Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of substituted 3-chloro-5,8-dimethoxy-1,4-naphthoquinone and related compounds

Regulation of mitochondrial function by hydroquinone derivatives as prevention of platelet activation

Platelet activation plays an essential role in the pathogenesis of thrombotic events in different diseases (e.g., cancer, type 2 diabetes, Alzheimer's, and cardiovascular diseases, and even in patients diagnosed with coronavirus disease 2019). Therefore, antiplatelet therapy is essential to reduce thrombus formation. However, the utility of current antiplatelet drugs is limited. Therefore, identifying novel antiplatelet compounds is very important in developing new drugs. In this context, the involvement of mitochondrial function as an efficient energy source required for platelet activation is currently accepted; however, its contribution as an antiplatelet target still has little been exploited. Regarding this, the intramolecular hydrogen bonding of hydroquinone derivatives has been described as a structural motif that allows the reach of small molecules at mitochondria, which can exert antiplatelet activity, among others. In this review, we describe the role of mitochondrial function in platelet activation and how hydroquinone derivatives exert antiplatelet activity through mitochondrial regulation.

An overview on the antibacterial properties of juglone, naphthazarin, plumbagin and lawsone derivatives and their metal complexes

Bacterial resistance development represents a serious threat to human health across the globe and has become a very serious clinical problem for many classes of antibiotics. Hence, there is a constant and urgent need for the discovery and development of new effective antibacterial agents to stem the emergence of resistant bacteria. 1,4-naphthoquinones are an important class of natural products and have been known for decades as a privileged scaffold in medicinal chemistry regarding their many biological properties. The significant biological properties of specific 1,4-naphthoquinones hydroxyderivatives have drawn the attention of researchers in order to find new derivatives with an optimized activity, mainly as antibacterial agents. Based on juglone, naphthazarin, plumbagin and lawsone moieties, structural optimization was realized with the purpose of improving the antibacterial activity. Thereupon, relevant antibacterial activities have been observed on different panels of bacterial strains including resistant ones. In this review, we highlight the interest of developing new 1,4-naphthoquinones hydroxyderivatives and some metal complexes as promising antibacterial agents alternatives. Here, we thoroughly report for the first time both the antibacterial activity and the chemical synthesis of four different 1,4-naphthoquinones (juglone, naphthazarin, plumbagin and lawsone) from 2002 to 2022 with an emphasis on the structure-activity relationship, when applicable.

Synthesis of thia-Michael-Type Adducts between Naphthoquinones and N-Acetyl-L-Cysteine and Their Biological Activity

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.

Computational Screening of Natural Compounds for Identification of Potential Anti-Cancer Agents Targeting MCM7 Protein

Minichromosome maintenance complex component 7 (MCM7) is involved in replicative licensing and the synthesis of DNA, and its overexpression is a fascinating biomarker for various cancer types. There is currently no effective agent that can prevent the development of cancer caused by the MCM7 protein. However, on the molecular level, inhibiting MCM7 lowers cancer-related cellular growth. With this purpose, this study screened 452 biogenic compounds extracted from the UEFS Natural Products dataset against MCM protein by using the in silico art of technique. The hit compounds UEFS99, UEFS137, and UEFS428 showed good binding with the MCM7 protein with binding energy values of −9.95, −8.92, and −8.71 kcal/mol, which was comparatively higher than that of the control compound ciprofloxacin (−6.50). The hit (UEFS99) with the minimum binding energy was picked for molecular dynamics (MD) simulation investigation, and it demonstrated stability at 30 ns. Computational prediction of physicochemical property evaluation revealed that these hits are non-toxic and have good drug-likeness features. It is suggested that hit compounds UEFS99, UEFS137, and UEFS428 pave the way for further bench work validation in novel inhibitor development against MCM7 to fight the cancers.

