Journal articles: 'Naphthoquinone'

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Córdova-Rivas, Sergio, Jorge Gustavo Araujo-Huitrado, Ernesto Rivera-Avalos, Ismailia L. Escalante-García, Sergio M. Durón-Torres, Yamilé López-Hernández, Hiram Hernández-López, Lluvia López, Denisse de Loera, and Jesús Adrián López. "Differential Proliferation Effect of the Newly Synthesized Valine, Tyrosine and Tryptophan–Naphthoquinones in Immortal and Tumorigenic Cervical Cell Lines." Molecules 25, no. 9 (April 28, 2020): 2058. http://dx.doi.org/10.3390/molecules25092058.

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We previously showed that microwave assisted synthesis is the best method for the synthesis of naphthoquinone amino acid and chloride-naphthoquinone amino acid derivatives by a complete evaluation of reaction conditions such as stoichiometry, bases, and pH influence. Following the same strategy, we synthesized chloride and non-chloride tyrosine, valine, and tryptophan-naphthoquinones achieving 85–95%, 80–92%, and 91–95% yields, respectively. The cyclic voltammetry profiles showed that both series of naphthoquinone amino acid derivatives mainly display one redox reaction process. Overall, chloride naphthoquinone amino acid derivatives exhibited redox potential values (E1/2) more positive than non-chloride compounds. The six newly synthesized compounds were tested in HPV positive and negative as well as in immortal and tumorigenic cell lines to observe the effects in different cellular context simulating precancerous and cancerous status. A dose-response was achieved to determine the IC50 of six newly synthesized compounds in SiHa (Tumorigenic and HPV16 positive), CaLo (Tumorigenic and HPV18 positive), C33-A (Tumorigenic and HPV negative) and HaCaT (Keratinocytes immortal HPV negative) cell lines. Non-chloride tryptophan-naphthoquinone (3c) and chloride tyrosine-naphthoquine (4a) effects were more potent in tumorigenic SiHa, CaLo, and C33-A cells with respect to non-tumorigenic HaCaT cells. Interestingly, there seems to be a differential effect in non-chloride and chloride naphthoquinone amino acid derivatives in tumorigenic versus non tumorigenic cells. Considering all naphthoquinone amino acid derivatives that our group synthesized, it seems that hydrophobic and aromatic amino acids have the greatest effect on cell proliferation inhibition. These results show promising compounds for cervical cancer treatment.

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Buffinton, G. D., K. Öllinger, A. Brunmark, and E. Cadenas. "DT-diaphorase-catalysed reduction of 1,4-naphthoquinone derivatives and glutathionyl-quinone conjugates. Effect of substituents on autoxidation rates." Biochemical Journal 257, no. 2 (January 15, 1989): 561–71. http://dx.doi.org/10.1042/bj2570561.

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DT-diaphorase catalysed the reduction of 1,4-naphthoquinones with hydroxy, methyl, methoxy and glutathionyl substituents at the expense of reducing equivalents from NADPH. The initial rates of quinone reduction did not correlate with either the half-wave reduction potential (E1/2) value (determined by h.p.l.c. with electrochemical detection against an Ag/AgCl reference electrode) or the partition coefficient of the quinones. After their reduction by DT-diaphorase the 1,4-naphthoquinone derivatives autoxidized at distinct rates, the extent of which was influenced by the nature of the substituents. Thus for the 1,4-naphthoquinone series the following order of rate of autoxidation was found: 5-hydroxy-1,4-naphthoquinone greater than 3-glutathionyl-1,4-naphthoquinone greater than 5-hydroxy-3-glutathionyl-1,4-naphthoquinone greater than 1,4-naphthoquinone greater than 2-hydroxy-1,4-naphthoquinone. For the 2-methyl-1,4-naphthoquinone (menadione) series the following order was observed: 5-hydroxy-2-methyl-1,4-naphthoquinone greater than 3-glutathionyl-5-hydroxy-2-methyl-1,4-naphthoquinone greater than 3-glutathionyl-2-methyl-1,4-naphthoquinone greater than 2-methyl-1,4-naphthoquinone greater than 3-hydroxy-2-methyl-1,4-naphthoquinone. The autoxidized naphthohydroquinone derivatives were re-reduced by DT-diaphorase, thus closing a cycle of enzymic reduction in equilibrium autoxidation. This was expressed as an excess of NADPH oxidized over the initial concentration of quinone present as well as H2O2 formation. These findings demonstrate that glutathionyl conjugates of 1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone and those of their respective 5-hydroxy derivatives are able to act as substrates for DT-diaphorase and that they also autoxidize at rates higher than those for the unsubstituted parent compounds. These results are discussed in terms of the cellular role of DT-diaphorase in the reduction of hydroxy- or glutathionyl-substituted naphthoquinones as well as the further conjugation of these hydroquinones with glucuronide or sulphate within the cellular milieu, thereby facilitating their disposal from the cells.

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Liu, Rui, and Hong Li. "Structural Modification of 1,4-Naphthoquinone Molecule for Application in Dyeing." Advanced Materials Research 781-784 (September 2013): 979–82. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.979.

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Quinones are useful compounds as dye compounds and the 1,4-naphthoquinone structure constitutes an essential part of these classes of compounds. The process in constructing 1,4-naphthoquinone for possible screening as dyestuff is described, starting from 1,4-naphthoquinone and hydroxy acid. It provides a novel methodology for the synthesis of the 5-nitro-2-substituted 1,4-naphthoquinones. The products were characterized by IR and1H NMR.

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Rudnicka, Małgorzata, Michał Ludynia, and Waldemar Karcz. "Effects of Naphthazarin (DHNQ) Combined with Lawsone (NQ-2-OH) or 1,4-Naphthoquinone (NQ) on the Auxin-Induced Growth of Zea mays L. Coleoptile Segments." International Journal of Molecular Sciences 20, no. 7 (April 11, 2019): 1788. http://dx.doi.org/10.3390/ijms20071788.

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Naphthoquinones, plants secondary metabolites are known for their antibacterial, antifungal, anti-inflammatory, anti-cancer and anti-parasitic properties. The biological activity of naphthoquinones is connected with their ability to generate reactive oxygen species and to modify biological molecules at their nucleophilic sites. In our research, the effect of naphthazarin (DHNQ) combined with 2-hydroxy-1,4-naphthoquinone (NQ-2-OH) or 1,4-naphthoquinone (1,4-NQ) on the elongation growth, pH changes of the incubation medium, oxidative stress and redox activity of maize coleoptile cells were investigated. This paper describes experiments performed with maize (Zea mays L.) coleoptile segments, which is a classical model system to study plant cell elongation growth. The data presented clearly demonstrate that lawsone and 1,4-naphthoquinone combined with naphthazarin, at low concentrations (1 and 10 nM), reduced the endogenous and IAA-induced (Indole-3-Acetic Acid) elongation growth of maize coleoptile segments. Those changes in growth correlated with the proton concentration in the incubation medium, which suggests that the changes in the growth of maize coleoptile segments observed in the presence of naphthoquinones are mediated through the activity of PM H+-ATPase. The presence of naphthoquinones induced oxidative stress in the maize coleoptile tissue by producing hydrogen peroxide and causing changes in the redox activity. Moreover, the incubation of maize segments with both naphthoquinones combined with naphthazarin resulted in lipid peroxidation and membrane damage. The regulation of PM H+-ATPase activity, especially its inhibition, may result from two major types of reaction: first, a direct interaction between an enzyme and naphthoquinone, which leads to the covalent modification of the protein thiols and the generation of thioethers, which have been found to alter the activity of the PM H+-ATPases; second, naphthoquinones induce reactive oxygen species (ROS) production, which inhibits PM H+-ATPases by increasing cytosolic Ca2+. This harmful effect was stronger when naphthazarin and 1,4-naphthoquinone were added together. Taking these results into account, it can be suggested that by combining naphthoquinones in small quantities, an alternative to synthetic pesticides could be developed.

