• Archives of Pharmacal Research
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• v.27 no.9
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• pp.893-900
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• 2004

2- or 6-Substituted BZT-N derivatives were synthesized, and their cytotoxic activity against can-cer L1210 and SNU-1 cells was examined. The antitumor action was also assessed in mice bearing S-180 cells in peritoneal cavity. In a comparison, it was found that 6-substituted BZT-N derivatives exhibited higher potencies in both bioactivities than 2-substituted BZT-N derivatives against L1210 cells in in vitro and S-180 in vitro tests exception of compound 36. Interestingly, it was observed that 2-substituted compound 36, which has methyl group at RI position, exhib-ited a better antitumor activity than 6-substituted compounds against L1210 and SNU-1 in vitro. The EDso value of 2-substituted compound 36 against L1210 was found to be comparable to the EDso value of adriamycin and was even better against the solid cancer cell line SNU-1. It was also observed that 2-substituted compound 36 showed better antitumor activity in mice bearing S-180 cells in the peritoneal cavity. The T/C (％) value of 2-substituted compound 36 was simi-lar to that of adriamycin. Quantitative structure-activity relationship (QSAR) tests reveal that the experimental E $D_{50}$ values against SNU-1 closely correlate with both the calculated HOMO ener-gies ( $E_{HOMO}$) and the measured H-NMR chemical shift of 3-H ($\delta$$_{H}$). The results suggests that a compound having higher $E_{HOMO}$ and $\delta$$_{H}$ values usually should have a lower E $D_{50}$ (SNU-1) value.lue.lue.lue.

• BMB Reports
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• v.32 no.2
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• pp.127-132
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• 1999

The NAD(P)H-quinone oxidoreductase (EC 1. 6. 99. 2) was purified from S. cerevisiae. The native molecular weight of the enzyme is approximately 111 kDa and is composed of five identical subunits with molecular weights of 22 kDa each. The optimum pH of the enzyme is pH 6.0 with 1,4-benzoquinone as a substrate. The apparent $k_m$ for 1,4-benzoquinone and 1,4- naphthoquinone are 1.3 mM and $14.3\;{\mu}M$, respectively. Its activity is greatly inhibited by $Cu^{2+}$ and $Hg^{2+}$ ions, nitrofurantoin, dicumarol, and Cibacron blue 3GA. The purified NAD(P)H-quinone oxidoreductase was found capable of reducing aromatic nitroso compounds as well as a variety of quinones, and can utilize either NADH or NADPH as a source of reducing equivalents. The nitroso reductase activity of the purified NAD(P)H-quinone oxidoreductase is strongly inhibited by dicumarol.

• Molecules and Cells
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• v.26 no.4
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• pp.362-367
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• 2008

We identified a 1,134-bp putative type III polyketide synthase from the sequence analysis of Streptomyces peucetius ATCC 27952, named Sp-RppA, which is characterized as 1,3,6,8-tetrahydroxynaphthalene synthase and shares 33% identity with SCO1206 from S. coelicolor A3(2) and 32% identity with RppA from S. griseus. The 1,3,6,8-tetrahydroxynaphthalene synthase is known to catalyze the sequential decarboxylative condensation, intramolecular cyclization, and aromatization of an oligoketide derived from five units of malonyl-CoA to give 1,3,6,8-tetrahydroxynaphthalene, which spontaneously oxidizes to form 2,5,7-trihydroxy-1,4-naphthoquinone (flaviolin). In this study, we report the in vivo expression and in vitro synthesis of flaviolin from purified gene product (Sp-RppA).