Ru(II)-Naphthoquinone complexes with high selectivity for triple-negative breast cancer

Six new ruthenium(ii) complexes with lapachol (Lap) and lawsone (Law) with the general formula [Ru(L)(P-P)(bipy)]PF6, where L = Lap or Law, P-P = 1,2'-bis(diphenylphosphino)ethane (dppe), 1,4'-bis(diphenylphosphino)butane (dppb), 1,1'-bis(diphenylphosphino)ferrocene (dppf) and bipy = 2,2'-bipyridine, were synthesized, fully characterized by elemental analysis, molar conductivity, NMR, cyclic voltammetry, UV-vis, IR spectroscopies and three of them by X-ray crystallography. All six complexes were active against breast (MCF-7 and MDA-MB-231) and prostate (DU-145) cancer cell lines with lower IC50 values than cisplatin. Complex [Ru(Lap)(dppe)(bipy)]PF6 (1a) showed significant selectivity for MDA-MB-231, a model of triple-negative breast cancer (TNBC), as compared to the "normal-like" human breast epithelial cell line, MCF-10A. Complex (1a) inhibited TNBC colony formation and induced loss of cellular adhesion. Furthermore, the complex (1a) induced mitochondrial dysfunction and generation of ROS, as is involved in the apoptotic cell death pathway. Preferential cellular uptake of complex (1a) was observed in MDA-MB-231 cells compared to MCF-10A cells, consistent with the observed selectivity for tumorigenic vs. non-tumorigenic cells. Taken together, these results indicate that ruthenium complexes containing lapachol and lawsone as ligands are promising candidates as chemotherapeutic agents.

A highly efficient and green protocol for the synthesis of 3,3′-(arylmethylene)-bis(2-hydroxynaphthoquinone) derivatives catalyzed by a dicationic molten salt

A highly efficient and green protocol for the synthesis of 3,3′-(arylmethylene)-bis(2-hydroxynaphthoquinone) {3,3′-(arylmethylene)-bis(2-hydroxynaphthalene-1,4-dione)} derivatives has been developed. The reaction of 2-hydroxynaphthoquinone (2-hydroxynaphthalene-1,4-dione) (2 eq.) and arylaldehydes (1 eq.) in the presence of the dicationic molten salt N,N,N′,N′-tetramethylethylenediaminium bis-hydrogensulfate ([TMEDAH2][HSO4]2) under solvent-free conditions afforded the mentioned compounds in high yields and relatively short reaction times.

Synthesis and pharmacological evaluation of acylhydroquinone derivatives as potent antiplatelet agents

Platelets are the smallest blood cells, and their activation (platelet cohesion or aggregation) at sites of vascular injury is essential for thrombus formation. Since the use of antiplatelet therapy is an unsolved problem, there are now focused and innovative efforts to develop novel antiplatelet compounds. In this context, we assessed the antiplatelet effect of an acylhydroquinone series, synthesized by Fries rearrangement under microwave irradiation, evaluating the effect of diverse acyl chain lengths, their chlorinated derivatives, and their dimethylated derivatives both in the aromatic ring and also the effect of the introduction of a bromine atom at the terminus of the acyl chain. Findings from a primary screening of cytotoxic activity on platelets by lactate dehydrogenase assay identified 19 non-toxic compounds from the 27 acylhydroquinones evaluated. A large number of them showed IC₅₀ values less than 10 µM acting against specific pathways of platelet aggregation. The highest activity was obtained with compound 38, it exhibited sub-micromolar IC₅₀ of 0.98 ± 0.40, 1.10 ± 0.26, 3.98 ± 0.46, 6.79 ± 3.02 and 42.01 ± 3.48 µM against convulxin-, collagen-, TRAP-6-, PMA- and arachidonic acid-induced platelet aggregation, respectively. It also inhibited P-selectin and granulophysin expression. We demonstrated that the antiplatelet mechanism of compound 38 was through a decrease in a central target in human platelet activation as in mitochondrial function, and this could modulate a lower response of platelets to activating agonists. The results of this study show that the chemical space around ortho-carbonyl hydroquinone moiety is a rich source of biologically active compounds, signaling that the acylhydroquinone scaffold has a promising role in antiplatelet drug research.

Lapachol in the Design of a New Ruthenium(II)-Diphosphine Complex as a Promising Anticancer Metallodrug