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Ma, Qinge, Rongrui Wei, and Zhipei Sang. "Structural Characterization and Hepatoprotective Activity of Naphthoquinone From Cucumis bisexualis." Natural Product Communications 15, no. 1 (January 1, 2020): 1934578X2090289. http://dx.doi.org/10.1177/1934578x20902898.

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Three new naphthoquinones, namely 5,8-dihydroxy-7′-isopropyl-furan ring-1″-prenyl-naphthoquinone (1), 5,8-dihydroxy-7′-propenyl-furan ring-1″-isopropanol-naphthoquinone (2), and 5,8-dihydroxy-7′-isopropanol-furan ring-1″-(5″-hydroxyphenyl)-naphthoquinone (3), along with 10 known naphthoquinone derivatives (4-13) were isolated from Cucumis bisexualis for the first time. All the compounds were elucidated on the basis of spectroscopic data analysis and chemical evidence. Compounds (1-13) were evaluated for their hepatoprotective activites on human L-O2 cells. Among them, compounds 1, 4, and 8 exhibited significant promotion effects on the proliferation of L-O2 cells.

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Rivera-Ávalos, Ernesto, Denisse de Loera, Jorge Gustavo Araujo-Huitrado, Ismailia Leilani Escalante-García, Miguel Antonio Muñoz-Sánchez, Hiram Hernández, Jesús Adrián López, and Lluvia López. "Synthesis of Amino Acid–Naphthoquinones and In Vitro Studies on Cervical and Breast Cell Lines." Molecules 24, no. 23 (November 25, 2019): 4285. http://dx.doi.org/10.3390/molecules24234285.

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We performed an extensive analysis about the reaction conditions of the 1,4-Michael addition of amino acids to 1,4-naphthoquinone and substitution to 2,3-dichloronaphthoquinone, and a complete evaluation of stoichiometry, use of different bases, and the pH influence was performed. We were able to show that microwave-assisted synthesis is the best method for the synthesis of naphthoquinone–amino acid and chloride–naphthoquinone–amino acid derivatives with 79–91% and 78–91% yields, respectively. The cyclic voltammetry profiles showed that both series of naphthoquinone–amino acid derivatives mainly display one quasi-reversible redox reaction process. Interestingly, it was shown that naphthoquinone derivatives possess a selective antitumorigenic activity against cervix cancer cell lines and chloride–naphthoquinone–amino acid derivatives against breast cancer cell lines. Furthermore, the newly synthetized compounds with asparagine–naphthoquinones (3e and 4e) inhibited ~85% of SiHa cell proliferation. These results show promising compounds for specific cervical and breast cancer treatment.

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Ríos, David, Jaime A. Valderrama, Miriam Cautin, Milko Tapia, Felipe Salas, Angélica Guerrero-Castilla, Giulio G. Muccioli, Pedro Buc Calderón, and Julio Benites. "New 2-Acetyl-3-aminophenyl-1,4-naphthoquinones: Synthesis and In Vitro Antiproliferative Activities on Breast and Prostate Human Cancer Cells." Oxidative Medicine and Cellular Longevity 2020 (September 26, 2020): 1–11. http://dx.doi.org/10.1155/2020/8939716.

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The reaction of 2-acyl-1,4-naphthoquinones with N,N-dimethylaniline and 2,5-dimethoxyaniline, promoted by catalytic amounts of CeCl3·7H2O under “open-flask” conditions, produced a variety of 2-acyl-3-aminophenyl-1,4-naphthoquinones structurally related to the cytotoxic 2-acetyl-3-phenyl-1,4-naphthoquinone, an inhibitor of the heat shock chaperone protein Hsp90. The members of the 2-acyl-3-aminophenyl-1,4-naphthoquinone series were isolated in good yields (63-98%). The cyclic voltammograms of the 2-acyl-3-aminophenyl-1,4-naphthoquinone exhibit two one-electron reduction waves to the corresponding radical-anion and dianion and two quasireversible oxidation peaks. The first and second half-wave potential values (E1/2) of the members of the series are sensitive to the push-pull electronic effects of the substituents in the naphthoquinone scaffold. Furthermore, the in vitro antiproliferative properties of these new quinones were evaluated on two human cancer cells DU-145 (prostate) and MCF-7 (mammary) and a nontumorigenic HEK-293 (kidney) cell line, using the MTT colorimetric method. Two members, within the series, exhibited interesting cytotoxic activities on human prostate and mammary cancer cells.

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Kumbhar, A. S., S. B. Padhye, Jitender, and R. K. Kale. "Naturally Occurring Hydroxy Napthoquinones and Their Iron Complexes as Modulators of Radiation Induced Lipid Peroxidation in Synaptosomes." Metal-Based Drugs 4, no. 5 (1997): 279–85. http://dx.doi.org/10.1155/mbd.1997.279.

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The modulation of radiation induced lipid peroxidation in synaptosomes by iron (II) and iron (III) complexes of two naturally occurring and therapeutically relevant naphthoquinones viz. 5,hydroxy-1,4 naphthoquinone; juglone and 2,hydroxy-1,4 naphthoquinone; lawsone, have been studied. At lower concentrations the complexes enhance lipid peroxidation predominantly through redox cycling as observed for Fe(II)- juglonate while at higher concentrations the complexes tend to limit lipid peroxidation through fast recombinations.

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Raspotnig, Günther, Felix Anderl, and Ronald M. Clouse. "The scent gland chemistry of neogoveid cyphophthalmids (Opiliones): an unusual methyljuglone from Metasiro savannahensis." Chemoecology 29, no. 5-6 (September 26, 2019): 189–97. http://dx.doi.org/10.1007/s00049-019-00288-y.

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Abstract While the chemistries of scent gland secretions from a few selected species of three families of Cyphophthalmi, namely Sironidae, Pettalidae, and Stylocellidae, have already been reported and found to consist of complex blends of naphthoquinones and methyl ketones, nothing is known about the other families. We here report on the secretions of Metasiro savannahensis Clouse and Wheeler (Zootaxa 3814:177–201, 2014), a first representative of the family Neogoveidae. The secretions from males, females and one juvenile were extracted and analyzed by gas chromatography–mass spectrometry. Twenty-five compounds were identified, all of which belong to the chemical classes of naphthoquinones and methyl ketones, confirming a hypothesized chemical uniformity of cyphophthalmid exudates. One major naphthoquinone compound, however, was new for cyphophthalmids and for arthropod exocrine secretions in general: a methyljuglone isomer, 6-methyljuglone (= 6-MJ; iupac name: 5-hydroxy-6-methyl-1,4-naphthoquinone), amounted for about 20% of the secretion and was eventually identified by synthesis. Hydroxy-naphthoquinones and their derivatives are known to possess a variety of antibiotic effects, probably enhancing the antimicrobial/antifungal potential of the Metasiro-secretion. Currently, without further data on neogoveids, the compound represents a chemical autapomorphy of M. savannahensis, and—just as the strange chloro-naphthoquinones of Sironidae and Pettalidae—adds to the repertoire of unusual naphthoquinone compounds across the Cyphophthalmi.

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de Souza, Acácio S., Ruan Carlos B. Ribeiro, Dora C. S. Costa, Fernanda P. Pauli, David R. Pinho, Matheus G. de Moraes, Fernando de C. da Silva, Luana da S. M. Forezi, and Vitor F. Ferreira. "Menadione: a platform and a target to valuable compounds synthesis." Beilstein Journal of Organic Chemistry 18 (April 11, 2022): 381–419. http://dx.doi.org/10.3762/bjoc.18.43.

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Naphthoquinones are important natural or synthetic compounds belonging to the general class of quinones. Many compounds in this class have become drugs that are on the pharmaceutical market for the treatment of various diseases. A special naphthoquinone derivative is menadione, a synthetic naphthoquinone belonging to the vitamin K group. This compound can be synthesized by different methods and it has a broad range of biological and synthetic applications, which will be highlighted in this review.

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Zeng, Fan-Lin, Xiao-Lan Chen, Shuai-Qi He, Kai Sun, Yan Liu, Rui Fu, Ling-Bo Qu, Yu-Fen Zhao, and Bing Yu. "Copper-catalyzed one-pot three-component thioamination of 1,4-naphthoquinone." Organic Chemistry Frontiers 6, no. 9 (2019): 1476–80. http://dx.doi.org/10.1039/c9qo00091g.

