Fluorinated 3,6,9-trisubstituted acridine derivatives as DNA interacting agents and topoisomerase inhibitors with A549 antiproliferative activity

Exploring the therapeutic potential of acridines: Synthesis, structure, and biological applications

The objective of this review was to explore the trends and chemical characteristics of acridines and their derivatives, analyze their contribution to the scientific literature and international cooperation, identify the most influential authors and articles, and provide an overview of the knowledge produced in elucidating their mechanisms of action. To this end, a bibliometric analysis was performed using RStudio software, along with a systematic review focusing on articles indexed in the "Web of Science" and "Scopus" databases. The keywords used were "acridine$", "Synthesi$", "Structure$", and "Biologic* Application$" for the period from 2020 to 2024. Relevant articles were carefully selected from these databases, and a bibliometric analysis was carried out to comprehensively discuss the most relevant biological activities associated with acridines. The results showed that, during the analyzed period, China and India led in the number of publications, followed by Brazil in third place. However, a decline in the number of publications was observed in the last two years of the period. Keyword analysis revealed that antitumor activity remains the most extensively studied aspect of acridines and their derivatives.

Synthesis of New Chromen-5-one Derivatives from Dimedone and their Antiproliferative Evaluations against Selected Cancer Cell Lines Together with Hepatocellular Carcinoma and Cervical Carcinoma

BACKGROUND

The coumarin nuclei, which exist in many heterocyclic compounds, has gained a lot of attention over the past decade due to their wide range of biological activities such as antibacterial, anticoagulant, antiviral, antifungal, anticancer, and anti-inflammatory properties.

OBJECTIVE

The multi-component reactions of 5,5-dimethylcyclohexane-1,3-dione with acetophenone derivatives and triethoxymethane produced biologically active target chromene molecules and their fused derivatives.

METHODS

The reaction of 5,5-dimethylcyclohexane-1,3-dione and each of triethoxymethane and acetophenone derivatives 3a-g in absolute ethanol containing triethylamine gave the 4,6,7,8-tetrahydro-5H-chromen-5-one derivatives 4a-g. Compounds 4a-d were used for further heterocyclization reactions to produce biologically active fused pyrazole, thiophene, and thiazole derivative corporate with the chromenes caffold.

RESULTS

The cytotoxicity of the synthesized compounds were evaluated using six cancer cell lines together with c-Met kinase and PC-3 cell line inhibitions. In addition, cytotoxicity toward hepatocellular carcinoma HepG2 and cervical carcinoma HeLa was carried out as well as the in-vitro cytotoxic potential for all compounds against peripheral blood lymphocytes (PBL) extracted from healthy donors. Morphological changes of the A549 cell line by the two most active compounds were also studied.

CONCLUSION

The synthesized heterocyclic compounds were originally obtained from 5,5-dimethylcyclohexane- 1,3-dione. Several of the produced compounds exhibited high inhibitions toward several cancer cell lines proving high inhibitions, therefore, encouraging further studies to synthesize heterocyclic compounds based on chromene scaffold.

In vitro detection of cancer cells using a novel fluorescent choline derivative

INTRODUCTION

The treatment of preinvasive lesions is more effective than treating invasive disease, hence detecting cancer at its early stages is crucial. However, currently, available screening methods show various limitations in terms of sensitivity, specificity, and practicality, thus novel markers complementing traditional cyto/histopathological assessments are needed. Alteration in choline metabolism is a hallmark of many malignancies, including cervical and breast cancers. Choline radiotracers are widely used for imaging purposes, even though many risks are associated with their radioactivity. Therefore, this work aimed to synthesise and characterise a non-radioactive choline tracer based on a fluorinated acridine scaffold (CFA) for the in vitro detection of cervical and breast cancer cells by fluorescence imaging.

METHODS

CFA was fully characterised and tested for its cytotoxicity on breast (MCF-7), cervical (HeLa), glioblastoma (U-87 MG) and hepatoblastoma (HepG2) cancer cell lines and in normal cell lines (epithelial, HEK-293 and human dermal fibroblasts, HDFs). The cellular uptake of CFA was investigated by a confocal microscope and its accumulation was quantified over time. The specificity of CFA over mesenchymal origin cells (HDFs), as a model of cancer-associated fibroblasts was investigated by fluorescence microscopy.