The preparation of two new Ru(II)/diphosphine complexes containing Lapachol (Lap) and Lawsone (Law): (1) [Ru(Lap)(dppm)₂]PF₆ and (2) [Ru(Law)(dppm)₂]PF₆, where dppm = bis(diphenylphosphino)methane, is reported here. The complexes were synthetized and fully characterized by elemental analyses, molar conductivity, UV-Vis, IR, ³¹P{¹H}, ¹H and ¹³C NMR, and the crystal structure of the complex (1) was determined by X-ray diffraction. Complexes (1) and (2) showed high in vitro cytotoxicity against four cancer cells (MDA-MB-231, MCF-7, A549 and DU-145), with IC₅₀ values in the micromolar range (0.03 to 2.70 μM). Importantly, complexes (1) and (2) were more active than the cisplatin, the drug used as a reference in the cytotoxic assays. Moreover, complex (1) showed high selectivity to triple-negative breast cancer cells (MDA-MB-231). Studies of the mechanism of action in MDA-MB-231 cancer cells showed that complex (1) inhibits cell migration, colony formation, and induces cell cycle arrest and apoptosis by activation of the mitochondrial pathway through the loss of mitochondrial membrane potential (ΔΨm). Furthermore, complex (1) induces ROS (Reactive Oxygen Species) generation in MDA-MB-231 cells, which can cause DNA damage. Finally, complexes (1) and (2) interact with DNA by minor grooves and show a moderate interaction with BSA (Bovine Serum Albumin), with the involvement of hydrophobic interactions. Essentially, Ru(II)/diphosphine-naphthoquinone complexes have remarkable cytotoxic effects with high selectivity to triple-negative breast cancer (MDA-MB-231) and could be promising anticancer candidates for cancer treatment. SYNOPSIS: The naphthoquinones Lapachol and Lawsone can form new ruthenium compounds with promising anticancer properties.

The diverse mechanisms and anticancer potential of naphthoquinones

Cancer is one of the leading causes of death around the world and although the different clinical approaches have helped to increase survival rates, incidence is still high and so its mortality. Chemotherapy is the only approach which is systemic, reaching cancer cells in all body tissues and the search for new potent and selective drugs is still an attractive field within cancer research. Naphthoquinones, natural and synthetic, have garnered much attention in the scientific community due to their pharmacological properties, among them anticancer action, and potential therapeutic significance. Many mechanisms of action have been reported which also depend on structural differences among them. Here, we describe some of the most relevant mechanisms of action reported so far for naphthoquinones and highlight novel targets which are being described in the literature. Furthermore, we gather some of the most impressive efforts done by researchers to harness the anticancer properties of these compounds through specifically designed structural modifications.

Ionically Crosslinked Chitosan Membranes Used as Drug Carriers for Cancer Therapy Application

The aim of this paper was to prepare, by the freeze-drying method, ionically crosslinked chitosan membranes with different contents of pentasodium tripolyphosphate (TPP) and loaded with 1,4-naphthoquinone (NQ14) drug, in order to evaluate how the physical crosslinking affects NQ14 release from chitosan membranes for cancer therapy application. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), swelling degree, and through in vitro drug release and cytotoxicity studies. According to the results, the molecular structure, porosity and hydrophilicity of the chitosan membranes were affected by TPP concentration and, consequently, the NQ14 drug release behavior from the membranes was also affected. The release of NQ14 from crosslinked chitosan membranes decreased when the cross-linker TPP quantity increased. Thus, depending on the TPP amount, the crosslinked chitosan membranes would be a potential delivery system to control the release of NQ14 for cancer therapy application. Lastly, the inhibitory potential of chitosan membranes ionically crosslinked with TPP and loaded with NQ14 against the B16F10 melanoma cell line was confirmed through in vitro cytotoxicity studies assessed via MTT assay. The anti-proliferative effect of prepared membranes was directly related to the amount of cross-linker and among all membranes prepared, such that one crosslinked with 0.3% of TPP may become a potential delivery system for releasing NQ14 drug for cancer therapy.

Synthesis of Selenium-Quinone Hybrid Compounds with Potential Antitumor Activity via Rh-Catalyzed C-H Bond Activation and Click Reactions

In continuation of our quest for new redox-modulating catalytic antitumor molecules, selenium-containing quinone-based 1,2,3-triazoles were synthesized using rhodium-catalyzed C-H bond activation and click reactions. All compounds were evaluated against five types of cancer cell lines: HL-60 (human promyelocytic leukemia cells), HCT-116 (human colon carcinoma cells), SF295 (human glioblastoma cells), NCIH-460 (human lung cells) and PC3 (human prostate cancer cells). Some compounds showed good activity with IC50 values below 1 µM. The cytotoxic potential of the naphthoquinoidal derivatives was also evaluated in non-tumor cells, exemplified by L929 cells. Overall, these compounds represent promising new lead derivatives and stand for a new class of chalcogenium-containing derivatives with potential antitumor activity.