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Valderrama, Jaime A., Mónica Cabrera, Julio Benites, David Ríos, Ricardo Inostroza-Rivera, Giulio G. Muccioli, and Pedro Buc Calderon. "Synthetic approaches and in vitro cytotoxic evaluation of 2-acyl-3-(3,4,5-trimethoxyanilino)-1,4-naphthoquinones." RSC Advances 7, no. 40 (2017): 24813–21. http://dx.doi.org/10.1039/c7ra03238b.

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2-Acyl-1,4-naphthoquinones react with 3,4,5-trimethoxyaniline, under aerobic conditions, to give benzophenanthridinequinone, benzocarbazole and 2-acyl-3-(3,4,5-trimethoxyanilino)-1,4-naphthoquinone derivatives.

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Medina, L. F. C., P. F. Hertz, V. Stefani, J. A. P. Henriques, A. Zanotto-Filho, and A. Brandelli. "Aminonaphthoquinone induces oxidative stress inStaphylococcus aureus." Biochemistry and Cell Biology 84, no. 5 (October 2006): 720–27. http://dx.doi.org/10.1139/o06-087.

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The biological activity of 5-amino-8-hydroxy-1,4-naphthoquinone (ANQ) on Staphylococcus aureus was investigated in comparison with the unsubstituted 1,4-naphthoquinone (NQ). Complete inhibition of microbial growth was observed with ANQ and NQ at 50 and 10 µg/mL, respectively. The antibacterial effect of naphthoquinones decreased in the presence of sodium ascorbate, but the superoxide scavenger 4,5-dihydroxy-1,3-benzene-disulfonic acid (Tiron) was able to protect S. aureus only from the harmful effect of ANQ. Naphthoquinones blocked oxygen uptake and induced cyanide-insensitive oxygen consumption. When combining rotenone or salicylhydroxamic acid with ANQ or NQ, a slight decrease in respiratory activity was observed. Assays in the presence of naphthoquinones induced an increase of lipid peroxidation in S. aureus, as determined by thiobarbituric acid reactive substances. These results showed that 1,4-naphthoquinones effectively act as electron acceptors and induce an increase in reactive oxygen species that are toxic to S. aureus cells.

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Navarro-Tovar, Gabriela, Sarai Vega-Rodríguez, Elisa Leyva, Silvia Loredo-Carrillo, Denisse de Loera, and Lluvia Itzel López-López. "The Relevance and Insights on 1,4-Naphthoquinones as Antimicrobial and Antitumoral Molecules: A Systematic Review." Pharmaceuticals 16, no. 4 (March 27, 2023): 496. http://dx.doi.org/10.3390/ph16040496.

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Natural product derivatives are essential in searching for compounds with important chemical, biological, and medical applications. Naphthoquinones are secondary metabolites found in plants and are used in traditional medicine to treat diverse human diseases. Considering this, the synthesis of naphthoquinone derivatives has been explored to contain compounds with potential biological activity. It has been reported that the chemical modification of naphthoquinones improves their pharmacological properties by introducing amines, amino acids, furan, pyran, pyrazole, triazole, indole, among other chemical groups. In this systematic review, we summarized the preparation of nitrogen naphthoquinones derivatives and discussed their biological effect associated with redox properties and other mechanisms. Preclinical evaluation of antibacterial and/or antitumoral naphthoquinones derivatives is included because cancer is a worldwide health problem, and there is a lack of effective drugs against multidrug-resistant bacteria. The information presented herein indicates that naphthoquinone derivatives could be considered for further studies to provide drugs efficient in treating cancer and multidrug-resistant bacteria.

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Vaverkova, Veronika, Oldrich Vrana, Vojtech Adam, Tomas Pekarek, Josef Jampilek, and Petr Babula. "The Study of Naphthoquinones and Their Complexes with DNA by Using Raman Spectroscopy and Surface Enhanced Raman Spectroscopy: New Insight into Interactions of DNA with Plant Secondary Metabolites." BioMed Research International 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/461393.

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Naphthoquinones represent the group of plant secondary metabolites with cytotoxic properties based on their ability to generate reactive oxygen species and interfere with the processes of cell respiration. Due to this fact, the possible cytotoxic mechanisms on cellular and subcellular levels are investigated intensively. There are many targets of cytotoxic action on the cellular level; however, DNA is a critical target of many cytotoxic compounds. Due to the cytotoxic properties of naphthoquinones, it is necessary to study the processes of naphthoquinones, DNA interactions (1,4-naphthoquinone, binapthoquinone, juglone, lawsone, plumbagin), especially by using modern analytical techniques. In our work, the Raman spectroscopy was used to determine the possible binding sites of the naphthoquinones on the DNA and to characterize the bond of naphthoquinone to DNA. Experimental data reveals the relationships between the perturbations of structure-sensitive Raman bands and the types of the naphthoquinones involved. The modification of DNA by the studied naphthoquinones leads to the nonspecific interaction, which causes the transition of B-DNA into A-DNA conformation. The change of the B-conformation of DNA for all measured DNA modified by naphthoquinones except plumbagin is obvious.

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Ball, M. D., M. S. Bartlett, M. Shaw, J. W. Smith, M. Nasr, and S. R. Meshnick. "Activities and Conformational Fitting of 1,4-Naphthoquinone Derivatives and Other Cyclic 1,4-Diones Tested In Vitro against Pneumocystis carinii." Antimicrobial Agents and Chemotherapy 45, no. 5 (May 1, 2001): 1473–79. http://dx.doi.org/10.1128/aac.45.5.1473-1479.2001.

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ABSTRACT Atovaquone is a chemotherapeutic agent used to treat pneumonia caused by Pneumocystis carinii in some immunocompromised patients. A set of cyclic 1,4-diones were tested in vitro for ability to inhibit growth of P. carinii, including 22 variously substituted 1,4-naphthoquinones, one bis-1,4-naphthoquinone, and three other quinones. For comparison, the antipneumocystic primaquine and its 5-hydroxy-6-desmethyl metabolite were also tested. At 1.0 μg/ml, seven compounds inhibited growth by at least 39%, with atovaquone at 92%; of these seven, five are 2-hydroxy-1,4-naphthoquinones, while one is a 2-chloro- and another is a 2-methyl-1,4-naphthoquinone. At 0.1 μg/ml, however, the most active compound tested was the primaquine metabolite, which inhibited growth by more than 42% at this concentration. To ascertain a structure-activity relationship, all 1,4-naphthoquinones were compared conformationally by means of computer-based molecular modeling (Spartan) incorporating the Sybyl force field. Without exception, for all 21 monomers tested, the substituent at position 3 of the 1,4-naphthoquinone favored activity most strongly when it simultaneously occupied (i) space centered at about 3 Å from position 3, without projecting steric bulk from the area encompassed by atovaquone's cyclohexyl ring, and (ii) roughly planar space at about 7.3 Å from position 3, without projecting steric bulk perpendicularly. This structure-activity relationship may prove useful in the rational design of better antipneumocystis agents.

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Chakraborty, Soumen, Gaurav Das, Surajit Ghosh, and Dipakranjan Mal. "Regioselective synthesis of naphthoquinone/naphthoquinol–carbohydrate hybrids by [4 + 2] anionic annulations and studies on their cytotoxicity." Organic & Biomolecular Chemistry 14, no. 45 (2016): 10636–47. http://dx.doi.org/10.1039/c6ob02154a.

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Molleti, Nagaraju, and Vinod K. Singh. "Highly enantioselective synthesis of naphthoquinones and pyranonaphthoquinones catalyzed by bifunctional chiral bis-squaramides." Organic & Biomolecular Chemistry 13, no. 18 (2015): 5243–54. http://dx.doi.org/10.1039/c5ob00105f.

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A variety of enantioenriched naphthoquinones has been synthesized in high yields and excellent enantioselectivities (up to >99% ee) using a bifunctional chiral bis-squaramide catalyzed conjugate addition of 2-hydroxy-1,4-naphthoquinone to 2-enoylpyridines.