RESULTS

CFA was toxic at much higher concentrations (HeLa IC50 = 200 ± 18 µM and MCF-7 IC50 = 105 ± 3 µM) than needed for its detection in cancer cells (5 µM). CFA was not toxic in the other cell lines tested. The intensity of CFA in breast and cervical cancer cells was not significantly different at any time point, yet it was greater than HepG2 and U-87 MG (p ≤ 0.01 and p ≤ 0.0001, respectively) after 24 h incubation. A very weak signal intensity was recorded in HEK-293 and HDFs (p ≤ 0.001 and p ≤ 0.0001, respectively). A selective ability of CFA to accumulate in HeLa and MCF-7 was recorded upon co-culture with fibroblasts.

CONCLUSIONS

The results showed that CFA preferentially accumulated in cancer cells rather than in normal cells. These findings suggest that CFA may be a potential diagnostic probe for discriminating healthy tissues from malignant tissues due to its specific and highly sensitive features; CFA may also represent a useful tool for in vitro/ex vivo investigations of choline metabolism in patients with cervical and breast cancers.

Anti-proliferative, Morphological and Molecular Docking Studies of New Thiophene Derivatives and their Strategy in Ionic Liquids Immobilized Reactions

BACKGROUND

A number of research were conducted on the pyran and thiophene derivatives, which were attributed to have a wide range of biological activities, including anti-plasmodial, as well as acting as caspase, hepatitis C and cancer inhibitors.

OBJECTIVE

The multicomponent reactions of the 5-acetyl-2-amino-4-(phenylamino)-thiophene-3-carbonitrile produced biologically active target molecules like pyran and their fused derivatives. Comparison between regular catalytic multi-component reactions and solvent-free ionic liquids immobilized multicomponent was studied.

METHODS

The multicomponent reactions in this work were carried out not only under the reflux conditions using triethylamine as a catalyst but also in solvent-free ionic liquids immobilized magnetic nanoparticles (MNPs) catalysts.

RESULTS

Through this work, thirty-one new compounds were synthesized and characterized and were evaluated toward the six cancer cell lines, namely A549, HT-29, MKN-45, U87MG, and SMMC-7721 and H460. The most active compounds were further screened toward seventeen cancer cell lines classified according to the disease. In addition, the effect of compound 11e on the A549 cell line was selected to make further morphological changes in the cell line. The Molecular docking studies of 11e and 11f were carried and promising results were obtained.

CONCLUSION

The synthesis of heterocyclic compounds derived from thiophene derivatives has been receiving significant attention. After a detailed optimizing study, it has been found that the solvent-free ionic liquids immobilized multi-component syntheses afforded a high yield of compounds, opening a greener procedure for this synthetically relevant transformation. Many of the synthesized compounds can be considered anticancer agents, enhancing further studies.

Ionic Liquids Immobilized Synthesis of New Xanthenes Derivatives and their Antiproliferative, Molecular Docking, and Morphological Studies

BACKGROUND

Xanthenes and benzoxanthenesare are highly valuable compounds in organic chemistry and medicinal chemistry. Xanthene derivatives were found to have many applications in medicinal chemistry.

OBJECTIVE

This work aims to explore the synthesis of xanthene derivatives with various substituents and find the possibility of their uses as anticancer agents.

METHODS

The basic starting compound through this work was the 2,3-dihydro-1H-xanthen-1-one (3), which was synthesized from the reaction of cyclohexan-1,3-dione and 2-hydroxybenzaldehyde. Compound 3 was used to synthesize new thiophene, pyrimidine, isoxazole, and thiazole derivatives based on the xanthenes nucleus. Fused xanthene derivatives were obtained through further heterocyclization reactions. Multicomponent reactions expressed in this work were carried out in the presence of solvent catalyzed by Et3N and in solvent-free ionic liquid immobilized catalyst.

RESULTS

Cytotoxicity for the newly synthesized compounds toward cancer cell lines was measured, and the results revealed that many compounds exhibited high inhibitions.

