Anthraquinone–chalcone hybrids: Synthesis, preliminary antiproliferative evaluation and DNA-interaction studies

Cytotoxic potential of dihydrochalcones from Eriosema glomeratum and their semi-synthetic derivatives

In the search of cytotoxic dihydrochalcones, this investigation led to the isolation of seven compounds (1-7) from Eriosema glomeratum and the preparation of eight derivatives (8-15). The cytotoxicity of samples was evaluated against lung (A549), breast (MCF-7), and cervical (HeLa) human cancer cells. The CH2Cl2/MeOH extract of the aerial part had strong cytotoxicity against all cells [IC50 11.2 (MCF-7), 8.4 (HeLa) and 13.1 (A549) μg/mL]. A strong activity was also displayed by the n-hexane fraction on MCF-7 (IC50 11.2 μg/mL). The precursor 3 and the derivative 8 were specifically found as strong cytotoxic agents toward MCF-7 (7.6 μM) and HeLa (3.1 μM), respectively and were more effective than the positive control. Derivatives 8 (3.1 μM) and 9 (21.3 μM) against HeLa were most potent than their precursor 3 (23.7 μM). This is the first preparation of 8-14 as well as the cytotoxicity of 3, 4, 8-15, fractions, and extract.

Concept of Hybrid Drugs and Recent Advancements in Anticancer Hybrids

Cancer is a complex disease, and its treatment is a big challenge, with variable efficacy of conventional anticancer drugs. A two-drug cocktail hybrid approach is a potential strategy in recent drug discovery that involves the combination of two drug pharmacophores into a single molecule. The hybrid molecule acts through distinct modes of action on several targets at a given time with more efficacy and less susceptibility to resistance. Thus, there is a huge scope for using hybrid compounds to tackle the present difficulties in cancer medicine. Recent work has applied this technique to uncover some interesting molecules with substantial anticancer properties. In this study, we report data on numerous promising hybrid anti-proliferative/anti-tumor agents developed over the previous 10 years (2011–2021). It includes quinazoline, indole, carbazole, pyrimidine, quinoline, quinone, imidazole, selenium, platinum, hydroxamic acid, ferrocene, curcumin, triazole, benzimidazole, isatin, pyrrolo benzodiazepine (PBD), chalcone, coumarin, nitrogen mustard, pyrazole, and pyridine-based anticancer hybrids produced via molecular hybridization techniques. Overall, this review offers a clear indication of the potential benefits of merging pharmacophoric subunits from multiple different known chemical prototypes to produce more potent and precise hybrid compounds. This provides valuable knowledge for researchers working on complex diseases such as cancer.

Synthesis and biological activity, and molecular modelling studies of potent cytotoxic podophyllotoxin-naphthoquinone compounds

A new approach for the synthesis of podophyllotoxin-naphthoquinone compounds using microwave-assisted three-component reactions is reported in this study. Novel podophyllotoxin-naphthoquinone derivatives with modification on ring E were synthesized. All the synthetic compounds were assessed in terms of their cytotoxicity profile against four cancer cell lines (KB, HepG2, A549, and MCF7), and noncancerous Hek-293 cell lines. Notably, treatment of SK-LU-1 cells with compounds 5a and 5b resulted in G2/M phase arrest of the cell cycle, caspase-3/7 activation, and apoptosis. Additionally, molecular docking studies were performed and showed important interaction of two compounds against residues in the colchicine-binding-site of tubulin as well. Taken together, compounds 5a and 5b were identified as potent anticancer agents.

A new approach for the synthesis of podophyllotoxin-naphthoquinone compounds using microwave-assisted three-component reactions is reported in this study.