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Ribeiro, Ruan Carlos B., Patricia G. Ferreira, Amanda de A. Borges, Luana da S. M. Forezi, Fernando de Carvalho da Silva, and Vitor F. Ferreira. "1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis." Beilstein Journal of Organic Chemistry 18 (January 5, 2022): 53–69. http://dx.doi.org/10.3762/bjoc.18.5.

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Several low molecular weight naphthoquinones are very useful in organic synthesis. These compounds have given rise to thousands of other naphthoquinones that have been tested against various microorganisms and pharmacological targets, including being used in the preparation of several drugs that are on the pharmaceutical market. Among these naphthoquinones, the series of compounds prepared from 1,2-naphthoquinone-4-sulfonic acid salts (β-NQS) stands out. In addition to being used in organic synthesis, they are excellent analytical derivatization reagents to spectrophotometrically determine drugs containing primary and secondary amino groups. This review summarizes the literature involving β-NQS.

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Schlauer, Jan, Andreas Wistuba, Siegfried R. H. Hartmeyer, and Irmgard Hartmeyer. "The taxonomic relevance of Naphthoquinones in tropical pitcher plants (Nepenthes L., Nepenthaceae)." Carnivorous Plant Newsletter 51, no. 4 (December 1, 2022): 185–93. http://dx.doi.org/10.55360/cpn514.js802.

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The distribution of the naphthoquinones ramentaceone and plumbagin was studied among 50 taxa of the genus Nepenthes. Naphthoquinone patterns support classifications based on homology of plastid and/or nuclear genes to some extent, with plumbagin predominant in sections Nepenthes, Urceolatae, Tentaculatae, and Regiae, ramentaceone predominant in sections Insignes and Villosae, and both isomers present without clear predominance in sections Pyrophytae and Montanae. Only 9 of 96 studied species contained both isomers in the same plant. Naphthoquinone data from artificial hybrids of known parentage allowed conclusions on the biosynthesis of these compounds and the heredity of the respective enzymatic steps.

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Tandon, Vishnu K., Hardesh K. Maurya, Sandeep Kumar, Aijaz Rashid, and Dulal Panda. "Synthesis and evaluation of 2-heteroaryl and 2,3-diheteroaryl-1,4-naphthoquinones that potently induce apoptosis in cancer cells." RSC Adv. 4, no. 24 (2014): 12441–47. http://dx.doi.org/10.1039/c3ra47720g.

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This article describes the preparation of 2-heteroaryl and 600 dpi in TIF format)??>2,3-diheteroaryl-1,4-naphthoquinones by an environmentally benign short synthetic route with the goal of finding 1,4-naphthoquinone derivatives that induce apoptosis in cancer cells.

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Yang, Xiaojuan, and Liqiang Wu. "Synthesis of Novel 1,4-Naphthoquinones Possessing Indole Scaffolds Using In(OTf)3 in Solvent-Free Conditions." Molecules 23, no. 8 (August 6, 2018): 1954. http://dx.doi.org/10.3390/molecules23081954.

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Novel 1,4-naphthoquinones possessing indole scaffolds were prepared by the reaction of 2-hydroxy-1,4-naphthoquinone-substituted salicylic aldehydes and indoles using In(OTf)3 as a catalyst. The method has the advantages of simple operation, mild reaction conditions, and friendly environment.

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Kallmayer, H. J., and M. Doerr. "Die Reaktion des 2,3,4a,8a-Tetrachlor-6,7-dimethyl-4a,5,8,8a-tetrahydro-1,4-naphthochinons mit Aminen." Scientia Pharmaceutica 68, no. 2 (April 1, 2000): 129–39. http://dx.doi.org/10.3797/scipharm.aut-00-12.

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2,3,4a,8a-Tetrachloro-6,7-dimethyl-4a,5 ,8,8a-tetrahydro-1,4-naphthoquinone (5) reacts with arylamines 8a-e to give 2-amino-dihydroquinones 4a-e. Alkylamines 8f and h give 2-amino-dihydroquinones 4f, h and 2-amino-1,4-naphthoquinones 7f, h, dialkylamines 9f, g, i and j give 2-amino-dihydroqulnones 3f, g, i, j, 2-amino-1,4-naphthoquinones 6f, g, i, j and the photodesalkylated products 10f and g.

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Polonik, Sergey, Yuri Sabutskii, and Vladimir Denisenko. "The Acid-Catalyzed 2-O-Alkylation of Substituted 2-Hydroxy-1,4-naphthoquinones by Alcohols: Versatile Preparative Synthesis of Spinochrome D and Its 6-Alkoxy Derivatives." Synthesis 50, no. 18 (July 12, 2018): 3738–48. http://dx.doi.org/10.1055/s-0037-1610415.

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A series of substituted 2-alkoxy-1,4-naphthoquinone derivatives were obtained by acid-catalyzed condensation of substituted 2-hydroxy-1,4-naphthoquinones with propan-1-ol, butan-1-ol, or pentan-1-ol in good yields. Based on this reaction a versatile preparative synthesis of spinochrome D was developed.

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25

Medina, Luis F. C., Valter Stefani, and Adriano Brandelli. "Use of 1,4-naphthoquinones for control of Erwinia carotovora." Canadian Journal of Microbiology 50, no. 11 (November 1, 2004): 951–56. http://dx.doi.org/10.1139/w04-088.

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The antimicrobial effect of 5 naphthoquinones was tested against the phytopathogenic bacteria Erwinia carotovora. Disk diffusion tests and determination of minimal inhibitory concentrations (MIC) indicate that the compound naphthazarin (NTZ) has the best antibacterial activity among the naphthoquinones tested. Studies on the mode of action indicate the effect of NTZ was bactericidal at 10 µg/mL. When cultivation was done in the presence of sodium ascorbate, the restoration of E. carotovora growth was observed with 3 µg/mL NTZ, but not when a 10 µg/mL dose was used. The incubation of NTZ with bacterial suspension of E. carotovora resulted in important changes in the absorption spectra of this naphthoquinone, indicating that a redox reaction takes place. These results may suggest that NTZ induces an increase of reactive oxygen species that are toxic to the cell. The compound NTZ was also effective in preventing E. carotovora growth on potato tubers, inhibiting the soft rot development at a concentration of 2 mg/mL.Key words: antimicrobial, naphthazarin, phytopathogen, potato, 5,8-dihydroxy-1,4-naphthoquinone.

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26

Schlauer, Jan, and Andreas Fleischmann. "Naphthoquinones in Pygmy Sundews (Drosera sect. Bryastrum)." Carnivorous Plant Newsletter 50, no. 3 (September 1, 2021): 111–17. http://dx.doi.org/10.55360/cpn503.js430.

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A detailed study of 44 accessions representing 38 taxa (76% of the diversity known at present) of pygmy sundews (Drosera sect. Bryastrum) reveals the first naphthoquinone patterns in this lineage, in which previous studies have not yielded reliable evidence for naphthoquinones. While most samples do not display detectable amounts of naphthoquinones as previously reported for the group, ramentaceone is detected in three mutually related taxa, and both ramentaceone and its regio-isomer plumbagin is present in all accessions investigated of D. pulchella.

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27

Genovese, Salvatore, Vito Alessandro Taddeo, Francesco Epifano, and Serena Fiorito. "Complexes of Lapachol and Lawsone with Lanthanides." Natural Product Communications 10, no. 11 (November 2015): 1934578X1501001. http://dx.doi.org/10.1177/1934578x1501001105.

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Naturally occurring 2-hydroxy-1,4-naphthoquinones are well known to form readily stable complexes with transition metals. In this short communication we describe for the first time the synthesis and preliminary data about structural characterization of complexes between two naturally widespread 2-hydroxy-1,4-naphthoquinones, namely lapachol (1) and lawsone (2), with selected lanthanides like lanthanum, gadolinium, and ytterbium. When tested as cytotoxic compounds, such complexes exhibited an activity that was either higher or equal to that of the parent naphthoquinone.

