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At least 19 recordsLinked to original sources
PubMed1978

In vitro and in vivo evaluation of the toxicity of 1,4-naphthoquinone and 1,2-naphthoquinone derivatives against Trypanosoma cruzi.

The toxic effect of lapachol, beta-lapachone and several 1,2-naphthoquinone derivatives on the growth, viability and infectivity of Trypanosoma cruzi were compared. beta-lapachone was the most active compound in vitro. No inhibition was observed in suspensions which contained inactivated foetal calf serum or rabbit haemoglobin solution. The infectivity of trypomastigotes in mice was not affected when cells were previously incubated with beta-lapachone or one of several other naphthoquinone derivatives in vitro in the presence of blood. It is suggested that beta-lapachone and the other compounds can be inactivated either by reduction in the presence of oxyhaemoglobin or by interaction with serum proteins. A beta-lapachone derivative, allyl-beta-lapachone, was not inactivated in the presence of blood and remained effective in suppressing trypomastigote infectivity.

Animals↗
PubMed1977

The sensitizing capacity of naturally occurring quinones. Experimental studies in guinea pigs. I. Naphthoquinones and related compounds.

Experimental studies on the sensitization capacity of naturally occurring naphthoquinones derived from plants and woods have been carried out with 6 compounds. With 4 of these substances (desoxylapachol, menadione, lapachenole andmacassar quinone) guinea pigs could be sensitized. Desoxylapachol, sensitizer from teak wood, and lapachenole, sensitizer from perobawood proved to be the most effective ones. Experiments with macassar quinone (oxidation product of a naphthalene constituent of macassar ebony) still demonstrate that even ortho-naphthoquinones are capable to induce contact allergy. Allergic cross reactions could be obtained with 9 out of 14 different napthoquinones. In animals sensitized with desoxylapachol menadione and lapachol showed the strongest eliciting effect. Furthermore the study demonstrated that the sensitizing effect of naphthoquinones depends on the length and position of the side chain attached to the quinoid ring as well as on the substitution of the carbon atom adjacent to the side chain bearing C-atom. With compounds substituted at this C-atom (e.g. position 3 of lapachol or didimethylallylnaphthoquinone) sensitization could not be obtained.

Allergens↗
PubMed1975

Potential bioreductive alkylating agents. 5. Antineoplastic activity of quinoline-5,8-diones, naphthazarins, and naphthoquinones.

A number of 2-chloromethyl and 2-bromomethyl derivatives of naphthoquinones, quinolinediones, and naphthazarins were designed and synthesized as potential bioreductive alkylating agents, and the antitumor activity of these compounds was assessed in mice bearing Sarcoma 180 ascites cells. The results indicated that, with the exception of 3-benzamido-2-chloromethyl-1,4-naphthoquinone, which was inactive, all newly synthesized naphthoquinones possessed strong antitumor activity against this neoplasm. 6,7-Bis(bromomethyl)quinoline-5,8-dione had moderate inhibitory activity against Sarcoma 180 at its optimal daily dosage level of 15 mg/kg. 3-Bromo-2-bromomethyl- and 3-bromo-2-chloromethylnaphthazarin produced a moderate extension of the life span of tumor-bearing mice; whereas, in contrast, 6,7-dimethyl analogs of these agents were inactive when employed in daily doses up to 40 mg/kg body weight.

Alkylating Agents↗
PubMed1975

Fungitoxicity of 1,4-naphthoquinones to Candida albicans and Trichophyton mentagrophytes.

Twenty-one substituted 1,4-naphthoquinones and five 8-quinolinols and copper(II) chelates were tested for antifungal activity against Candida albicans and Trichophyton mentagrophytes. Compounds containing electron-releasing or weak electron-withdrawing groups in the 2 and 3 positions of the 1,4-naphthoquinone ring were the most active against C. albicans at pH 7.0 in the presence of beef serum in the following order: 2-CH3O = 2,3-(CH3O)2 greater than 2-CH3 greater than 2-CH3S greater than 2-NH2 greater than 2,6-(CH3)2. For T. mentagrophytes under the same conditions the inhibitory 1,4-naphthoquinones contained the substituents 2-CH3O greater than 2,3-(CH3O)2 greater than 2-CH2S greater than 2-CH3 greater than 2-CH3(NaHSO3) greater than 2-NH2 greater than 2-C2H5S, 3-CH3 greater than 2,6-(CH3)2 greater than 2,3-CL2 greater than 5,8-(OH)2.

Antifungal Agents↗
PubMed1977

Synthesis of substituted benzoquinones and naphthoquinones with potential antituberculous activity.

Compounds were prepared through the reaction of benzoquinone, naphthoquinone and 2-methyl-1.4-naphthoquinone with several sulphonamides in common use. It is hoped that incorporation of these bacteriostatic agents with the high lipid solubility of the quinone used may afford a better bacteriostatic activity. Determination of the partition coefficient of some representative samples proved these compounds to have high lipid solubility.