Design, synthesis, molecular docking and in silico ADMET profile of pyrano[2,3-d]pyrimidine derivatives as antimicrobial and anticancer agents

Pyrano[2,3-d]pyrimidine derivatives were synthesized by treating cyclic compounds containing active methylene group with aldehyde and malononitrile in butanol. The behavior of pyrano[2,3-d]pyrimidine towards some electrophlies namely triethylorthoformate followed by nitrogen nucleophiles as isobutylamine, urea, phenylthiourea, p-toluidine, o-phenylenediamine, o-aminophenol, 2-amino-4-methyl-pyridine and acetic acid with the aim of obtaining some interesting non-mixed heterocyclic compounds. All synthesized compounds to some extent have shown good antimicrobial activity against different microbial strains that had been extracted by inhibiting cell wall synthesis. Compound 5b showed the highest antibacterial activities against B. subtilis, S. aureus and E. coli. On the other hand compound 5 g exhibited the highest antibacterial and antifungal activities against P. aeruginosa and A. niger respectively. In addition, they explore cytotoxic potentialities against different cell lines via DNA intercalation and Top-II inhibition. The cytotoxic activities clarify the strong inhibitory activity of derivative 5a against HepG2 cells with IC₅₀ = 2.09 μM, while HCT-116 cells were highly susceptible to derivative 5c with IC₅₀ = 2.61 μM, in the meantime, derivative 5f showed pronounced negative impact against MCF-7 (IC₅₀ = 2.43 μM) when compared with other prepared compounds. All derivatives exhibited higher anticancer activities than doxorubicin against the three cell lines except compound 2 against both HepG2 and MCF-7 and compound 5e against HepG2 cell lines. Compounds 5a, 5c and 5f potently intercalate DNA at IC₅₀ values of 26.96, 27.13 and 29.86 µM respectively, which were more potent than doxorubicin (IC₅₀ value of 31.27 µM). Moreover, compounds 5a, 5c and 5f exhibited very good Topoisomerase II inhibitory activities with IC₅₀ values of 0.752, 0.791 and 0.776 µM respectively, that were more potent than that of doxorubicin (IC₅₀ = 0.94 µM). For a great extent, the molecular modeling studies were in agreement with that of in vitro cytotoxicity activity, DNA binding and Top-II inhibition results.

Chalcone Derivatives: Role in Anticancer Therapy

Chalcones (1,3-diaryl-2-propen-1-ones) are precursors for flavonoids and isoflavonoids, which are common simple chemical scaffolds found in many naturally occurring compounds. Many chalcone derivatives were also prepared due to their convenient synthesis. Chalcones as weandhetic analogues have attracted much interest due to their broad biological activities with clinical potentials against various diseases, particularly for antitumor activity. The chalcone family has demonstrated potential in vitro and in vivo activity against cancers via multiple mechanisms, including cell cycle disruption, autophagy regulation, apoptosis induction, and immunomodulatory and inflammatory mediators. It represents a promising strategy to develop chalcones as novel anticancer agents. In addition, the combination of chalcones and other therapies is expected to be an effective way to improve anticancer therapeutic efficacy. However, despite the encouraging results for their response to cancers observed in clinical studies, a full description of toxicity is required for their clinical use as safe drugs for the treatment of cancer. In this review, we will summarize the recent advances of the chalcone family as potential anticancer agents and the mechanisms of action. Besides, future applications and scope of the chalcone family toward the treatment and prevention of cancer are brought out.

Study on the Interaction of 4'-Hydroxychalcones and their Mannich Derivatives with Calf Thymus DNA by TLC and Spectroscopic Methods, a DNA Cleavage Study

Background:

Phenolic Mannich bases derived from hydroxychalcones show remarkable cytotoxic potencies towards cancer cell lines. However, the exact mechanism of action is still partially uncleared.

Objective:

Interaction of two hydroxychalcones and their Mannich derivatives with calf thymus DNA (ctDNA) has been investigated.

Methods:

Thin-layer chromatography and UV-Vis spectroscopic method were used for studying the interaction. The binding constant has been determined by UV-Vis spectrophotometric titration. The DNA cleavage activity of the compounds was studied by agarose gel electrophoresis.