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28

Migulin, Vasily A. "A New Synthetic Pathway to Symmetric Bisubstituted Naphthoquinones." Synthesis 52, no. 01 (October 23, 2019): 60–68. http://dx.doi.org/10.1055/s-0039-1690725.

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straightforward and practical synthesis of 2,3-diiodo-1,4-naphthoquinone is reported. Based on the prepared diiodide, a new synthetic approach to symmetric bisubstituted 1,4-naphthoquinones via double Suzuki–Miyaura reaction at room temperature has been researched and developed. The presented general method combines broad-spectrum applicability, efficiency, and simplicity providing target materials in good to quantitative yields.

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29

Polonik, Sergey G., Natalia V. Krylova, Galina G. Kompanets, Olga V. Iunikhina, and Yuri E. Sabutski. "Synthesis and Screening of Anti-HSV-1 Activity of Thioglucoside Derivatives of Natural Polyhydroxy-1,4-Naphthoquinones." Natural Product Communications 14, no. 6 (June 2019): 1934578X1986067. http://dx.doi.org/10.1177/1934578x19860672.

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Four 1,4-naphthoquinone dithioglucoside derivatives based on natural polyhydroxy-1,4-naphthoquinones were synthesized. These thioglucosides were screened for their antiradical and antiviral activity in vitro. Antiradical activity of tested compounds was determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. The anti-herpes simplex virus type 1 (anti-HSV-1) activity of thioglucosides was analyzed by the cytopathic effect inhibition assay and mode of antiviral action was determined by the addition of the tested compounds to uninfected cells, to the virus prior to infection, or to herpes-infected cells. Most effective inhibition of HSV-1 replication was observed at pretreatment of virus by the compounds (direct virucidal effect). The dithioglucoside conjugate with the single β-OH group and lipophilic ethyl substituent in naphthoquinone core showed the greatest antiviral activity.

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30

Butler, Mark S., Peter L. Katavic, Paul I. Forster, and Gordon P. Guymer. "Two New Naphthoquinones from the Roots of Conospermum sphacelatum." Australian Journal of Chemistry 52, no. 8 (1999): 813. http://dx.doi.org/10.1071/ch99041.

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Two new naphthoquinones, 8-[(2′E)-3′,7′-dimethylocta-2′,6′-dienyl]-2,7-dihydroxynaphthalene-1,4-dione (1) and 2-hydroxy-6,7-dimethoxy-3-methylnaphthalene-1,4-dione (2), and one known naphthoquinone, (+)-teretifolione-B (3), were isolated from the roots of Conospermum sphacelatum Hook. (Proteaceae) collected in central Queensland. The structures of compounds (1) and (2) were determined by spectroscopic analysis.

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31

Sabutski, Yuri E., Ekaterina S. Menchinskaya, Ludmila S. Shevchenko, Ekaterina A. Chingizova, Artur R. Chingizov, Roman S. Popov, Vladimir A. Denisenko, Valery V. Mikhailov, Dmitry L. Aminin, and Sergey G. Polonik. "Synthesis and Evaluation of Antimicrobial and Cytotoxic Activity of Oxathiine-Fused Quinone-Thioglucoside Conjugates of Substituted 1,4-Naphthoquinones." Molecules 25, no. 16 (August 6, 2020): 3577. http://dx.doi.org/10.3390/molecules25163577.

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A series of new tetracyclic oxathiine-fused quinone-thioglycoside conjugates based on biologically active 1,4-naphthoquinones and 1-mercapto derivatives of per-O-acetyl d-glucose, d-galactose, d-xylose, and l-arabinose have been synthesized, characterized, and evaluated for their cytotoxic and antimicrobial activities. Six tetracyclic conjugates bearing a hydroxyl group in naphthoquinone core showed high cytotoxic activity with EC50 values in the range of 0.3 to 0.9 μM for various types of cancer and normal cells and no hemolytic activity up to 25 μM. The antimicrobial activity of conjugates was screened against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus), Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), and fungus Candida albicans by the agar diffusion method. The most effective juglone conjugates with d-xylose or l-arabinose moiety and hydroxyl group at C-7 position of naphthoquinone core at concentration 10 µg/well showed antimicrobial activity comparable with antibiotics vancomicin and gentamicin against Gram-positive bacteria strains. In liquid media, juglone-arabinosidic tetracycles showed highest activity with MIC 6.25 µM. Thus, a positive effect of heterocyclization with mercaptosugars on cytotoxic and antimicrobial activity for group of 1,4-naphthoquinones was shown.

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32

Valderrama, Jaime A., Andrea Pérez-Herrera, Giulio G. Muccioli, Edmundo A. Venegas-Casanova, Rafael Jara-Aguilar, Pedro Buc Calderon, and Julio Benites. "On the Reaction of 2-Alkanoylnaphthohydroquinones with Hydroxylamine: Access to Cytotoxic 2-(Hydroxyamino)-1,4-naphthoquinone and Their 3-(Hydroxyimino)alkyl Analogous." Journal of Chemistry 2022 (August 23, 2022): 1–8. http://dx.doi.org/10.1155/2022/7664037.

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Oximes are known for their anti-inflammatory, antimicrobial, antioxidant, and anticancer activities. Frequently, modification of biologically active carbonyl compounds into oximes leads to increased activity. The present study reports the reactivity of 2-alkanoylnaphthohydroquinones against hydroxylamine under aerial conditions. Results show that, depending on the structure of the hydroquinones, the reaction proceeds through two different chemical pathways to produce 2-(hydroxyamino)-1,4-naphthoquinone and their C-3 (hydroxyimino)alkyl derivatives. Both the formation of the quinoid compounds under aerial oxidation and C-C cleavage reactions of hemiaminal intermediates are discussed. In vitro screening of the substituted 1,4-naphthoquinones on a panel of cancer cells reveals moderate cytotoxic activities. Compound 19, 2-(hydroxyamino)-1,4-naphthoquinone, stands out by its anticancer potency against prostate cancer cells as shown by the lowest IC50 value (8.08 μM) and the best selectivity index (3.90).

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33

Cameron, Donald W., and Andrew G. Riches. "Reaction of 2-Acetoxy-3-chloro and 2,3-Diacetoxy Naphthoquinones with 1,3-Dioxy and 1,1,3-Trioxy Butadienes." Australian Journal of Chemistry 52, no. 12 (1999): 1165. http://dx.doi.org/10.1071/ch99179.

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Reaction of 2-acetoxy-3-chloro naphthoquinones towards the 1,3-dioxy diene (2) and the 1,1,3-trioxy diene (9) was examined. The competing influence of the acetoxy and chloro substituents was assessed from the regiochemistry of the resulting Diels–Alder chemistry, as was competition between that process and Michael addition/elimination. Reaction of the same dienes towards the less reactive 2,3-diacetoxy naphthoquinone (25) was also investigated.

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34

Topçu, Seray, and Mine Gül Şeker. "In Vitro Antimicrobial Effects and Inactivation Mechanisms of 5,8-Dihydroxy-1,4-Napthoquinone." Antibiotics 11, no. 11 (November 3, 2022): 1537. http://dx.doi.org/10.3390/antibiotics11111537.

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Naphthoquinones are an important class of natural organic compounds that have antimicrobial effects. However, the mechanisms of their action remain to be elucidated. Therefore, the antimicrobial activity of the chemically synthesized naphthoquinone derivative, 5,8-dihydroxy-1,4-naphthoquinone, was investigated in this study against 10 different microorganisms. Its inhibitory activity was evident against Bacillus cereus, Proteus vulgaris, Salmonella enteritidis, Staphylococcus epidermidis, S. aureus, and Candida albicans, and its MIC50 values were determined to be 14, 10, 6, 2, 4, 1.2, and <0.6 µg/mL, respectively. Moreover, the crystal violet uptake, TTC dehydrogenase activity, protein/DNA leakage, and DNA damage of the compound in these microorganisms were also investigated to reveal the antimicrobial mechanisms. In addition, scanning electron microscopy was used to detect physiological damage to the cell membrane of S. epidermidis, S. aureus, and C. albicans, which was most severe in the crystal violet uptake assay. The overall results showed that 5,8-dihydroxy-1,4-naphthoquinone exhibited its effects on S. aureus, S. epidermidis, and C. albicans by various mechanisms, especially membrane damage and membrane integrity disruption. It also caused DNA leakage and damage along with respiratory chain disruption (78%) in C. albicans. Similarly, it caused varying degrees of reduction in the respiratory activity of S. aureus (47%), S. epidermidis (16%), B. cereus (12%), S. enteritidis (9%), and P. vulgaris (8%). Therefore, 5,8-dihydroxy-1,4-naphthoquinone proved to be a very effective antifungal and antibacterial agent and could be considered a new potential drug candidate, inspiring further discoveries in these microorganisms.

