Discovery of Novel Quinoline–Chalcone Derivatives as Potent Antitumor Agents with Microtubule Polymerization Inhibitory Activity

Structural modification strategies of triazoles in anticancer drug development

The triazole functional group plays a pivotal role in the composition of biomolecules with potent anticancer activities, including numerous clinically approved drugs. The strategic utilization of the triazole fragment in the rational modification of lead compounds has demonstrated its ability to improve anticancer activities, enhance selectivity, optimize pharmacokinetic properties, and overcome resistance. There has been significant interest in triazole-containing hybrids in recent years due to their remarkable anticancer potential. However, previous reviews on triazoles in cancer treatment have failed to provide tailored design strategies specific to these compounds. Herein, we present an overview of design strategies encompassing a structure-modification approach for incorporating triazoles into hybrid molecules. This review offers valuable references and briefly introduces the synthesis of triazole derivatives, thereby paving the way for further research and advancements in the field of effective and targeted anticancer therapies.

Synthesis and biological evaluation of 4-phenyl-5-quinolinyl substituted isoxazole analogues as potent cytotoxic and tubulin polymerization inhibitors against ESCC

The identification of chemically different inhibitors that target the colchicine site of tubulin is still of great value for cancer treatment. Combretastatin A-4(CA-4), a naturally occurring colchicine-site binder characterized by its structural simplicity and biological activity, has served as a structural blueprint for the development of novel analogues with improved safety and therapeutic efficacy. In this study, a library of forty-eight 4-phenyl-5-quinolinyl substituted triazole, pyrazole or isoxazole analouges of CA-4, were synthesized and evaluated for their cytotoxicity against Esophageal Squamous Cell Carcinoma (ESCC) cell lines. Compound C11, which features a 2-methyl substitution at the quinoline and carries an isoxazole ring, emerged as the most promising, with 48 h IC50s of less than 20 nmol/L against two ESCC cell lines. The findings from EBI competitive assay, CETA, and in vitro tubulin polymerization assay of C11 are consistent with those of the positive control colchicine, demonstrating the clear affinity of compound C11 to the colchicine binding site. The subsequent cellular-based mechanism studies revealed that C11 significantly inhibited ESCC cell proliferation, arrested cell cycle at the M phase, induced apoptosis, and impeded migration. Experiments conducted in vivo further confirmed that C11 effectively suppressed the growth of ESCC without showing any toxicity towards the selected animal species. Overall, our research suggests that the tubulin polymerization inhibitor incorporating quinoline and the isoxazole ring may deserve consideration for cancer therapy.

Exploring the antitumor potential of novel quinoline derivatives via tubulin polymerization inhibition in breast cancer; design, synthesis and molecular docking

A series of quinoline derivatives was designed and synthesized as novel tubulin inhibitors targeting the colchicine binding site. All the rationalized compounds 3a-e, 4a-e, 5a-e, and 6a-e have been chosen for screening their cytotoxic activity against 60 cell lines by NCI. Compounds 3b, 3c, 4c, 5c and 6c demonstrated the most notable antitumor activity against almost all cell lines. Compound 4c emerged as the most potent compound as an antiproliferative agent. This compound was subsequently chosen for five-dose testing and it exhibited remarkable broad-spectrum efficacy with strong antitumor activity against several cell lines. Compound 4c significantly induced cell cycle arrest in MDA-MB-231 cells at G2 and M phases where the cell population increased dramatically to 22.84% compared to the untreated cells at 10.42%. It also increased the population in MDA-MB-231 cells at both early and late stages of apoptosis. Compound 4c can successfully inhibit tubulin polymerization with an IC50 value of 17 ± 0.3 μM. The β-tubulin mRNA levels were notably reduced in MDA-MB-231 cells treated with compound 4c which is similar to the effect observed with colchicine treatment. Docking studies revealed that compound 4c interacted well with crucial amino acids in the active site.