Antitubercular Agents↗
PubMed1977

Studies on the amino groups of myosin ATPase. III. Effect of nucleotides on the fluorescence of beta-naphthoquinone-4-sulfonate bound to amino groups of myosin.

beta-Naphthoquinone-4-sulfonate was used for chemical modification of amino groups of myosin. The reagent was found to affect also the sulfhydryl groups if the reaction was not prevented by previous disulfide exchange with cystamine. When cystamine protection was employed the ATPase (ATP phosphohydrolase, EC3.6.1.3) activity was enhanced in the presence of Mg2+ and decreased in the presence of K+ or Ca2+, a pattern typical of myosin with blocked essential amino groups. On addition of ATP or ADP a blueshift was observed in the fluorescent emission spectrum of beta-naphthoquinone-4-sulfonate bound by myosin, presumably owing to conformational changes in the environment of essential amino groups induced by the binding of nucleotides.

Adenine Nucleotides↗
PubMed1977

Schistosomiasis mansoni: blockage of cercarial skin penetration by chemical agents: i. naphthoquinones and derivatives.

Skin penetration by Schistosoma mansoni cercariae may be blocked by 1,4-and 1,2-naphthoquinones applied topically. Of 23 naphthoquinone derivatives synthesized, 15 afforded almost complete protection when applied in solution to the tails of mice 24 hours before exposure to cercariae. On the basis of present evidence the 5-carbon atom side chain present in naturally occurring lapachol seems to be important for activity, and this is in accord with the previous observation that effective protective agents are liposoluble. Topically applied cercarial penetration inhibitors are presently the only prophylactic agents available for use in the field.

Administration, Topical↗
PubMed1975

Biosynthesis of flaviolin and 5,8-dihydroxy-2,7-dimethoxy-1,4-naphthoquinone.

Tracer experiments indicate a polyketide origin for the production of flaviolin (2,5,7-trihydroxy-1,4-naphthoquinone) by Aspergillus niger and 2,7-dimethoxynaphthazarin (5,8-dihydroxy-2,7-dimethoxy-1,4-naphthoquinone) by Streptomyces no. 12396. With the Streptomycete, a "solid state fermentation" technology was used for the incorporation studies. Radioactivity from shikimic acid was effectively incorporated into flaviolin; this conversion, however, proceeded by way of acetic acid. The latter stages of biosynthesis of 2,7-dimethoxynaphthazarin by the Streptomycete were shown to be as follows: flaviolin leads to mompain leads to 2,7-dimethoxynaphthazarin.

Acetates↗
PubMed1976

Potential bioreductive alkylating agents. 7. Antitumor effects of phenyl-substituted 2-chloromethyl-3-phenyl-1,4-naphthoquinones.

Functional groups such as nitro, chloro, bromo, and methoxy were introduced in the meta and para positions of the phenyl ring of the antineoplastic agent 2-chloromethyl-3-phenyl-1,4-naphthoquinone. Tests for tumor-inhibitory potency of these derivatives against Sarcoma 180 ascites cells in mice indicated that the para-substituted methoxyphenyl, chlorophenyl, and bromophenyl derivatives possessed antitumor activity comparable to that of the parent compound 2-chloromethyl-3-phenyl-1,4-naphthoquinone, whereas meta-substituted nitro and bromo derivatives were either inactive or only weakly active anticancer agents in this system.

Alkylating Agents↗
PubMed1976

Synthesis of 1.4-naphthoquinones-4-aryl(aroyl)hydrazones of potential antimicrobial activity.

The isolation of phthiocol (3-hydroxy-2-methyl-1.4-naphthoquinone) from the acetone-soluble fat fraction of tubercle bacilli [1, 2] and the confirmation that it had antituberculous activity against H-37 R.V. strain [20] in vitro and in mice [12], prompted the synthesis of some 2-alkyl-3-hydroxy-1.4-naphthoquinone-4-aryl(aroyl)hydrazones as possible tuberculostatic agents.

Anti-Infective Agents↗
PubMed1976

Anticoagulant activity of a naphthoquinone analog of vitamin K and an inhibitor of coenzyme Q10- enzyme systems.

Synthetic 2-hydroxy-3-h-dodecylmercapto-1,4-naphthoquinone is an analog of both vitamin K1 and coenzyme Q10. This naphthoquinone analog is an effective inhibitor of coenzyme Q10-enzymes of mammalian mitochondria, which are components of electron transfer mechanisms of respiration and coupled oxidative phosphorylation. This analog increased the prothrombin time in rats when it was administered orally or parenterally. Vitamin K1 reversed the prothrombin time increase, but that form of coenzyme Q, hexahydrocoenzyme Q4, which has the same phytyl side chain as vitamin K1, did not reverse the increase, constituting the biological differentiation between vitamin K and coenzyem Q. Two benzoquinone analogs of coenzyme Q10, 5-n-octadecylmercapto-2,3-dimethoxy-1,4-benzoquinone and 5-beta-naphthylmercapto-2,3-dimethoxy-1,4-benzoquinone, the latter being a strong inhibitor of coenzyme Q10-enzymes, did not increase the prothrombin time under comparable conditions.