CONCLUSION

The antiproliferative activity of the synthesized compounds was studied on six selected cancer cell lines. The nature of the heterocyclic ring and the variations of substituted groups showed a high effect through the inhibitions of the tested compound.

Study of nitrogen heterocycles as DNA/HSA binder, topoisomerase inhibitors and toxicological safety

Four new nitrogen-containing heterocyclic derivatives (acridine, quinoline, indole, pyridine) were synthesized and their biological properties were evaluated. The compounds showed affinity for DNA and HSA, with CAIC and CAAC displaying higher binding constants (Kb) of 9.54 × 104 and 1.06 × 106, respectively. The fluorescence quenching assay (Ksv) revealed suppression values ranging from 0.34 to 0.64 × 103 M-1 for ethidium bromide (EB) and 0.1 to 0.34 × 103 M-1 for acridine orange (AO). Molecular docking confirmed the competition of the derivatives with intercalation probes at the same binding site. At 10 μM concentrations, the derivatives inhibited topoisomerase IIα activity. In the antiproliferative assays, the compounds demonstrated activity against MCF-7 and T47-D tumor cells and nonhemolytic profile. Regarding toxicity, no acute effects were observed in the embryos. However, some compounds caused enzymatic and cardiac changes, particularly the CAIC, which increased SOD activity and altered heart rate compared to the control. These findings suggest potential antitumor action of the derivatives and indicate that substituting the acridine core with different cores does not interfere with their interaction and topoisomerase inhibition. Further investigations are required to assess possible toxicological effects, including reactive oxygen species generation.

DNA Intercalators as Anticancer Agents

Cancer is one of the most prevailing disease conditions which occurs due to uncontrolled cell division either due to natural mutation to the genes or due to changes induced by physical, chemical, or biological carcinogens. According to WHO, it is the second leading cause of death worldwide and has reported 10 million deaths in 2020. Hence there arises the need for better chemotherapies and DNA intercalators are one such emerging therapy for cancer. DNA intercalating agents reversibly intercalate with the double-helical structure of DNA by interacting with adjacent base pairs and disrupting the structure of DNA and thereby causing cell death. Here we discuss the different classes of organo-intercalators used in cancer therapy describing their anticancer and intercalation ability by different methods along with their structure-activity relationship and mechanism of action.

Acridine Based N-Acylhydrazone Derivatives as Potential Anticancer Agents: Synthesis, Characterization and ctDNA/HSA Spectroscopic Binding Properties

A series of novel acridine N-acylhydrazone derivatives have been synthesized as potential topoisomerase I/II inhibitors, and their binding (calf thymus DNA—ctDNA and human serum albumin—HSA) and biological activities as potential anticancer agents on proliferation of A549 and CCD-18Co have been evaluated. The acridine-DNA complex 3b (-F) displayed the highest Kb value (Kb = 3.18 × 103 M−1). The HSA-derivatives interactions were studied by fluorescence quenching spectra. This method was used for the calculation of characteristic binding parameters. In the presence of warfarin, the binding constant values were found to decrease (KSV = 2.26 M−1, Kb = 2.54 M−1), suggesting that derivative 3a could bind to HSA at Sudlow site I. The effect of tested derivatives on metabolic activity of A549 cells evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay decreased as follows 3b(-F) > 3a(-H) > 3c(-Cl) > 3d(-Br). The derivatives 3c and 3d in vitro act as potential dual inhibitors of hTopo I and II with a partial effect on the metabolic activity of cancer cells A594. The acridine-benzohydrazides 3a and 3c reduced the clonogenic ability of A549 cells by 72% or 74%, respectively. The general results of the study suggest that the novel compounds show potential for future development as anticancer agents.

Evolution of Acridines and Xanthenes as a Core Structure for the Development of Antileishmanial Agents

Nowadays, leishmaniasis constitutes a public health issue in more than 88 countries, affecting mainly people from the tropics, subtropics, and the Mediterranean area. Every year, the prevalence of this infectious disease increases, with the appearance of 1.5–2 million new cases of cutaneous leishmaniasis and 500,000 cases of visceral leishmaniasis, endangering approximately 350 million people worldwide. Therefore, the absence of a vaccine or effective treatment makes the discovery and development of new antileishmanial therapies one of the focuses for the scientific community that, in association with WHO, hopes to eradicate this disease shortly. This paper is intended to highlight the relevance of nitrogen- and oxygen-containing tricyclic heterocycles, particularly acridine and xanthene derivatives, for the development of treatments against leishmaniasis. Thus, in this review, a thorough compilation of the most promising antileishmanial acridine and xanthene derivatives is performed from both natural and synthetic origins. Additionally, some structure–activity relationship studies are also depicted and discussed to provide insight into the optimal structural features responsible for these compounds’ antileishmanial activity.