Significance of Chalcone Scaffolds in Medicinal Chemistry

Chalcone is a simple naturally occurring α,β-unsaturated ketone with biological importance, which can also be easily synthesized in laboratories by reaction between two aromatic scaffolds. In plants, chalcones occur as polyphenolic compounds of different frameworks which are bioactive molecules that have been in traditional medicinal practice for many years. Chalcone-based lead molecules have been developed, possessing varied potentials such as antimicrobial, antiviral, anti-inflammatory, anticancer, anti-oxidant, antidiabetic, antihyperurecemic, and anti-ulcer effects. Chalcones contribute considerable fragments to give important heterocyclic molecules with therapeutic utilities targeting various diseases. These characteristic features have made chalcone a topic of interest among researchers and have attracted investigations into this widely applicable structure. This review highlights the extensive exploration carried out on the synthesis, biotransformations, chemical reactions, hybridization, and pharmacological potentials of chalcones, and aims to provide an extensive, thorough, and critical review of their importance, with emphasis on their properties, chemistry, and biomedical applications to boost future investigations into this potential scaffold in medicinal chemistry.

Design, synthesis and biological evaluation of indoline-maleimide conjugates as potential antitumor agents for the treatment of colorectal cancer

An efficient protocol for direct coupling of maleimides and indolines at the C7-position was achieved under Rh(III) catalysis. Thirty four novel indoline-maleimide conjugates were prepared in good to excellent yields using this method. All compounds were evaluated for their anti-proliferative effect against colorectal cell lines. Among them, compound 3ab showed the most potent anti-proliferative activity against the CRC cells, and displayed low toxicity in the normal cell. Further investigation indicated that 3ab could effectively suppress the proliferation and migration of CRC cells, along with inducing cell cycle arrest and apoptosis. Mechanistic studies revealed that compound 3ab inhibited the proliferation of CRC cells via suppressing the AKT/GSK-3β pathway. In vivo evaluation demonstrated remarkable antitumor effect of 3ab (10 mg/kg) in the HCT116 xenograft model with no obvious toxicity, which is superior to that of 5-Fluorouracil (20 mg/kg). Therefore, conjugate 3ab could be considered as a potential CRC therapy agent for further development.

Current scenario of chalcone hybrids with antibreast cancer therapeutic applications

Breast cancer, an epithelial malignant tumor that occurs in the terminal ducts of the breast, is the most common female malignancy. Currently, approximately 70%-80% of breast cancer with early-stage, nonmetastatic disorder is curable, but the emergency of drug resistance often leads to treatment failure. Moreover, advanced breast cancer with distant organ metastases is incurable with the available therapeutics, creating an urgent demand to explore novel antibreast cancer agents. Chalcones, the precursors for flavonoids and isoflavonoids, exhibit promising activity against various breast cancer hallmarks, inclusive of proliferation, angiogenesis, invasion, metastasis, inflammation, stemness, and regulation of cancer epigenetics, representing useful scaffolds for the discovery of novel antibreast cancer chemotherapeutic candidates. In particular, chalcone hybrids could act on two or more different biological targets simultaneously with more efficacy, lower toxicity, and less susceptibility to resistance. Accordingly, there is a huge scope for application of chalcone hybrids to tackle the present difficulties in breast cancer therapy. This review outlines the chalcone hybrids with antibreast cancer potential developed from 2018. The structure-activity relationships as well as mechanisms of action are also discussed to shed light on the development of more effective and multitargeted chalcone candidates.

Design of Evodiamine-Glucose Conjugates with Improved In Vivo Antitumor Activity

Natural product evodiamine is a multitargeting antitumor lead compound. However, clinical development of evodiamine derivatives was hampered by poor water solubility and limited in vivo antitumor potency. Herein, a series of evodiamine-glucose conjugates were designed by additional targeting glucose transporter-1 (GLUT1). Compared with the lead compound, conjugate 8 exhibited obvious enhancement in water solubility and in vivo antitumor efficacy. Furthermore, the effect of GLUT1 targeting also led to lower cytotoxicity to normal cells. Antitumor mechanism studies manifested that conjugate 8 acted by Top1/Top2 dual inhibition, apoptosis induction, and G2/M cell cycle arrest, which selectively targeted tumor cells with a high expression level of GLUT1. Thus, evodiamine-glucose conjugates showed promising features as potential antitumor agents.

