• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1088-1092
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• 2009

A series of 2-alkyl or 2-arylthio-5,8-dimethoxy-1,4-naphthoquinones (2-Thio-DMNQ, 5a-s) and 2-alkylamino-5,8- dimethoxy-1,4-naphthoquinones (2-Amino-DMNQ, 6a-k) was synthesized and evaluated for their ACAT inhibitory activities. Among them, the 2-dodecylthio-DMNQ 5l and 2-isobutylamidoundodecylthio-DMNQ 5r showed the most potent ACAT inhibitory activities with $IC_{50}$ value of 22.8 and 24.4 ${\mu}M$, respectively. In a structure-activity relationship study, 2-thio-DMNQs with side chains of carbon number 11 $\sim$ 15 exhibited significant ACAT inhibitory activities.

• YAKHAK HOEJI
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• v.34 no.6
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• pp.422-428
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• 1990

2,3-Dibromo-1,4-naphthoquinone was reacted with p-aminobenzoic acid, 2-aminopyridine, 2-amino-4-metylpyridine, m-nitroaniline, sulfathiazol, p-chloroaniline, phenetidine and 2-bromo-3-(N-arylamino)-1,4-naphthoquinones($1{\sim}8$). 2,3-Epoxy-2,3-dihydro-1,4-naphthoquinone was also reacted with p-amonobenzoic acid, p-toluidine, p-chloroaniline, m-chloroaniline, m-nitroaniline, p-phenetidine, N,N-dimethyl-1,4-pheylenediamine as a ring opening and dehydogenation to form 2-hydroxy-3-(N-arylamino)-naphthoquinones ($9{\sim}16$) in good yield. These new compounds($1{\sim}16$) are expected to have a biological activities such as anticoagulant and cytotoxic.

• YAKHAK HOEJI
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• v.33 no.5
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• pp.273-279
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• 1989

2,3-Dichloro-1,4-naphthoquinone was reacted with o-fluoroaniline, p-sulfadiazine, p-acetoanline, N,N-dimethyl-1,4-phenylenediamine as a nucleophilic substitution to form 2-chloro-3-(N-arylamino)-1,4-naphthoquinones (1.-6.) in good yield. 2,3-Dibromo-1,4-naphthoquinone was also reacted with o-fluoroaniline, m-aminobenzoic acid, m-chloroaniline, morpholine, p-acetoaniline, N,N-dimethyl-1,4-phenylenediamine as a nucleophilic substitution to give 2-bromo-3-(N-arylamino)-1,4-naphthoquinones (7.-12.). These new compounds are expected to have a biological activities such as anticoagulant, cytotoxic.

• 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.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.400-404
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• 2005

Activity-guided fractionation of a hexane-soluble extract of the roots of Lithospermum erythrorhizon, using a mouse brain monoamine oxidase (MAO) inhibition assay, led to the isolation of two known naphthoquinones, acetylshikonin and shikonin, and a furylhydroquinone, shikonofuran E. These compounds were shown to inhibit MAO with $IC_{50}$ values of 10.0, 13.3, and $59.1 {\mu}M$, respectively. Although no specificity for MAO-A and MAO-B was shown by acetylshikonin and shikonin, a Lineweaver-Burk plot analysis indicated that the inhibition was competitive for both MAO-A and MAO-B activity.

• Proceedings of the Plant Resources Society of Korea Conference
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• 1996.09a
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• pp.8-15
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• 1996

• Applied Biological Chemistry
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• v.40 no.4
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• pp.352-356
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• 1997

To induce the phytoalexins in plant cell culture systems, we surveyed the antimicrobial activity following the feeding of five naphthoquinones in cell cultures of petunia. Among naphthoquinones treated, 2,5,7-trihydroxy-3-(5'-hydroxyhexyl)-1,4-naphthoquinone (3-OH NQ ) was most efficiently absorbed into the cells within 48 hr. The crude extracts of cells treated with 3-OH NQ showed a strong inhibition activity on spore germination of Aspergillus candidus $(MIC:\;32\;{\mu}g/ml)$, whereas the untreated cells showed no activity. The two active compounds, 4,2',4',${\beta}$-tetrahydroxychalcone and 4',7-dihydroxyflavone, were isolated from petunia cells treated with 3-OH NQ. The major phytoalexin, 4,2',4',${\beta}$-tetrahydroxychalcone, inhibited strongly the spore germination of A. candidus $(MIC:\;16\;{\mu}g/ml)$.

• YAKHAK HOEJI
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• v.44 no.2
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• pp.141-148
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• 2000

A new synthetic method of 6-(1-oxyalkyl)-5,8-dimethoxy-1,4-naphthoquinones was developed, 2-formyl-1,4,5,8-tetramethoxynaphthalene was oxidized to form 6-formyl-5,8-dimethoxy-1,4-naphthoquinone(DMNQ). This was selectively reduced and benzylated to produce 6-formyl-5,8-dimethoxy-1,4-dibenzyloxynaphthalene, to which various alkylmagnesium halide were added, followed by debenzylation and oxidation in sequence, yielding 6-(1-hydroxyalkyl)-DMNQ derivatives. 6-(1-hydroxyalkyl)-5,8-diethoxy-1,4-naphthalene (DENQ) derivatives were synthesized by similar procedure. 1'-OH of the naphthoquinone derivatives was acylated with various alkanoic acids to give 6-(1-acyloxyalkyl)-DMNQ or DENQ derivatives. TOPO-I inhibitory activity and cytotoxicity of DENQs were less potent than that of DMNQs. Among the DMNQ and DENQ analogues, the ones with alkyl group being heptyl were most potent in TOPO-I inhibition $IC_{50}$/; 30.1, 36.4 $\mu$M). DUNQ derivatives with a longer side chain exhibited a weaker cytotoxicity. A correlation between size of the alkyl side chain and cytotoxicity was not observed for DENQ derivatives. Acylation of 1'-hydroxyl group, in general, decreased both TOPO-I inhibitory activity and cytotoxicity T/C (%) values of the DENQ derivatives on S-180 intraperitoneal tumor were larger than those of DMNQ derivatives. Among the compounds synthesized,6-(1-hydroxyheptyl)-DENQ and 6-(1-hex-anoyloxyoctyl)-DMNQ showed the highest T/C values of 183% and 182%, respectively.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1619-1620
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• 2013

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1408-1410
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• 2004