Results:

Interaction of the compounds with ctDNA exhibited relatively high intrinsic binding constant (4-5x104 M-1). The results indicate existence of weak, non-covalent interactions between the investigated derivatives with ctDNA. Some compounds showed a slight DNA cleavage activity with pBR322.

Conclusion:

The obtained results provide additional knowledge on the previously documented cytotoxicity against tumor cell lines of the hydroxychalcones and their Mannich-derivatives.

Hybrid Compounds & Oxidative Stress Induced Apoptosis in Cancer Therapy

Elevated Reactive Oxygen Species (ROS) generated by the conventional cancer therapies and the endogenous production of ROS have been observed in various types of cancers. In contrast to the harmful effects of oxidative stress in different pathologies other than cancer, ROS can speed anti-tumorigenic signaling and cause apoptosis of tumor cells via oxidative stress as demonstrated in several studies. The primary actions of antioxidants in cells are to provide a redox balance between reduction-oxidation reactions. Antioxidants in tumor cells can scavenge excess ROS, causing resistance to ROS induced apoptosis. Various chemotherapeutic drugs, in their clinical use, have evoked drug resistance and serious side effects. Consequently, drugs having single-targets are not able to provide an effective cancer therapy. Recently, developed hybrid anticancer drugs promise great therapeutic advantages due to their capacity to overcome the limitations encountered with conventional chemotherapeutic agents. Hybrid compounds have advantages in comparison to the single cancer drugs which have usually low solubility, adverse side effects, and drug resistance. This review addresses two important treatments strategies in cancer therapy: oxidative stress induced apoptosis and hybrid anticancer drugs.

Chalcone hybrids as potential anticancer agents: Current development, mechanism of action, and structure-activity relationship

The continuous emergency of drug-resistant cancers and the low specificity of anticancer agents have been the major challenges in the control and treatment of cancer, making an urgent need to develop novel anticancer agents with high efficacy. Chalcones, precursors of flavonoids and isoflavonoids, exhibit structural heterogeneity and can act on various drug targets. Chalcones which demonstrated potential in vitro and in vivo activity against both drug-susceptible and drug-resistant cancers, are useful templates for the development of novel anticancer agents. Hybridization of chalcone moiety with other anticancer pharmacophores could provide the hybrids which have the potential to overcome drug resistance and improve the specificity, so it represents a promising strategy to develop novel anticancer agents. This review emphasizes the development, the mechanisms of action as well as structure-activity relationships of chalcone hybrids with potential therapeutic application for many cancers in recent 10 years.

On the in silico and in vitro anticancer activity of sulfonamide chalcones: potential JNKK3 inhibitors

Although many compound classes have been studied as JNK inhibitors, we are interested in using chalcones for this purpose. Do different groups drive to different bindings modes to JNK?

Chalcone as Potential Nonlinear Optical Material: A Combined Theoretical, Structural and Spectroscopic Study

In this work, we propose the synthesis of a novel bromine chalcone (E)-3-(2-bromophenyl)-1-(2phenylsulfonylamine)-phenyl)prop-2-en-1-one (BRC) that has been crystallized by slow evaporation technique. The second order molecular optical scattering and two-photon absorption(2PA) spectrumof the BRC molecule dissolved in Dimethyl Sulfoxide (DMSO) were evaluated by using Hyper Rayleigh Scattering and femtosecond tunable Z-Scan techniques. The first order hyperpolarizability of BRC dissolved in DMSO was estimated by using a simplified two-level model, in which one- and two-photon absorption parameters were used as input information to the model. The BRC crystal was characterized from single crystal X-ray diffraction (DRX) and spectroscopy analyzes. Also, the thermogravimetric analyses and the fluorescence spectra were obtained. In addition, an ab-initio calculation method, which includes the Møller-Plesset Perturbation Theory (MP2) and the Density Functional Theory (DFT) at CAM-B3LYP level,was used to estimate the crystal linear refractive index and the third-order electric susceptibility. Also, the average first hyperpolarizability of BRC molecules dissolved in DMSO was calculated and compared with the experimental results. The obtained values are good and qualify BRC crystal as a potential candidate for application in nonlinear optical devices.