Inhibition of cancer cells by Quinoline-Based compounds: A review with mechanistic insights

This article includes a thorough examination of the inhibitory potential of quinoline-based drugs on cancer cells, as well as an explanation of their modes of action. Quinoline derivatives, due to their various chemical structures and biological activity, have emerged as interesting candidates in the search for new anticancer drugs. The review paper delves into the numerous effects of quinoline-based chemicals in cancer progression, including apoptosis induction, cell cycle modification, and interference with tumor-growth signaling pathways. Mechanistic insights on quinoline derivative interactions with biological targets enlightens their therapeutic potential. However, obstacles such as poor bioavailability, possible off-target effects, and resistance mechanisms make it difficult to get these molecules from benchside to bedside. Addressing these difficulties might be critical for realizing the full therapeutic potential of quinoline-based drugs in cancer treatment.

Novel 4-Aryl-4H-chromene derivative displayed excellent in vivo anti-glioblastoma efficacy as the microtubule-targeting agent

In this study, a series of novel 4-Aryl-4H-chromene derivatives (D1-D31) were designed and synthesized by integrating quinoline heterocycle to crolibulin template molecule based on the strategy of molecular hybridization. One of these compounds D19 displayed positive antiproliferative activity against U87 cancer cell line (IC50 = 0.90 ± 0.03 μM). Compound D19 was verified as the microtubule-targeting agent through downregulating tubulin related genes of U87 cells, destroying the cytoskeleton of tubulins and interacting with the colchicine-binding site to inhibit the polymerization of tubulins by transcriptome analysis, immune-fluorescence staining, microtubule dynamics and EBI competition assays as well as molecular docking simulations. Moreover, compound D19 induced G2/M phase arrest, resulted in cell apoptosis and inhibited the migration of U87 cells by flow cytometry analysis and wound healing assays. Significantly, compound D19 dose-dependently inhibited the tumor growth of orthotopic glioma xenografts model (GL261-Luc) and effectively prolonged the survival time of mice, which were extremely better than those of positive drug temozolomide (TMZ). Compound D19 exhibited potent in vivo antivascular activity as well as no observable toxicity. Furthermore, the results of in silico simulation studies and P-gp transwell assays verified the positive correlation between compound D19's Blood-Brain Barrier (BBB) permeability and its in vivo anti-GBM activity. Overall, compound D19 can be used as a promising anti-GBM lead compound for the treatment of glioblastoma.

A novel L-shaped ortho-quinone analog as PLK1 inhibitor blocks prostate cancer cells in G2 phase

Prostate cancer is the most common malignant tumor among men worldwide. Currently, the main treatments are radical prostatectomy, radiotherapy, chemotherapy, and endocrine therapy. However, most of them are poorly effective and induce side effects. Polo-like kinase 1 (PLK1) regulates cell cycle and mitosis. Its inhibitor BI2536 promotes the therapeutic effect of nilotinib in chronic myeloid leukemia, enhances the sensitivity of neural tube cell tumors to radiation therapy and PLK1 silencing enhances the sensitivity of squamous cell carcinoma to cisplatin. Therefore, the aim of this study was to evaluate the effect of the PLK1 inhibitor L-shaped ortho-quinone analog TE6 on prostate cancer. In vitro on prostate cancer cells showed that TE6 inhibited PLK1 protein expression and consequently cell proliferation by blocking the cell cycle at G2 phase. In vivo on a subcutaneous tumor model in nude mice confirmed that TE6 effectively inhibited tumor growth in nude mice, inhibited PLK1 expression and regulated the expression of cell cycle proteins such as p21, p53, CDK1, Cdc25C, and cyclinB1. Thus, PLK1 was identified as the target protein of TE6, these results reveal the critical role of PLK1 in the growth and survival of prostate cancer and point out the ability of TE6 on targeting PLK1, being a potential drug for prostate cancer therapy.

