
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• v.41 no.8
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• pp.604-608
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• 2008

1-Nitropyrene 4,5-oxide and 1-nitropyrene 9,10-oxide are oxidative metabolites that are responsible for the mutagenicity of 1-nitropyrene. In this study, the mutation spectra induced by oxidative metabolites in human cells were determined using a shuttle vector assay. The mutation frequencies induced by 1-nitropyrene 9,10-oxide were 2-3 times higher than those induced by 1-nitropyrene 4,5-oxide. The base substitutions induced by 1-nitropyrene 4,5-oxide were $G{\rightarrow}A$ transitions, $G{\rightarrow}C$ transversions, and $G{\rightarrow}T$ transversions. In the case of 1-nitropyrene 9,10-oxide, $G{\rightarrow}A$ transitions, $G{\rightarrow}T$ transversions, $A{\rightarrow}G$ transitions and $G{\rightarrow}C$ transversions were observed. Most base substitution mutations induced by oxidative metabolites occurred at the guanine sites in the supF gene. These sequence-specific hot spots were commonly identified as 5'-GA sequences for both metabolites. On the other hand, the sequence-specific hot spots at the adenine sites were identified as 5'-CAC sequences for 1-nitropyrene 9,10-oxide. These results suggest that the oxidative metabolites of 1-nitropyrene induce sequence-specific DNA mutations at the guanine and adenine sites at high frequency.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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• pp.373-382
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• 2015

Fura-2 analogs are ratiometric fluoroprobes that are widely used for the quantitative measurement of [$Ca^{2+}$]. However, the dye usage is intrinsically limited, as the dyes require ultraviolet (UV) excitation, which can also generate great interference, mainly from nicotinamide adenine dinucleotide (NADH) autofluorescence. Specifically, this limitation causes serious problems for the quantitative measurement of mitochondrial [$Ca^{2+}$], as no available ratiometric dyes are excited in the visible range. Thus, NADH interference cannot be avoided during quantitative measurement of [$Ca^{2+}$] because the majority of NADH is located in the mitochondria. The emission intensity ratio of two different excitation wavelengths must be constant when the fluorescent dye concentration is the same. In accordance with this principle, we developed a novel online method that corrected NADH and Fura-2-FF interference. We simultaneously measured multiple parameters, including NADH, [$Ca^{2+}$], and pH/mitochondrial membrane potential; Fura-2-FF for mitochondrial [$Ca^{2+}$] and TMRE for ${\Psi}_m$ or carboxy-SNARF-1 for pH were used. With this novel method, we found that the resting mitochondrial [$Ca^{2+}$] concentration was $1.03{\mu}M$. This $1{\mu}M$ cytosolic $Ca^{2+}$ could theoretically increase to more than 100 mM in mitochondria. However, the mitochondrial [$Ca^{2+}$] increase was limited to ${\sim}30{\mu}M$ in the presence of $1{\mu}M$ cytosolic $Ca^{2+}$. Our method solved the problem of NADH signal contamination during the use of Fura-2 analogs, and therefore the method may be useful when NADH interference is expected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.796-801
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• 2000

Kimchi is the Korean traditional food which is fermented properly from salted Korean cabbage of raddish with other various supplements. Kimchi therefore can be the major sources for various kinds of nutrients and other biological substances. The fermentation process accompanies with complicated reaction mechanism which bacteria, fungi and yeast are involved and they produced aroma, taste and bioactive components. To identify nucleoside, this study was conducted with freeze-dried mustard leaf, mustard leaf kimchi and fermented mustard leaf kimchi. Hexane, CH$_2$Cl$_2$, EtOAc and BuOH was used in order to extract their components. The isolated compounds I and II from mustard leaf and mustard leaf kimchi were identified as adenosine and uracil using UV, $^{1}H$-NMR, $^{13}C$-NMR and LC-MS, respectively. Compound I, II and nucleosides are the first report of its occurrence from mustard leaf and their kimchi, the standardized ratios of ingredients for kimchi were 10 of anchovy juice, 8 of red pepper powder, 3 of garlic, 1.5 of ginger, 6 of paste of glutinous rice. The nucleoside of mustard leaf and their kimchi was determined and compared. The order of nucleosides contents of mustard leaf was uridine>cytosine>uracil>adenine>guanosine>guanin, that of fresh mustard leaf kimchi was uridine>uracil>cytosine>guanine>adenosine>adenin>guanosine and that of fermented mustard leaf kimchi (5days at 15$^{\circ}C$) was guanine>adenine>adenosine>guanosine. The differences of nucleoside contents from those were due to various supplements and fermentation process.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.82-89
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• 2018

This study was carried out to understand phylogenetic relationships of the 30 mulberry cultivars converved in Korea based on the ITS rDNA region, and they were compared to 40 reference sequences from GenBank. The size and the G+C content of the ITS rDNA gene regions from the 30 Korean mulberry cultivars and 40 reference sequences varied from 612-630 bp and 58.19-61.62%, respectively. Based on the results of the comparative phylogenetic analysis of the ITS rDNA regions of the 30 Korean mulberry cultivars and 40 reference sequences, they were divided into three groups (Group 1, 2, and 3) and two subgroups (Group 1A and 1B within Group 1). The sequence lengths of the Korean mulberry cultivar numbers 1-26 and 27-30 were 615 bp and 616 bp, respectively. At 205 bp location of ITS1 rDNA region, the cultivar numbers 1-26 contain the nucleotide thymine but the cultivar numbers 27-30 contain the nucleotide adenine. In addition, the insertion of the nucleotide adenine at 206 bp location was found only in the four Korean mulberry cultivars (numbers 27-30). Based on these sequence information and phylogenetic result, the 30 Korean mulberry cultivars were identified as M. alba and M. australis. This study will contribute to the construction of genetic database constructions and accurate variety identifications for unidentified mulberry varieties in Korea.

• Mycobiology
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• v.36 no.2
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• pp.110-113
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• 2008

During a continuing search for antimicrobial substances from Korean native wild mushroom extracts, we found that the methanolic extract of the fruiting body of Clitocybe nebularis exhibited mild antifungal activity against pathogenic fungi. Therefore we evaluated the antifungal substances and other chemical components of the fruiting body of Clitocybe nebularis, which led to the isolation of nebularine, phenylacetic acid, purine, uridine, adenine, uracil, benzoic acid, and mannitol. Nebularine showed mild antifungal activity against Magnaphorthe grisea and Trichophyton mentagrophytes, and phenylacetic acid potently inhibited the growth of Pythium ultium and displayed moderate antifungal activity against Magnaphorthe grisea, Botrytis cinerea, and Trichophyton mentagrophytes. The other isolated compounds showed no antimicrobial activity.