• Bulletin of the Korean Chemical Society
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• v.19 no.12
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• pp.1337-1341
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• 1998

The charge transfer (CT) complex dyes between electron donor phenothiazine and electron acceptors namely, 2, 3-dichloro-1,4-naphtoquinone and 2,3-dichloro-5-nitro-1,4-naphtoquinone, were formed in the dichloromethane solution and electrochromic properties were studied using Bu4NC1O4 as supporting electrolyte. A 1 : 1 correspondence between the donor and acceptor molecules in the CT complex was found.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1233-1236
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• 2010

2,3-Dichloro-1,4-naphtoquinone 1 compound was reacted with octadecanethiol 2 in two different mole ratio. Compound 3 was obtained from the reaction of 1 and 2 in 1:2 mole/mole ratio. Compounds 7 and 8 were obtained from reaction of 1 and 2 in 1:1 mole/mole ratio and known compound 9 was synthesized as by-product in this reaction. Novel compounds 5a-e were obtained from reaction of 1 and related thiols 4a-e. Known compounds 6c and 6e were synthesized as by-product in this reaction. The structures of the compounds were characterized by elemental analysis, UV-vis, FTIR, $^1H$-NMR, $^{13}C$-NMR and Mass spectroscopies.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.263-268
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• 1992

In order to evaluate the antimicrobial effect of 2, 3-disubstitued-1, 4-naphtoquinone derivatives we newly synthesized several 2-bromo-3-(substituted)-1, 4 naphthoquninones. Amination reaction of 2, 3-dihalo-1, 4 naphthoquinones with aryl and aliphatic amines in ethanol gave 2-halo-3-(N-alkyl or N-aryl)1, 4-naphtoquinone derivatives (1a, b-10a, b) i 60% 90%) yield. These derivatives subjected to antibacterial and antifungal activities. in vitro, against Bacilllus subtilis ATCC 6633 Candida albicans 10231 and local, Psudomonas aeruginosa NCTC10490, Staphylococcus aureus ATCC 6538p. Escherichia coli NIHJ Aspergillus niger KCTC 1231, Tricophyton mentagrophytes KCTC 6085. Among these derivatives 1b, 6b and 7a showed the potent antibacterial activities 1b, 8b and 9b have derivatives, 1b, 6b and 7a showed the potent antibacterial activities. 1b, 8b and 9b have the antifungal activities. 1b is most effective in preventing the growth of Bacillus subtilis and Psudomonas aeruginosa. Candida albicans. Aspergillus niger. Tricophyton mentagrophytes. The several of these compounds demonstrated a broad spectrum of activities in vitro.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.537-538
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• 2005

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.619-627
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• 1997

It is known that 2-methyl-1,4-naphtoquinone(menadione, MD) induces hepatotoxicities both in vivo and in vitro. These toxic effects are believed to result from oxidative damages to hepatocytes by "active oxygen" species via one-electron reduction of the naphtoquinone. The ginsenoside(GS) is a complex mixture of individual ginsenosides which is known to produce a range of effects on the cardiovascular and central nervous systems. In particular, GS has an antioxidant effect. In this experiment we studied the effect of GS from red panax ginseng(red ginseng total saponin, RGTS) on free radical-induced liver injuries by MD. Administration of MD($150{\mu}M$) caused an increase in aspartate aminotransferase(AST) activities and lipid peroxidation, decrease in alkaline phosphatase(ALP) activities and total bilirubin levels in blood, caused depletion of GSH and changes of antioxidant enzyme(superoxide dismutase, catalase) activities are shown in liver tissue. Administration of RGTS restored the AST levels that increased by MD, but catalase showed no significant changes. RGTS also had an effect of restoring the GSH level and had some synergistic effects with SOD. These data suggest that RGTS may have some protective effects on liver injury which is related with the oxygen free radical.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.464-469
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• 2009

This study was conducted to find out environment-friendly disease control method to Alternaria blight caused by Alternaria panax of ginseng. For this study, 150 methanol extracts from medicinal plants were evaluated and the extract of Impatiens balsamina showed most strong antifungal activity against A. panax. The methanol extract of I. balsamina showed also stable antifungal activity against other ginseng pathogens such as Botrytis cinerea and Fusarium sp., when treated by heat or pH. In vivo, Alternaria blight incidence rate was low of 13% with the treatment of I. balsamina methanol extract compared to 35% of the non-treatment. The antifungal compound of I. balsamina was purified and identified by using a silica gel column chromatography, TLC and ESI-LC/MS/MS analysis. The compound which showed strong antifungal activity was identified as 2-methoxy-1,4-naphtoquinone ($C_{11}H_8O_3$).

• Animal cells and systems
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• v.11 no.1
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• pp.9-15
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• 2007

The naphthoquinone analog (2,3-dichloro-6,9-dihydroxy-1,4-naphtoquinone, NA) has an inhibitory effect on cdc25A protein phosphatase in vitro, which is responsible for G1/S transition during cell cycle. However, the exact mechanism inducing the growth inhibition is not understood. In this study, we investigated the regulatory mechanisms of growth arrest induced by NA, as a new potent inhibitor of cdc25A phosphatase, in human hepatocarcinoma SK-hep-1 cells. We found that NA induced the G1 arrest by perturbation of protein tyrosine dephosphorylation of Cdk2, which may be resulting from inhibition of cdc25A phosphatase. In addition, p21 was expressed in a p53-independent manner and participated in the NA-induced G1 arrest by inhibiting Cdk2 activity. Although the exact mechanism is not known, the p21 expression might be related to MAPK activation. From these results, we suggest that NA induces G1 arrest via inhibition of cdc25A and induction of p53-independent p21 expression in SK-Hep-1 cells.