• Archives of Pharmacal Research
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• v.15 no.2
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• pp.138-141
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• 1992

The new N-aryl-benz[f]-indole-4, 9-dione derivatives were synthesized via in tramolecular cyclization when triethylamine was employed as a base for the reaction of 2-chloro-3-$(\alpha$-cyano-$\alpha$-ethoxycarbonyl-methyl)-1, 4-naphthoquinone and arylamines.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.350.3-351
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• 2002

2-Arylthio-, 2-arylthio-5-methoxy-, 2, 3-bisarylthio-juglones and 2, 3-bisarylthio-5, 8-dimethoxy-1, 4-naphthoquinones were newly systhesized for the evaluation of antifungal activities. These derivatives were prepared by methylation of juglone and 2, 3-dichloro-5, 8-dihydroxy-1, 4-naphthoquinone. and by resioselective nucleophilic subsitution with arylthiols. All compounds were tested in vitro for their growth inhibitory activities against pathogenic fungi by the standard method. The MIC values were determined by comparison to flucytosine as a fungicidal standard agent. In general. In general. most juglone derivatives shows in vitro antifungal activities. Among them. 2-arylthio-5-methoxy-juglones showed most potent antifungal activities against all pathogenic fungi.

• Natural Product Sciences
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• v.22 no.3
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• pp.220-224
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• 2016

Anti-Helicobacter pylori activity guided fractionation led to the isolation of five anthraquinones, two stilbenes and one naphthoquinone from the EtOAc fraction of Polygonum cuspidatum, using silica gel column chromatography, Sephadex-LH20, MPLC and recrystallization. The chemical structures were identified to be physcion (1), emodin (2), anthraglycoside B (3), trans-resveratrol (4), anthraglycoside A (5), polydatin (6), 2-methoxy-6-acetyl-7-methyljuglone (7) and citreorosein (8) by UV, $^1H$-NMR, $^{13}C$-NMR and mass spectrometry. Anti-Helicobacter pylori activity including MIC values of each compound was evaluated. All of the isolates exhibited anti-H. pylori activity of which MIC values were lower than that of a positive control, quercetin. Compounds 2 and 7 showed potent growth inhibitory activity. Especially, a naphthoquinone, compound 7 displayed most potent antibacterial activity with $MIC_{50}$ value of $0.30{\mu}M$ and $MIC_{90}$ value of $0.39{\mu}M$. Although anti-H. pylori activity of this plant was previously reported, this is the first report on that of compounds isolated from this species. From these findings, P. cuspidatum roots or its isolates may be useful for H. pylori infection and further study is needed to elucidate mechanism of action.

• 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.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.247.2-247.2
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• 2002

A synthetic naphthoquinone alkaloid. 2-amino-3-ethoxycarbonyl-l-methyl pyrolo (3,2-b) naphtho-4,9-dione (compound 1), showed a potent cytotoxicity in a panel of cancer cell lines with an IC50 ranged from 0.1 to 0.3 microgram/mL. Prompted by a potent cytotoxic activity, the mechanism action study was performed with cultured A549 of human lung cancer cells. Flow cytometric G2-M cell cycle arrest and microscopic investigation was also characterized with apoptotic morphological features. (omitted)

• Archives of Pharmacal Research
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• v.24 no.1
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• pp.35-38
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• 2001

Various analogues of 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) such as 2- or 6-(1-hydro-xyiminoalkyl)-DMNQs were prepared and evaluated for the antitumor action. (1-Hydroxyiminoalkyl)-DMNQ derivatives expressed greater antitumor action than (1 -hydroxyalkyl)- or acyl-DMNQ derivatives. Moreover, 6-(1-hydroxyiminoalkyl)-DMNQ derivatives expressed higher anti-tumor action than 2-sudstituted ones, suggestive of a steric effect. Some of 6-(1-propyloxyalkyl)-DMNQ derivatives with an alkyl group of butyl to octyl moiety showed T/C values of > 400 %.

• Archives of Pharmacal Research
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• v.24 no.3
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• pp.190-193
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• 2001

Various analogues of 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) such as 2- or 6-(1-hydroxyiminoalkyl)-DMNQs were prepared and evaluated for the antitumor action. (1 -Hydroxyiminoalkyl)-DMNQs derivatives expressed greater antitumor action than (1-hydroxyalkyl) - or acyl-DMNQ derivatives. Moreover, 6-(1-hydroxyiminoalkyl)-DMNQ derivatives expressed higher antitumor action than 2-substituted ones, suggestive of a steric effect. Some of 6-(1-propyloxyalkyl)-DMNQ derivatives with an alkyl group of butyl to octyl moiety showed T/C values of >400%