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35

Jeziorek, Małgorzata, Katarzyna Sykłowska-Baranek, and Agnieszka Pietrosiuk. "Hairy Root Cultures for the Production of Anti-cancer Naphthoquinone Compounds." Current Medicinal Chemistry 25, no. 36 (December 3, 2018): 4718–39. http://dx.doi.org/10.2174/0929867324666170821161844.

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Background: Recent years have brought the dynamic development in studies of naphthoquinones obtained from plants, in vitro cultures and semi- or total synthesis. This review presents the hairy root cultures approach for producing naphthoquinones and summarizes their most recent anti-cancer investigations. <p> Objective: This review aimed to define biotechnological strategies impacted on naphthoquinones production in hairy root cultures. Up to now the major source of shikonin/alkannin derivatives, rhinacanthins and ramentaceone is isolation from plant material, also derived via biotechnological methods. Moreover, the most recent anti-cancer activity studies on naphthoquinones which could be produced in hairy root cultures were outlined. <p> Methods: For databases survey two selection criteria were used: (i) naphthoquinone could be produced in hairy roots, and (ii) it exhibits anti-cancer properties. <p> Results: Ninety two papers were included in the review, thirty described biotechnological approaches enhancing naphthoquinones production, among them twenty seven were dedicated to hairy root cultures. Forty papers outlined the anti-cancer activity of targeted naphthoquinones including the type of cancer and bioassays description. The synergistic effect of natural naphthoquinones and other anti-cancer therapies was reviewed and toxicity of natural naphthoquinones and plant extracts was discussed. The review highlights tendencies in hairy root investigations and indicates the possible future research directions for improving biotechnological production efficacy. <p> Conclusion: This review demonstrates a great potential of hairy root cultures for naphthoquinones production, which could be furtherly developed for future medical purposes, especially as anti-cancer agents. This area of plant biotechnology will be surely still developed with traditional and new strategies.

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36

Ribeiro, Marcos, Humberto Stumpf, and Carlos Pinheiro. "Investigating valence tautomerism presence in compounds of Co and naphthoquinone." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1257. http://dx.doi.org/10.1107/s2053273314087427.

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The search for new functional materials involves the development of bistable molecules exhibiting different electronic states with distinct properties at the ambient condition (temperature, pressure, illumination) of application. Coordination compounds, which present electron transfer between metal ion and an organic ligand associated with a change in electron multiplicity of the metal ion, are named valence tautomers(VT)[1]. The chemical equilibrium between two distinct electronic states in VT can be induced by temperature and pressure change as well as by soft X-ray and light irradiation. Thermodynamic and structural data highlighting the mechanisms of the valence tautomerism interconversion can be found in the literature for materials build up with cobalt and benzoquinones such as the 3,5-di-t-butyl-semiquinonate. However, to the best of our knowledge, there is no example of compounds showing VT build up with cobalt and naphthoquinones. In the present work 2-hydroxy-1,4-naphthoquinone (law) has been used as redox active ligands in the search for new VT compounds with cobalt. Three new coordination compounds of cobalt and 2-hydroxy-1,4-naphthoquinone (law), [Co(law)2(im)2], [Co(law)2(phen)] e [Co(law)2(bpy)] were synthesized and characterized by infrared (IR), UV-vis spectroscopy, electron paramagnetic resonance (EPR) and cyclic voltammetry. The three dimensional structures were determined using single crystal X-ray diffraction techniques. However, within the investigated temperature range neither X-ray diffraction nor EPR data showed the presence of VT in the materials, mainly due to the electrochemical properties of the 2-hydroxy-1,4-naphthoquinone. Nevertheless the structural features of the compounds as well as their supramolecular packing motifs suggest that naphthoquinones can be an alternative for the synthesis of compounds showing valence tautomerism[3].

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37

Kažemekaite, Maryte, Vilma Railaite, Arunas Bulovas, Zita Talaikyte, Gediminas Niaura, Valdemaras Razumas, and Eugenijus Butkus. "Synthesis, Self-Assembling and Redox Properties of 2-[(ω-Sulfanylalkyl)amino]-1,4-naphthoquinones." Collection of Czechoslovak Chemical Communications 71, no. 9 (2006): 1383–91. http://dx.doi.org/10.1135/cccc20061383.

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The newly synthesized 1,4-naphthoquinones linked via nitrogen atom to a short chain with terminal sulfanyl group form self-assembled monolayers on gold. The main electrochemical parameters of the monolayers were determined by cyclic voltammetry. Combined voltammetric and in situ Fourier-transform surface-enhanced Raman spectroscopic studies of the Au electrode modified with the title compounds clearly evidence that naphthoquinone group transforms into naphthalenediol during a reduction process.

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38

Owen, Josee, and K. A. Stewart. "The Effects of Nitrogen on the Growth, Development, and Medicinal Compound Yield of the Sundew Drosera adelae." HortScience 32, no. 3 (June 1997): 523E—523. http://dx.doi.org/10.21273/hortsci.32.3.523e.

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Drosera spp. are used in alternative medicine as sources of the beneficial naphthoquinone compounds plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) and 7-methyljuglone. Presently, Drosera are harvested from the wild with great detriment to bog habitats. This study focused on the development of a hydroponic rockwool culture of the sundew D. adelae. Tissue-cultured plantlets were raised as transplants in peatmoss. The transplants were planted directly into rockwool slabs primed to pH 6. Three levels of ammonium nitrate fertilizer were applied, the highest level of which approximated natural peat bog levels. Growth and development of the plants was monitored. Plants from each nitrogen treatment were harvested and subjected to extraction with toluene. Subsequently, high-performance gas chromatography was used to separate and quantify the naphthoquinones present in the extract. This method was used for three harvests: harvest of transplants, harvest after 2 months, and after 4 months of active growth.

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39

Ourhzif, El-Mahdi, Caroline Decombat, Isabelle Abrunhosa-Thomas, Laetitia Delort, Mostafa Khouili, Mohamed Akssira, Florence Caldefie-Chezet, Pierre Chalard, and Yves Troin. "Synthesis and Biological Evaluation of New Naphthoquinones Derivatives." Current Organic Synthesis 17, no. 3 (June 9, 2020): 224–29. http://dx.doi.org/10.2174/1570179417666200212111956.

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: New substituted 1,4-naphthoquinones have been prepared in good overall yields through the naphthol route. The cytotoxicity of these compounds was tested in vitro on MCF-7 breast tumor cells. The most active compound 14 displayed an IC50 of 15μM. Objective: To investigate the cytotoxicity of new naphthoquinones derivatives on MCF-7 cells. Methods: Synthesis of new naphtoquinones derivatives and in vitro evaluation of their cytotoxicity on MCF-7 cells (rezasurin cell-based assay). Results: Starting from Ethyl 4-hydroxy-6,7-dimethoxy-2-naphthoate, four naphthoquinones were prepared and exhibited substantial cytotoxicity against MCF-7 cells. Conclusion: Preliminary studies of the structure-activity relationship have shown the influence of the structural parameters and, in particular, the nature of the naphthoquinone side chain.

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40

Hammam, A. S., and B. E. Bayoumy. "Reaction of thioamides with 2,3-dichloro-1,4-naphthoquinone. A novel synthesis of naphtho[2,3-d]thiazole-4,9-diones." Collection of Czechoslovak Chemical Communications 50, no. 1 (1985): 71–79. http://dx.doi.org/10.1135/cccc19850071.