Design, synthesis and biological evaluation of novel dihydroquinolin-4(1H)-one derivatives as novel tubulin polymerization inhibitors

A series of novel dihydroquinolin-4(1H)-one derivatives targeting colchicine binding site on tubulin were designed, synthesized and evaluated as anticancer agents. The most potent compound 6t showed remarkable antiproliferative activities against four cancer cell lines with IC50 values among 0.003-0.024 μM and tubulin polymerization inhibitory activity (IC50 = 3.06 μM). Further mechanism studies revealed that compound 6t could induce K562 cells apoptosis and arrest at the G2/M phase. Meanwhile, 6t significantly inhibited migration and invasion of MDA-MB-231 cells, and disrupted the angiogenesis in human umbilical vein endothelial cells (HUVECs) in vitro. In addition, compound 6t inhibited tumor growth in H22 allograft tumor model with a tumor growth inhibition (TGI) rate of 63.3 % (i.v., 20 mg/kg per day) without obvious toxicity. Collectively, these results indicated that compound 6t was a novel tubulin polymerization inhibitor with potent anticancer properties in vitro and in vivo.

Design, synthesis and evaluation of dihydro-1H-indene derivatives as novel tubulin polymerisation inhibitors with anti-angiogenic and antitumor potency

Angiogenesis plays an important role in tumour generation and progression, which is used to supply nutrients and metastasis. Herein, a series of novel dihydro-1H-indene derivatives were designed and evaluated as tubulin polymerisation inhibitors by binding to colchicine site, exhibiting anti-angiogenic activities against new vessel forming. Through structure-activity relationships study, compound 12d was found to be the most potent derivative possessing the antiproliferative activity against four cancer lines with IC50 values among 0.028-0.087 µM. Compound 12d bound to colchicine site on tubulin and inhibited tubulin polymerisation in vitro. In addition, compound 12d induced cell cycle arrest at G2/M phase, stimulated cell apoptosis, inhibited tumour metastasis and angiogenesis. Finally, the results of in vivo assay suggested that compound 12d could prevent tumour generation, inhibit tumour proliferation and angiogenesis without obvious toxicity. Collectively, all these findings suggested that compound 12d is a novel tubulin polymerisation inhibitor deserving further research.

Development of QTMP: A promising anticancer agent through NP-Privileged Motif-Driven structural modulation

In this study of creating new molecules from clinical trial agents, an approach of Combretastatin structural modulation with the installation of NP-privileged motifs was considered, and a series of trimethoxyphenyl-2-aminoimidazole with functionalized quinolines and isoquinolines was investigated. An exciting method of quinoline C3-H iodination coupled with imidazopyridine-C3-H arylation and hydrazine-mediated fused-ring cleavage enabled synthesizing a class of compounds with two specific unsymmetric aryl substitutions. Interestingly, three compounds (6, 11, and 13) strongly inhibited HeLa cell proliferation with a half-maximal inhibitory concentration (10-46 nM). Among the compounds, compound 6 (QTMP) showed stronger antiproliferative ability than CA-4 (a clinical trial agent) in various cancer cell lines, including cervical, lung, breast, highly metastatic breast, and melanoma cells. QTMP inhibited the assembly of purified tubulin, depolymerized microtubules of A549 lung carcinoma cells, produced defective spindles, and arrested the cells in the G2/M phase. Further, QTMP binds to the colchicine site in tubulin with a dissociation constant of 5.0 ± 0.6 µM. QTMP displayed higher aqueous stability than CA-4 at 37 °C. Further, in silico analysis of QTMP indicated excellent drug-like properties, including good aqueous solubility, balanced hydrophilicity-lipophilicity, and high GI-absorption ability. The results together suggest that QTMP has anticancer potential.