Antiproliferative and proapoptotic activities of aza-annulated naphthoquinone analogs

1,4-Naphthoquinone derivatives have been widely documented with regard to their biological properties, and particularly their anticancer activities. In the 9,10-anthraquinone family, aza-annulation involving one of the carbonyl oxygen atoms has afforded more potent, possibly less toxic analogues. We recently carried out different modifications on the naphthoquinone skeleton to generate 3-chloro-2-amino- and 3-chloro-2-(N-acetamido)-1,4-naphthoquinone and 3,4-dihydrobenzo[f]quinoxalin-6(2H)-one derivatives. These three series of compounds were now tested against normal human fibroblasts and six human cancer cell lines. Some of the dihydrobenzoquinoxalinone derivatives were not only more potent than their 1,4-naphthoquinone counterparts, but also exhibited 10- to 14-fold selectivity between bladder carcinoma and normal cells and were equipotent with the non-selective reference drug used (etoposide). The fusion of an additional azaheterocycle to the 1,4-naphthoquinone nucleus modulates both the activity, selectivity and mechanism of action of the compounds. The electrochemical properties of selected compounds were evaluated in an attempt to correlate them with cytotoxic activity and mechanism of action. Finally, 3D-QSAR CoMFA and CoMSIA models were built on the AGS, J82, and HL-60 cell lines. The best models had values of r²_pred = 0.815; 0.823 and 0.925. The main structural relationships found, suggest that acetylation and alkylation of the amino group with large groups would be beneficial for cytotoxic activity.

Novel hybrids derived from aspirin and chalcones potently suppress colorectal cancer in vitro and in vivo

Colorectal cancer (CRC) remains the fourth leading cause of cancer deaths around the world despite the availability of many approved small molecules for treatment. The issues lie in the potency, selectivity and targeting of these compounds. Therefore, new strategies and targets are needed to optimize and develop novel treatments for CRC. Here, a group of novel hybrids derived from aspirin and chalcones were designed and synthesized based on recent reports of their individual benefits to CRC targeting and selectivity. The most active compound 7h inhibited proliferation of CRC cell lines with better potency compared to 5-fluorouracil, a currently used therapeutic agent for CRC. Importantly, 7h had 8-fold less inhibitory activity against non-cancer CCD841 cells. In addition, 7h inhibited CRC growth via the inhibition of the cell cycle in the G1 phase. Furthermore, 7h induced apoptosis by activating caspase 3 and PARP cleavage, as well as increasing ROS in CRC cells. Finally, 7h significantly retarded the CRC cell growth in a mouse xenograft model. These findings suggest that 7h may have potential to treat CRC.

Novel 1,3,4-thiadiazole-chalcone hybrids containing catechol moiety: synthesis, antioxidant activity, cytotoxicity and DNA interaction studies

Hybrid compounds that combine the 1,3,4-thiadiazole-containing catechol moiety with a chalcone motif were synthesized and examined for their antioxidant activity, cytotoxicity, and DNA-binding activity. A series of thirteen compounds showed strong antioxidant and cytotoxic effects on human acute promyelocytic leukemia HL-60 cells. Several compounds exerted good cytotoxic activities on cervical adenocarcinoma HeLa cells. The treatment of HeLa cells with IC₅₀ and double IC₅₀ concentrations of the compounds 5a, 5c, 5f, and 5m induced a statistically significant increase in the percentage of cells within a subG1 cell cycle phase. The examined compounds caused G2/M cell cycle arrest in HeLa cells. Each of these compounds triggered apoptosis in HeLa cells through activation of caspase-3, the main effector caspase, caspase-8, which is involved in the extrinsic apoptotic pathway, and caspase-9, which is involved in the intrinsic apoptotic pathway. All of the examined compounds decreased the expression levels of MMP2 in HeLa cells and levels of protumorigenic miR-133b. Compounds 5a and 5m lowered the expression level of oncogenic miR-21 in HeLa cells. In addition, compounds 5a, 5f, and 5m decreased the expression levels of oncogenic miR-155 while the treatment of HeLa cells with compounds 5a, 5c, and 5f increased expression of tumor-suppressive miR-206. Observed effects of these compounds on expression levels of four examined miRNAs suggest their prominent cancer-suppressive activity. An investigation by absorption and fluorescence spectroscopy showed more efficient calf thymus DNA binding activity of the compound 5m in comparison to other tested compounds. Results of a pUC19 plasmid cleavage study and comet assay showed DNA damaging activities of compounds 5a and 5c.