Synthesis and anti-proliferative activity evaluation of novel 1,4-naphthoquinones possessing pyrido[2,3-d]pyrimidine scaffolds

A series of novel 1,4-naphthoquinones possessing pyrido[2,3-d]pyrimidine scaffolds were synthesized and most of the compounds exhibited excellent anti-proliferative activities.

Synthesis andIn VitroBiological Evaluation of Aminonaphthoquinones and Benzo[b]phenazine-6,11-dione Derivatives as Potential Antibacterial and Antifungal Compounds

A series of 2-arylamino-3-chloro-1,4-naphthoquinone derivatives (3a–h) by the reaction of 2,3-dichloro-1,4-naphthoquinone with aryl amines (2a–h) and benzo[b]phenazine-6,11-dione derivatives (4a–c) by the treatment of 2-arylamino-3-chloro-1,4-naphthoquinone derivatives (3a–h) with sodium azide were synthesized and tested for theirin vitroantibacterial and antifungal activities. The results suggest that compounds3dand3ghad potent antifungal activity againstCandida albicans(MIC = 78.12 μg/mL). All synthesized compounds (3a–h,4a–c) possessed activity againstE. faecaliswith MIC values of between 312.5 and 1250 μg/mL. Benzo[b]phenazine-6,11-dione derivatives (4a–c) were mostly active against Gram-positive bacteria. The structures of the new members of the series were established on the basis of their spectral properties (IR,1H NMR,13C NMR, and mass spectrometry).

Understanding cancer and the anticancer activities of naphthoquinones – a review

Naphthoquinone moieties are present in drugs such as doxorubicin which are used clinically to treat solid cancers.

l-Proline catalyzed three-component synthesis of para-naphthoquinone–4-aza-podophyllotoxin hybrids as potent antitumor agents

A series of novelpara-naphthoquinone embodied 4-aza-podophyllotoxin hybrids were synthesized and some of the compounds exhibited excellent antitumor activities.

Anticancer activity and SAR studies of substituted 1,4-naphthoquinones

In this paper, we report the structure-activity relationship studies of substituted 1,4-naphthoquinones for its anticancer properties. 1,4-Naphthoquinone, Juglone, Menadione, Plumbagin and LLL12.1 were used as lead molecules to design PD compounds. Most of the PD compounds showed improved antiproliferative activity in comparison to the lead molecule in prostate (DU-145), breast (MDA-MB-231) and colon (HT-29) cancer cell lines. PD9, PD10, PD11, PD13, PD14 and PD15 were found to be the most potent compound with an IC₀ value of 1-3 μM in all cancer cell lines. Fluorescent polarization assay was employed to study the inhibition of STAT3 dimerization by PD compounds. PD9 and PD18 were found to be potent STAT3 dimerization inhibitors.

N-(1,4-Dioxo-1,4-dihydro-naphthalen-2-yl)benzamide

The title compound, C(17)H(11)NO(3), was an inter-mediate synthesized during bis-acyl-ation of 2-amino-1,4-naphtho-quinone with benzoyl chloride. A mixture of block- and needle-shaped crystals were obtained after column chromatography. The block-shaped crystals were identified as the imide and the needles were the title amide. The naphtho-quinone scaffold is roughly planar (r.m.s. deviation = 0.047 Å for the C atoms). The N-H and C=O bonds of the amide group are anti to each other. A dihedral angle between the naphtho-quinone ring system and the amide group of 3.56 (3)°, accompanied by a dihedral angle between the amide group and the phenyl group of 9.51 (3)°, makes the naphtho-quinone ring essentially coplanar with the phenyl ring [dihedral angle = 7.12 (1)°]. In the crystal, molecules are linked by a weak N-H⋯O hydrogen bond and by two weak C-H⋯O interactions leading to the formation of zigzag chains along [010].