Design, synthesis and bioevaluation of novel trifluoromethylquinoline derivatives as tubulin polymerization inhibitors

Aim: A series of novel trifluoromethylquinoline derivatives were designed, synthesized and evaluated for antitumor activities. Methodology: All compounds were evaluated for antiproliferative activity against four human cancer cell lines. Results: Among them, 5a, 5m, 5o and 6b exhibited remarkable antiproliferative activities against all the tested cell lines at nanomolar concentrations. Mechanism of action studies demonstrated that 6b targeted the colchicine binding site, potentially inhibiting tubulin polymerization, and further studies indicated that 6b could arrest LNCaP cells in the G2/M phase and induce cell apoptosis. Molecular docking confirmed that 6b could bind to the colchicine binding site. Conclusion: Results suggested that 6b could serve as a promising lead compound for the development of novel tubulin polymerization inhibitors and cancer therapy.

Development of tubulin polymerization inhibitors as anticancer agents

INTRODUCTION

Microtubules are intracellular, filamentous, polymeric structures that extend throughout the cytoplasm, composed of α-tubulin and β-tubulin subunits. They regulate many cellular functions including cell polarity, cell shape, mitosis, intracellular transport, cell signaling, gene expression, cell integrity, and are associated with tumorigenesis. Inhibition of tubulin polymerization within tumor cells represents a crucial focus in the pursuit of developing anticancer treatments.

AREAS COVERED

This review focuses on the natural product and their synthetic congeners as tubulin inhibitors along with their site of interaction on tubulin. This review also covers the developed novel tubulin inhibitors and important patents focusing on the development of tubulin inhibition for cancer treatment reported from 2018 to 2023. The scientific and patent literature has been searched on PubMed, Espacenet, ScienceDirect, and Patent Guru from 2018-2023.

EXPERT OPINION

Tubulin is one of the promising targets explored extensively for drug discovery. Compounds binding in the colchicine site could be given importance because they can elude resistance mediated by the P-glycoprotein efflux pump and no colchicine site binding inhibitor is approved by FDA so far. The research on the development of antibody drug conjugates (ADCs) for tubluin polymerization inhibition could be significant strategy for cancer treatment.

Discovery of novel 2-(trifluoromethyl)quinolin-4-amine derivatives as potent antitumor agents with microtubule polymerization inhibitory activity

In this work, a series of 2-(trifluoromethyl)quinolin-4-amine derivatives were designed and synthesized through structural optimization strategy as a microtubule-targeted agents (MTAs) and their cytotoxicity activity against PC3, K562 and HeLa cell lines were evaluated. The half maximal inhibitory concentration (IC50) of 5e, 5f, and 5o suggested that their potency of anti-proliferative activities against HeLa cell lines were better than the combretastatin A-4. Compound 5e showed the higher anti-proliferative activity against PC3, K562 and HeLa in vitro with IC50 values of 0.49 µM, 0.08 µM and 0.01 µM, respectively. Further mechanism study indicated that the representative compound 5e was new class of tubulin inhibitors by EBI competition assay and tubulin polymerization assays, it is similar to colchicine. Immunofluorescence staining revealed that compound 5e apparently disrupted tubulin network in HeLa cells, and compound 5e arrested HeLa cells at the G2/M phase and induced cells apoptosis in a dose-dependent manner. Molecular docking results illustrated that the hydrogen bonds of represented compounds reinforced the interactions in the pocket of colchicine binding site. Preliminary results suggested that 5e deserves further research as a promising tubulin inhibitor for the development of anticancer agents.

Application of Quinoline Ring in Structural Modification of Natural Products

Natural compounds are rich in pharmacological properties that are a hot topic in pharmaceutical research. The quinoline ring plays important roles in many biological processes in heterocycles. Many pharmacological compounds, including saquinavir and chloroquine, have been marketed as quinoline molecules with good anti-viral and anti-parasitic properties. Therefore, in this review, we summarize the medicinal chemistry of quinoline-modified natural product quinoline derivatives that were developed by several research teams in the past 10 years and find that these compounds have inhibitory effects on bacteria, viruses, parasites, inflammation, cancer, Alzheimer's disease, and others.