Highly selective anthraquinone-chalcone hybrids as potential antileukemia agents

A series of 23 novel anthraquinone-chalcone hybrids containing amide function was synthesized and structurally characterized. Sixteen compounds exerted strong cytotoxic activities against K562, Jurkat and HL-60 leukemia cell lines and significantly lower cytotoxic effects against normal MRC-5 cells, indicating very high selectivity in their anticancer action. The compounds 6g, 6u and 6v activate apoptosis in K562 cells through the extrinsic and intrinsic apoptotic pathway. The compound 6e triggered apoptosis in K562 cells only through the extrinsic apoptotic pathway. Treatment of K562 cells with each of these four compounds caused decrease in the expression levels of MMP2, MMP9, and VEGF, suggesting their anti-invasive, antimetastatic and antiangiogenic properties. The compounds 6g and 6v downregulated expression levels of miR-155 in K562 cells, while compounds 6e and 6u upregulated miR-155 levels in treated cells, in comparison with control cells. The structure-based 3-D QSAR models for 6f, 6e, 6i and 6l describe pro-apoptotic activity against caspase-3.

An overview of recent advances in duplex DNA recognition by small molecules

As the carrier of genetic information, the DNA double helix interacts with many natural ligands during the cell cycle, and is amenable to such intervention in diseases such as cancer biogenesis. Proteins bind DNA in a site-specific manner, not only distinguishing between the geometry of the major and minor grooves, but also by making close contacts with individual bases within the local helix architecture. Over the last four decades, much research has been reported on the development of small non-natural ligands as therapeutics to either block, or in some cases, mimic a DNA–protein interaction of interest. This review presents the latest findings in the pursuit of novel synthetic DNA binders. This article provides recent coverage of major strategies (such as groove recognition, intercalation and cross-linking) adopted in the duplex DNA recognition by small molecules, with an emphasis on major works of the past few years.

Highly selective iodide sensing ability of an anthraquinone-derived Schiff base in semi-aqueous medium and its performance in antioxidation, anti-inflammation and HRBC membrane protection

In this study, a new iodide (I⁻) ion selective chromogenic receptor (3) was developed by reacting 9,10-anthraquinone with 2,4-dinitrophenylhydrazine.

Recent advances (2015-2016) in anticancer hybrids

In spite of the development of a large number of novel anticancer drugs over the years, Cancer remains as a prominent cause of death, worldwide. Numerous drugs that are currently in clinical practice have developed multidrug resistance along with fatal side effects. Therefore, the utilization of single-target therapy is incapable of providing an effective control on the malignant process. Molecular hybridization, involving a combination of two or more pharmacophores of bioactive scaffolds to generate a single molecular architecture with improved affinity and activity, in comparison to their parent molecules, has emerged as a promising strategy in recent drug discovery research. Hybrid anticancer drugs are of great therapeutic interests since they can potentially overcome most of the pharmacokinetic drawbacks encountered with conventional anticancer drugs. Strategically, the design of anticancer drugs involved the blending or linking of an anticancer drug with another anticancer drug or a carrier molecule which can efficiently target cancer cells with improved biological potential. Major advantages of hybrid anticancer drugs involved increased specificity, better patient compliance, and lower side effects along with reduction in chemo-resistance. The successful utilization of this technique in design and synthesis of novel anticancer hybrids has been well illustrated and documented in the literature. The purpose of the present review article will be to provide an emphasis on the recent developments (2015-16) in anticancer hybrids with insights into their structure-activity relationship (SAR) and mechanism of action.