Animals↗
PubMed1978

Ultrastructural alterations and peroxide formation induced by naphthoquinones in different stages of Trypanosoma cruzi.

Addition of beta-lapachone, an o-naphthoquinone with bactericidal, cytotoxic, and trypanocidal activities, to Trypanosoma cruzi epimastigote and amastigote stages induced the release of O2- and H2O2 from the whole cells into the suspending medium. In the presence of reduced nicotinamide adenine dinucleotide as reductant beta-lapachone was also able to stimulate O2- and H2O2 production by homogenates of these stages. Electron micrographs showed that in beta-lapachone-treated amastigotes and trypomastigotes, the chromatin is arranged in patches, clearly differing from the normal pattern of chromatin distribution. Alterations of the nuclear, mitochondrial, and cytoplasmic membranes, as well as swelling of the mitochondria were also observed.

Animals↗
PubMed1977

Separation of naphthoquinones and lipophilic vitamins by gel and thin-layer chromatography.

A separation of naphthoquinones on silica gel and on silica gel impregnated with polyethylene glycol 200 by thin-layer chromatography was compared with gel permeation chromatography (GPC) on styrene-divinylbenzene copolymer S-832-gel using tetrahydrofuran as mobile phase. Factors affecting the separations attainable are discussed, and it is concluded that GPC is a suitable method for the determination of K vitamins in natural materials.

Chromatography, Gel↗
PubMed1978

Discriminant analysis and structure-activity relationships. 1. Naphthoquinones.

Discriminant analysis has been used to study the data for naphthoquinones as antitumor agents in three different animal tumor systems. In each case the most significant variables for classifying the compounds into two groups according to their antitumor activities were determined by a stepwise procedure. The usefulness of discriminant analysis in the design of drugs is discussed.

Animals↗
PubMed1977

Synthesis and antiallergic activity of 2-hydroxy-3-nitro-1,4-naphthoquinones.

A selection of novel 2-hydroxy-3-nitro-1,4-naphthoquinones are shown to be potent inhibitors of rat passive cutaneous anaphylaxis (PCA) and to have highest potency with alkyl substitution at both C-6 and C-7. The most potent compounds were 7c and 7e which produced a 50% inhibition in the rat PCA test at doses of about 10 micrometerM/kg following subcutaneous administration and showed activity after oral administration. Related 4-hydroxy-3-nitro-2(1H)-naphthalenones had no effect on rat PCA in doses up to 500 micrometerM/kg.

Animals↗
PubMed1978

A naphthoquinone adsorbent for affinity chromatography of human dihydropteridine reductase.

1. A 1,2-naphthoquinone adsorbent is described which allows simple purification of dihydropteridine reductase directly from crude extract. 2. The native molecular weight indicates that a tetramer structure of the species is isolated by this method; this is unusual and possibly reflects the capacity of the procedure to preserve the native state of the enzyme.

Animals↗
PubMed1979

No strict coupling of vitamin K1 (2-methyl-3-phytyl-1,4-naphthoquinone)-dependent carboxylation and vitamin K1 epoxidation in detergent-solubilized microsomal fractions from rat liver.

NAD(P)H dehydrogenase ('DT-diaphorase', EC 1.6.99.2) and vitamin K epoxidase were removed by affinity chromatography from detergent-solubilized microsomal fractions. Thereby the microsomal fractions normally carrying out vitamin K1-dependent carboxylation of the microsomal precursor proteins of the prothrombin complex were inactivated. Purified NAD(P)H dehydrogenase added to this system restored carboxylation in the presence of vitamin K1 (2-methyl-3-phytyl-1,4-naphthoquinone) plus NADH. Vitamin K1 hydroquinone (2-methyl-3-phytyl-1,4-naphthoquinol) had no effect, in contrast with its effect in the intact system, where it can substitute for vitamin K1 plus NADH. The ability of NAD(P)H dehydrogenase to restore carboxylation in a system without vitamin K epoxidase activity shows that there is no obligatory coupling of the vitamin K1-dependent carboxylation with vitamin K1 epoxidation. These results suggest that the form of vitamin K1 that is active in the carboxylation reaction can be produced independently in two reactions: by NAD(P)H dehydrogenase in the reduction of the quinone and by vitamin K epoxidase in the epoxidation of the hydroquinone.

Animals↗