Advances of antitumor drug discovery in traditional Chinese medicine and natural active products by using multi-active components combination

The antitumor efficacy of Chinese herbal medicines has been widely recognized. Leading compounds such as sterols, glycosides, flavonoids, alkaloids, terpenoids, phenylpropanoids, and polyketides constitute their complex active components. The antitumor monomers derived from Chinese medicine possess an attractive anticancer activity. However, their use was limited by low bioavailability, significant toxicity, and side effects, hindering their clinical applications. Recently, new chemical entities have been designed and synthesized by combining natural drugs with other small drug molecules or active moieties to improve the antitumor activity and selectivity, and reduce side effects. Such a novel conjugated drug that can interact with several vital biological targets in cells may have a more significant or synergistic anticancer activity than a single-molecule drug. In addition, antitumor conjugates could be obtained by combining pharmacophores containing two or more known drugs or leading compounds. Based on these studies, the new drug research and development could be greatly shortened. This study reviews the research progress of conjugates with antitumor activity based on Chinese herbal medicine. It is expected to serve as a valuable reference to antitumor drug research and clinical application of traditional Chinese medicine.

Chalcone Derivative CX258 Suppresses Colorectal Cancer via Inhibiting the TOP2A/Wnt/β-Catenin Signaling

The deregulation in the Wnt/β-catenin signaling pathway is associated with many human cancers, particularly colorectal cancer (CRC) and, therefore, represents a promising target for drug development. We have screened over 300 semisynthetic and natural compounds using a Wnt reporter assay and identified a family of novel chalcone derivatives (CXs) that inhibited Wnt signaling and CRC cell proliferation. Among them, we selected CX258 for further in vitro and in vivo study to investigate the molecular mechanisms. We found that CX258 significantly inhibited β-catenin expression and nuclear translocation, inducing cell cycle arrest at the G2/M phase in CRC cells. Additionally, CX258 reduced the expression of DNA Topoisomerase II alpha (TOP2A) in CRC cells. Moreover, knocking down TOP2A by siRNAs inhibited the Wnt/β-catenin signaling pathway, a finding suggesting that CX258 inhibited Wnt/β-catenin signaling and CRC cell proliferation at least partially by modulating TOP2A. Further studies showed that CDK1 that interacts with TOP2A was significantly reduced after TOP2A knockdown. We demonstrated that CX258 significantly inhibited DLD-1 CRC cell xenografts in SCID mice. In summary, we identified CX258 as a promising candidate for colorectal cancer treatment by targeting the TOP2A/Wnt/β-catenin signaling pathway.

Antifungal evaluation of quinoline-chalcone derivatives combined with FLC against drug-resistant Candida albicans

With the widespread clinical use of FLC, the FLC-resistant C. albicans greatly increases the difficulty of treatment, and drug combination becomes an important method to treat C. albicans infection. In this work, we have prepared a series of quinoline-chalcone derivatives in good yields, and in vitro antifungal activity against C. albicans were evaluated. The results indicated that most title compounds combined with FLC showed good antifungal activity against drug-resistant C. albicans. Further mechanism researches demonstrated that 6a and 6c combined with FLC could significantly inhibited growth and biofilm formation of C. albicans, induce ROS accumulation, impair the mitochondrial membrane, and decrease intracellular ATP concentrations.

Discovery and biological evaluation of 4,6-pyrimidine analogues with potential anticancer agents as novel colchicine binding site inhibitors

Novel 4,6-pyrimidine analogues were designed and synthesized as colchicine binding site inhibitors (CBSIs) with potent antiproliferative activities. Among them, compound 17j has the most potent activities against 6 human cancer cell lines with IC₅₀ values from 1.1 nM to 4.4 nM, which was 76 times higher than the lead compound 3 in A549 cells. The co-crystal structure of 17j in complex with tubulin confirms the key binding mode at the colchicine binding site. Moreover, 17j inhibited the tubulin polymerization in biochemical assays, depolymerized cellular microtubules, induced the G2/M arrest, inhibited the cell migration, and promoted the initiation of apoptosis. In vivo, 17j effectively inhibits primary tumor growth with tumor growth inhibition rates of 42.51% (5 mg/kg) and 65.42% (10 mg/kg) in A549 xenograft model. Taken together, 17j represents a promising new generation of CBSIs.