Chalcone: A Privileged Structure in Medicinal Chemistry

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

α-Glucosidase inhibitory activity and cytotoxic effects of some cyclic urea and carbamate derivatives

The inhibitory activities of selected cyclic urea and carbamate derivatives (1-13) toward α-glucosidase (α-Gls) in in vitro assay were examined in this study. All examined compounds showed higher inhibitory activity (IC₅₀) against α-Gls compared to standard antidiabetic drug acarbose. The most potent was benzyl (3,4,5-trimethoxyphenyl)carbamate (12) with IC₅₀ = 49.85 ± 0.10 µM. In vitro cytotoxicity of the investigated compounds was tested on three human cancer cell lines HeLa, A549 and MDA-MB-453 using MTT assay. The best antitumour activity was achieved with compound 2 (trans-5-phenethyl-1-phenylhexahydro-1H-imidazo[4,5-c]pyridin-2(3H)-one) against MDA-MB-453 human breast cancer cell line (IC₅₀ = 83.41 ± 1.60 µM). Cyclic ureas and carbamates showed promising anti-α-glucosidase activity and should be further tested as potential antidiabetic drugs. The PLS model of preliminary QSAR study indicated that, in planing the future synthesis of more potent compounds, the newly designed should have the substituents capable of polar interactions with receptor sites in various positions, while avoiding the increase of their lipophilicity.

Mannich bases of 1,2,4-triazole-3-thione containing adamantane moiety: Synthesis, preliminary anticancer evaluation, and molecular modeling studies

A series of 18 novel N-Mannich bases derived from 5-adamantyl-1,2,4-triazole-3-thione was synthesized and characterized using NMR spectroscopy and X-ray diffraction technique. All derivatives were evaluated for their anticancer potential against four human cancer cell lines. Several tested compounds exerted good cytotoxic activities on K562 and HL-60 cell lines, along with pronounced selectivity, showing lower cytotoxicity against normal fibroblasts MRC-5 compared to cancer cells. The effects of compounds 5b, 5e, and 5j on the cell cycle were investigated by flow cytometric analysis. It was found that these compounds cause the accumulation of cells in the subG1 and G1 phases of the cell cycle and induce caspase-dependent apoptosis, while the anti-angiogenic effects of 5b, 5e, and 5j have been confirmed in EA.hy926 cells using a tube formation assay. Further, the interaction of Bax protein with compound 5b was investigated by means of molecular modeling, applying the combined molecular docking/molecular dynamics approach.

Chalcone Scaffold in Anticancer Armamentarium: A Molecular Insight

Cancer is an inevitable matter of concern in the medicinal chemistry era. Chalcone is the well exploited scaffold in the anticancer domain. The molecular mechanism of chalcone at cellular level was explored in past decades. This mini review provides the most recent updates on anticancer potential of chalcones.

Anti-cancer chalcones: Structural and molecular target perspectives

Chalcone or (E)-1,3-diphenyl-2-propene-1-one scaffold remained a fascination among researchers in the 21st century due to its simple chemistry, ease of synthesis and a wide variety of promising biological activities. Several natural and (semi) synthetic chalcones have shown anti-cancer activity due to their inhibitory potential against various targets namely ABCG2/P-gp/BCRP, 5α-reductase, aromatase, 17-β-hydroxysteroid dehydrogenase, HDAC/Situin-1, proteasome, VEGF, VEGFR-2 kinase, MMP-2/9, JAK/STAT signaling pathways, CDC25B, tubulin, cathepsin-K, topoisomerase-II, Wnt, NF-κB, B-Raf and mTOR etc. In this review, a comprehensive study on molecular targets/pathways involved in carcinogenesis, mechanism of actions (MOAs), structure activity relationships (SARs) and patents granted have been highlighted. With the knowledge of molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective anti-cancer chalcones.