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The reaction of thioamide II with 2,3-dichloro-1,4-naphthoquinone (I) in ethanol gave naptho[2,3-d]thiazole-4,9-diones (IV). The intermediates, 2-thioamido-3-chloro-1,4-naphthoquinones III were also isolated from the reaction medium and could be separately transformed to IV by further boiling in aqueous ethanol containing bicarbonate. The reaction of thiosemicarbazide with I under similar conditions gave naphtho[2,3-e]-2-amino-4H-1,3,4-thiadiazine-5,10-dione (VII).

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41

Ravichandiran, Palanisamy, Sunirmal Sheet, Dhanraj Premnath, Ae Rhan Kim, and Dong Jin Yoo. "1,4-Naphthoquinone Analogues: Potent Antibacterial Agents and Mode of Action Evaluation." Molecules 24, no. 7 (April 11, 2019): 1437. http://dx.doi.org/10.3390/molecules24071437.

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1,4-Naphthoquinones have antibacterial activity and are a promising new class of compound that can be used to treat bacterial infections. The goal was to improve effective antibacterial agents; therefore, we synthesized a new class of naphthoquinone hybrids, which contain phenylamino-phenylthio moieties as significant counterparts. Compound 4 was modified as a substituted aryl amide moiety, which enhanced the antibacterial activity of earlier compounds 3 and 4. In this study, five bacterial strains Staphylococcus aureus (S. aureus), Listeria monocytogenes (L. monocytogenes), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae) were used to evaluate the antibacterial potency of synthesized naphthoquinones using the minimal inhibitory concentration (MIC) method. Most of the studied naphthoquinones demonstrated major antibacterial activity with a MIC of 15.6 µg/mL–500 µg/mL. Selected compounds (5a, 5f and 5x) were studied for the mode of action, using intracellular ROS generation, determination of apoptosis by the Annexin V-FITC/PI assay, a bactericidal kinetic study and in silico molecular modelling. Additionally, the redox potentials of the specified compounds were confirmed by cyclic voltammetry (CV).

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Khan, Muhammad, Muhammad Ajmal Shah, Mustafa Kamal, Mohammad Shamsul Ola, Mehboob Ali, and Pharkphoom Panichayupakaranant. "Comparative Antihyperglycemic and Antihyperlipidemic Effects of Lawsone Methyl Ether and Lawsone in Nicotinamide-Streptozotocin-Induced Diabetic Rats." Metabolites 13, no. 7 (July 20, 2023): 863. http://dx.doi.org/10.3390/metabo13070863.

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Our previous study uncovered potent inhibitory effects of two naphthoquinones from Impatiens balsamina, namely lawsone methyl ether (2-methoxy-1,4-naphthoquinone, LME) and lawsone (2-hydroxy-1,4-naphthoquinone), against α-glucosidase. This gave us the insight to compare the hypoglycemic and hypolipidemic effects of LME and lawsone in high-fat/high-fructose-diet- and nicotinamide-streptozotocin-induced diabetic rats for 28 days. LME and lawsone at the doses of 15, 30, and 45 mg/kg, respectively, produced a substantial and dose-dependent reduction in the levels of fasting blood glucose (FBG), HbA1c, and food/water intake while boosting the insulin levels and body weights of diabetic rats. Additionally, the levels of total cholesterol (TC), triglycerides (TGs), high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), aspartate transaminase (AST), alanine transaminase (ALT), creatinine, and blood urea nitrogen (BUN) in diabetic rats were significantly normalized by LME and lawsone, without affecting the normal rats. LME at a dose of 45 mg/kg exhibited the most potent antihyperglycemic and antihyperlipidemic effects, which were significantly comparable to glibenclamide but higher than those of lawsone. Furthermore, the toxicity evaluation indicated that both naphthoquinones were entirely safe for use in rodent models at doses ≤ 50 mg/kg. Therefore, the remarkable antihyperglycemic and antihyperlipidemic potentials of LME make it a promising option for future drug development.

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Sunday Etukudoh, Nkereuwem, Opeyemi Oreofe Akindele, Olufadekemi Tolulope Kunle-Alabi, and Adeyombo Folashade Bolarinwa. "Naphthoquinone impairs reproductive functions in plasmodium berghei berghei-infected male swiss mice." International Journal of Basic and Applied Sciences 8, no. 1 (May 5, 2019): 1. http://dx.doi.org/10.14419/ijbas.v8i1.10355.

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Background: Various antimalarial drugs adversely affect male reproductive functions. Naphtoquinones, a class of antimalarial drugs have been shown to effectively combat malaria parasites. However, the effects of naphtoquinone on reproductive functions remain elusive. The study determined the effects of naphthoquinone on reproductive functions of Plasmodium berghei berghei-infected male Swiss miceMethods: Thirty male Swiss mice were divided into 6 groups (n = 5) namely; Control, 1 mg/kg naphthoquinone, 2 mg/kg naphthoquinone, Plasmodium berghei berghei (Pbb)-infected, Pbb-infected+1 mg/kg naphthoquinone and Pbb-infected+2 mg/kg naphthoquinone. Parasitaemia was confirmed by microscopy. Naphthoquinone (i.p.) was administered for seven days following confirmation of parasitaemia. Thereafter, they were sacrificed. Serum levels of FSH, LH, testosterone and cortisol were assayed via ELISA. Sperm characteristics were evaluated by microscopy. Data were expressed as mean ± SEM and analysed using ANOVA at p<0.05.Results: Sperm motility reduced in the Pbb-infected compared with control. Sperm viability, motility and count reduced in naphthoquinone only groups and Pbb-infected+naphthoquinone groups compared with the control. Naphthoquinone groups and Pbb-infected alone decreased in LH and testosterone concentrations compared with the control.Conclusion: Naphthoquinone treatment impaired reproductive functions in Plasmodium berghei berghei-infected male Swiss mice.

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Prieto Cárdenas, Lina S., Karen A. Arias Soler, Diana L. Nossa González, Wilson E. Rozo Núñez, Agobardo Cárdenas-Chaparro, Pablo R. Duchowicz, and Jovanny A. Gómez Castaño. "In Silico Antiprotozoal Evaluation of 1,4-Naphthoquinone Derivatives against Chagas and Leishmaniasis Diseases Using QSAR, Molecular Docking, and ADME Approaches." Pharmaceuticals 15, no. 6 (May 31, 2022): 687. http://dx.doi.org/10.3390/ph15060687.

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Chagas and leishmaniasis are two neglected diseases considered as public health problems worldwide, for which there is no effective, low-cost, and low-toxicity treatment for the host. Naphthoquinones are ligands with redox properties involved in oxidative biological processes with a wide variety of activities, including antiparasitic. In this work, in silico methods of quantitative structure–activity relationship (QSAR), molecular docking, and calculation of ADME (absorption, distribution, metabolism, and excretion) properties were used to evaluate naphthoquinone derivatives with unknown antiprotozoal activity. QSAR models were developed for predicting antiparasitic activity against Trypanosoma cruzi, Leishmania amazonensis, and Leishmania infatum, as well as the QSAR model for toxicity activity. Most of the evaluated ligands presented high antiparasitic activity. According to the docking results, the family of triazole derivatives presented the best affinity with the different macromolecular targets. The ADME results showed that most of the evaluated compounds present adequate conditions to be administered orally. Naphthoquinone derivatives show good biological activity results, depending on the substituents attached to the quinone ring, and perhaps the potential to be converted into drugs or starting molecules.

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Paiva, Selma R. de, Lucilene A. Lima, Maria Raquel Figueiredo, and Maria Auxiliadora C. Kaplan. "Plumbagin quantification in roots of Plumbago scandens L. obtained by different extraction techniques." Anais da Academia Brasileira de Ciências 76, no. 3 (September 2004): 499–504. http://dx.doi.org/10.1590/s0001-37652004000300004.