Antitrypanosomal activities and cytotoxicity of some novel imido-substituted 1,4-naphthoquinone derivatives

The antitrypanosomal activities, cytotoxicity, and selectivity indices of eleven imido-substituted 1,4-naphthoquinone derivatives and nifurtimox have been studied. Compared to nifurtimox (IC(50) = 10.67 μM), all the imido-naphthoquinone analogs (IMDNQ1-IMDNQ11) are more potent on Trypanosoma cruzi with IC50 values ranging from 0.7 μM to 6.1 μM (p < 0.05). Studies of the cytotoxic activities of these compounds on a Balb/C 3T3 mouse fibroblast cell line revealed that four of these compounds, IMDNQ1, IMDNQ2, IMDNQ3, and IMDNQ10 displayed selectivity indices of 60.25, 53.97, 31.83, and 275.3, respectively, rendering them significantly (p < 0.05) more selective in inhibiting the parasite growth than nifurtimox (selectivity index = 10.86).

N-(3-Bromo-1,4-dioxo-1,4-dihydro-2-naphth-yl)-4-fluoro-N-(4-fluoro-benzo-yl)benzamide

In the title compound, C₂₄H₁₂BrF₂NO₄, synthesized from 2-amino-3-bromo-1,4-naphthoquinone and 4-fluoro­benzoyl chloride, the two p-fluoro­phenyl rings are inclined at 73.9 (1) and 73.6 (1)° to the naphthoquinone ring system. The two imido carbonyl O atoms are anti to each other, while the fluoro­phenyl rings are located opposite each other, connected to the imide group in a funnel-like arrangement. This conformation allows the fluorine groups be oriented slightly away from each other. An examination of the packing shows a close inter­molecular F⋯O contact of 2.982 (5) Å and a Br⋯O contact of 2.977 (4) Å. In addition, the mol­ecules are linked by weak inter­molecular C—H⋯O and C—H⋯F inter­actions.

2-Chloro-3-(4-chloro-benzamido)-1,4-naphthoquinone

The naphthoquinone ring is almost perpendicular [dihedral angle 71.02 (3)°] to the phenyl group of the title compound, C(17)H(9)Cl(2)NO(3), while the dihedral angle between the amide group and the 4-chloro-phenyl ring is 21.9 (2)°. The conformation of the N-H and C=O bonds are anti to each other. N-H⋯Cl hydrogen bonds link the mol-ecules into chains in the a-axis direction. In addition, these chains are linked by weak inter-molecular C-H⋯O inter-actions.

N-(3-Bromo-1,4-dioxo-1,4-dihydro-2-naphth-yl)-2-chloro-N-(2-chloro-benzoyl)benzamide

The title compound, C(24)H(12)BrCl(2)NO(4), was synthesized from 2-amino-3-bromo-1,4-naphthoquinone and 2-chloro-benzoyl chloride. The crystal structure shows that each of the chloro-phenyl rings is inclined at about 60° to the naphthoquinone ring system. The two chloro-phenyl rings adopt a conformation that ensures that chlorine substituents are anti so as to reduce electronic repulsion. An examination of the packing shows close O⋯Br and Cl⋯Cl contacts of 2.947 (2) and 3.346 (1) Å, respectively. In addition, the molecules are linked by weak intermolecular C-H⋯O and C-H⋯Cl interactions.

Elucidation of structure–activity relationships for 2- or 6-substituted-5,8-dimethoxy-1,4-naphthoquinones

1,4-Naphthoquinones have already been recognized to possess a wide range of biological activities. We have developed quantitative structure activity relationships (QSAR) for different series of 2- or 6-substituted-5,8-dimethoxy-1,4-naphthoquinones to understand the chemical-biological interaction governing antiproliferative/cytotoxic activities against L1210 cells. QSAR results have shown that these activities of 2- or 6-substituted-5,8-dimethoxy-1,4-naphthoquinones depend largely on their hydrophobicity.

Synthesis and MEK1 inhibitory activities of imido-substituted 2-chloro-1,4-naphthoquinones

Mitogen activated protein kinases are of interest as research tools and as therapeutic target for certain physiological disorders. In this study, we found 2-chloro-3-(N-succinimidyl)-1,4-naphthoquinone 6 to be a selective inhibitor of MEK1 with an IC(50) of 0.38 microM. An open-chain homologue, 10, showed selective cytotoxicity against renal cancer in the NCI in vitro tumor screening. Structure-activity relationship study of eight compounds showed the cyclic imido-substituted chloro-1,4-naphthoquinone as more potent and selective MEK1 inhibitors than the open chain homologues. The imido-substituted chloro-1,4-naphthoquinones were synthesized in a straightforward fashion by refluxing 2-amino-3-chloro-1,4-naphthoquinone with the appropriate acid chloride or diacyl dichloride.