Acridine derivatives as inhibitors/poisons of topoisomerase II

The potential of acridines (amsacrine) as a topoisomerase II inhibitor or poison was first discovered in 1984, and since then, a considerable number of acridine derivatives have been tested as topoisomerase inhibitors/poisons, containing different substituents on the acridine chromophore. This review will discuss a series of studies published over the course of the last decade, which have investigated various novel acridine derivatives against topoisomerase II activity.

Quinoline anticancer agents active on DNA and DNA-interacting proteins: From classical to emerging therapeutic targets

Quinoline is one of the most important and versatile nitrogen heterocycles embodied in several biologically active molecules. Within the numerous quinolines developed as antiproliferative agents, this review is focused on compounds interfering with DNA structure or with proteins/enzymes involved in the regulation of double helix functional processes. In this light, a special focus is given to the quinoline compounds, acting with classical/well-known mechanisms of action (DNA intercalators or Topoisomerase inhibitors). In particular, the quinoline drugs amsacrine and camptothecin (CPT) have been studied as key lead compounds for the development of new agents with improved PK and tolerability properties. Moreover, notable attention has been paid to the quinoline molecules, which are able to interfere with emerging targets involved in cancer progression, as G-quadruplexes or the epigenetic ones (e.g.: histone deacetylase, DNA and histones methyltransferase). The antiproliferative and the enzymatic inhibition data of the reviewed compounds have been analyzed. Furthermore, concerning the SAR (structure-activity relationship) aspects, the most recurrent ligand-protein interactions are summarized, underling the structural requirements for each kind of mechanism of action.

Design, synthesis and antiproliferative evaluation of new tricyclic fused thiazolopyrimidines targeting topoisomerase II: Molecular docking and apoptosis inducing activity

A novel series of thiazolopyrimidines and fused thiazolopyrimidines was designed and synthesized as topoisomerase II alpha inhibitors. All synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compound 3a was found to be the most potent inhibitor on renal cell line (A-498) causing 83.03% inhibition (IC₅₀ = 1.89 μM). DNA-flow cytometric analysis showed that compound 3a induce cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Moreover, fused thiazolopyrimidines 3a showed potent topoisomerase II inhibitory activity (IC₅₀ = 3.19 μM) when compared with reference compound doxorubicin (IC₅₀ = 2.67 μM). Docking study of all the synthesized compounds showed that compound 3a interacts in a similar pattern to etoposide and stabilizing the topoisomerase cleavage complex (Top2-cc) that accounts for its high potency.

Synthesis, anticancer evaluation and molecular docking studies of new benzimidazole- 1,3,4-oxadiazole derivatives as human topoisomerase types I poison

In this study, some benzimidazole-oxadiazole derivatives were synthesised and tested for their in vitro anticancer activities on five cancer cell lines, including HeLa, MCF7, A549, HepG2 and C6. Their structures were elucidated by IR, ¹H-NMR, ¹³C-NMR, 2 D-NMR and HRMS spectroscopic methods. Among all screened compounds; 5a, 5b, 5d, 5e, 5k, 5l, 5n and 5o exhibited potent selective cytotoxic activities against various tested cancer cell lines. Especially, compounds 5l and 5n exhibited the most antiproliferative activity than Hoechst 33342 and doxorubicin against HeLa cell line, with IC₅₀ of 0.224 ± 0.011 µM and 0.205 ± 0.010 µM, respectively. Furthermore, these potent lead cytotoxic agents were evaluated in terms of their inhibition potency against Topoisomerase I and it was determined that selected compounds inhibited the Topoisomerase I. Docking studies were performed and probable interactions in the DNA-Topo I enzyme complex was determined.