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The Plumbago genus belongs to the Plumbaginaceae family and it is known due to its variety of biological uses, most of them attributed to the presence of naphthoquinones. Plumbagin is a naturally occurring naphthoquinone that can be obtained from roots of Plumbago scandens L. In order to find out the better technique for plumbagin extraction, were applied: static maceration, dynamic maceration, with assistance of ultrasonic waves and in Soxhlet apparatus. Four compounds were qualitatively detected in all extracts: the naphthoquinones plumbagin and epi-isoshinanolone, palmitic acid and sitosterol. Plumbagin was always the major component in all analyzed extracts and it was quantitatively determined by gas chromatograph coupled with mass spectrometer. Soxhlet was the most efficient extraction technique however, prolonged heating time promoted plumbagin degradation.

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Paiva, Selma R., Lucilene A. Lima, Maria Raquel Figueiredo, and Maria Auxiliadora C. Kaplan. "Chemical composition fluctuations in roots of Plumbago scandens L. in relation to floral development." Anais da Academia Brasileira de Ciências 83, no. 4 (December 2011): 1165–70. http://dx.doi.org/10.1590/s0001-37652011000400004.

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Plumbago scandens L. is a Brazilian tropical/subtropical species that occurs along the coast. Chemically it is mainly represented by naphthoquinones, flavonoids, terpenoids and steroids. The aim of the present work is to study quantitative changes in the root metabolic production of Plumbago scandens during different physiologic developmental stages relative to floration. The results indicated the presence of four substances in the extracts: plumbagin, epi-isoshinanolone, palmitic acid and sitosterol, independent on developmental stage. The naphthoquinone plumbagin has always showed to be the major component of all extracts. Naphthoquinones exhibited their highest content during floration, while the content of the two others components decreased during this stage, revealing an inverse profile. The chemical composition changed depending on the plant requirements.

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Crosby, Ian T., Mark L. Rose, Maree P. Collis, Paula J. de Bruyn, Philip L. C. Keep, and Alan D. Robertson. "Antiviral Agents. I. Synthesis and Antiviral Evaluation of Trimeric Naphthoquinone Analogues of Conocurvone." Australian Journal of Chemistry 61, no. 10 (2008): 768. http://dx.doi.org/10.1071/ch08177.

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Conocurvone, a novel natural product isolated from the endemic Australian shrub Conosperum sp. (Proteaceae), exhibits anti-HIV activity but is a highly lipophilic compound, which suggests that there may be problems with its aqueous solubility and bioavailability. A general and convenient synthesis of trimeric naphthoquinones using the condensation of 2-hydroxynaphthoquinones and 2,3-dihaloquinones is described. The application of this method to the synthesis of a series of simpler and less lipophilic trimeric naphthoquinone simple analogues of conocurvone is also reported together with their anti-HIV activity.

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48

Gornostaev, Leonid M. "Synthesis of 5-hydroxy-10-R-benzo[a]phenazine-12-oxides by cyclization of 2-arylamino-1,4-naphthoquinone-1-oximes under the action of nitrating mixture." Butlerov Communications 61, no. 2 (February 29, 2020): 12–23. http://dx.doi.org/10.37952/roi-jbc-01/20-61-2-12.

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The synthesis of рolycyclic quinoid compounds, which exhibit a wide range of biological activity is one of the most promising and actively developing areas of the fine organic synthesis. Heterocyclic compounds including those that can be donors of nitrogen oxide NO occupy a special place among biologically active structures. These substances include a number of N-oxides, e.g., 1,2-diazet-1,2-dioxides, furoxanes and their benzo analogs, and N,N′-pyrazole dioxides. The reason for the high biological activity of N-oxides of nitrogenous heterocycles, which cannot easily generate nitrogen oxide NO may be their oxidative properties. Thus, N-oxides of nitrogenous heterocycles are of interest due to their high biological activity. We have developed an approach to the synthesis of 5-hydroxy-10-R-benzo[a]phenazine-12-oxides that contain the N-oxide fragment, which makes these compounds promising for studying their biological activity. We have demonstrated that the treatment of 2-arylamino-1,4-naphthoquinones with hydroxylamine in ethanol at 50-60 °С leads to selective oximation at position 1 and the formation of 2-arylamino-1,4-naphthoquinone-1-oximes. It has been shown that the interaction of 2-arylamino-1,4-naphthoquinone-1-oximes with the nitrating mixture in acetic acid results in the formation of 5-hydroxy-10-R-benzo[a]phenazine-12-oxides. Our work is a continuation of the study on the interactions of 2-arylamino-1,4-naphthoquinones and 4-arylamino-1,2-naphthoquinones with nitrosylsulfuric acid in acetic acid and the interaction of 2-alkyl(benzyl)amino-1,4-naphthoquinones with nitrosylsulfuric acid or nitrating mixture in acetic acid. The former reactions lead to the formation of 3-R-benzo[b]phenazine-6,11-dione-5-oxides and 9-R-benzo[a]phenazine-5,6-dion-7-oxides, respectively. The latter reaction leads to the formation of 2-alkyl(aryl)naphtho[2,1-d][1,3]oxazole-4,5-dione-4-oximes and 2-alkyl(aryl)-1-hydroxy-1H-naphtho[2,3-d]imidazole-4,9-dione as main products.

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Kamalifar, Saiedeh, and Hamzeh Kiyani. "An Expeditious One-Pot Three-Component Synthesis of 4-Aryl-3,4-dihydrobenzo[g] quinoline-2,5,10(1H)-triones under Green Conditions." Current Organic Chemistry 23, no. 23 (January 9, 2020): 2626–34. http://dx.doi.org/10.2174/1385272823666191108123330.

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: An efficient and facial one-pot synthesis of 4-aryl-3,4-dihydrobenzo[g]quinoline- 2,5,10(1H)-triones was developed for the first time. The process proceeded via the three-component cyclocondensation of 2-amino-1,4-naphthoquinone with Meldrum’s acid and substituted benzaldehydes under green conditions. The fused 3,4-dihydropyridin-2(1H)- one-ring naphthoquinones have been synthesized with good to high yields in refluxing ethanol as a green reaction medium. This protocol is simple and effective as well as does not involve the assistance of the catalyst, additive, or hazardous solvents.

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Micheletti, Gabriele, Carla Boga, Chiara Zalambani, Giovanna Farruggia, Erika Esposito, Jessica Fiori, Nicola Rizzardi, Paola Taddei, Michele Di Foggia, and Natalia Calonghi. "Synthesis of thia-Michael-Type Adducts between Naphthoquinones and N-Acetyl-L-Cysteine and Their Biological Activity." Molecules 27, no. 17 (September 1, 2022): 5645. http://dx.doi.org/10.3390/molecules27175645.

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A series of naphthoquinones, namely, 1,4-naphthoquinone, menadione, plumbagin, juglone, naphthazarin, and lawsone, were reacted with N-acetyl-L-cysteine, and except for lawsone, which did not react, the related adducts were obtained. After the tuning of the solvent and reaction conditions, the reaction products were isolated as almost pure from the complex reaction mixture via simple filtration and were fully characterized. Therefore, the aim of this work was to evaluate whether the antitumor activity of new compounds of 1,4-naphthoquinone derivatives leads to an increase in ROS in tumor cell lines of cervical carcinoma (HeLa), neuroblastoma (SH-SY5Y), and osteosarcoma (SaOS2, U2OS) and in normal dermal fibroblast (HDFa). The MTT assay was used to assay cell viability, the DCF-DA fluorescent probe to evaluate ROS induction, and cell-cycle analysis to measure the antiproliferative effect. Compounds 8, 9, and 12 showed a certain degree of cytotoxicity towards all the malignant cell lines tested, while compound 11 showed biological activity at higher IC50 values. Compounds 8 and 11 induced increases in ROS generation after 1 h of exposure, while after 48 h of treatment, only 8 induced an increase in ROS formation in HeLa cells. Cell-cycle analysis showed that compound 8 caused an increase in the number of G0/G1-phase cells in the HeLa experiment, while for the U2OS and SH-SY5Y cell lines, it led to an accumulation of S-phase cells. Therefore, these novel 1,4-naphthoquinone derivatives may be useful as antitumoral agents in the treatment of different cancers.

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Journal articles on the topic 'Naphthoquinone'

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