Chalcones: Promising therapeutic agents targeting key players and signaling pathways regulating the hallmarks of cancer

The need for innovative anticancer treatments with high effectiveness and low toxicity is urgent due to the development of malignancies that are resistant to chemotherapeutic agents and the poor specificity of existing anticancer treatments. Chalcones are 1,3-diaryl-2-propen-1-ones, which are the precursors for flavonoids and isoflavonoids. Chalcones are readily available from a wide range of natural resources and consist of very basic chemical scaffolds. Because the ease with which the synthesis it allows for the production of several chalcone derivatives. Various in-vitro and in-vivo studies indicate that naturally occurring and synthetic chalcone derivatives exhibit promising biological activities against cancer hallmarks such as proliferation, angiogenesis, invasion, metastasis, inflammation, stemness, and regulation of cancer epigenetics. According to their structure and functional groups, chalcones derivatives and their hybrid compounds exert a broad range of biological activities through targeting key elements and signaling molecules relevant to cancer progression. This review will provide valuable insights into the latest updates of chalcone groups as anticancer agents and extensively discuss their underlying molecular mechanisms of action.

An update on the recent advances and discovery of novel tubulin colchicine binding inhibitors

Microtubules, formed by α- and β-tubulin heterodimer, are considered as a major target to prevent the proliferation of tumor cells. Microtubule-targeted agents have become increasingly effective anticancer drugs. However, due to the relatively sophisticated chemical structure of taxane and vinblastine, their application has faced numerous obstacles. Conversely, the structure of colchicine binding site inhibitors (CBSIs) is much easier to be modified. Moreover, CBSIs have strong antiproliferative effect on multidrug-resistant tumor cells and have become the mainstream research orientation of microtubule-targeted agents. This review focuses mainly on the recent advances of CBSIs during 2017-2022, attempts to depict their biological activities to analyze the structure-activity relationships and offers new perspectives for designing next generation of novel CBSIs.

Quinoline Derivatives with Different Functional Groups: Evaluation of Their Catecholase Activity

In this work, we are interested in finding new catalysts for catecholase, whose principle is based on the oxidation reaction of catechol to o-quinone. In this context, we have studied a series of seven quinoline-based compounds. The present work indicates that the complexes formed between seven selected quinoline compounds and the copper salts viz. Cu(OAc)2, CuSO4, Cu(NO3)2, and CuCl2 elicit catalytic activities for the oxidation of catechol to o-quinone. The complexes formed with the Cu(OAc)2 salt show a much higher catalytic activity than the others, whereas the Cu(NO3)2 and CuCl2 salts formed complexes with low catalytic activity. This study also shows that the oxidation rate depends on two factors, namely the chemical structure of the ligands and the nature of the ions coordinated with the copper.

[1,2,4] Triazolo [3,4-a]isoquinoline chalcone derivative exhibits anticancer activity via induction of oxidative stress, DNA damage, and apoptosis in Ehrlich solid carcinoma-bearing mice

Despite the advances made in cancer therapeutics, their adverse effects remain a major concern, putting safer therapeutic options in high demand. Since chalcones, a group of flavonoids and isoflavonoids, act as promising anticancer agents, we aimed to evaluate the in vivo anticancer activity of a synthetic isoquinoline chalcone (CHE) in a mice model with Ehrlich solid carcinoma. Our in vivo pilot experiments revealed that the maximum tolerated body weight-adjusted CHE dose was 428 mg/kg. Female BALB/c mice were inoculated with Ehrlich ascites carcinoma cells and randomly assigned to three different CHE doses administered intraperitoneally (IP; 107, 214, and 321 mg/kg) twice a week for two consecutive weeks. A group injected with doxorubicin (DOX; 4 mg/kg IP) was used as a positive control. We found that in CHE-treated groups: (1) tumor weight was significantly decreased; (2) the total antioxidant concentration was substantially depleted in tumor tissues, resulting in elevated oxidative stress and DNA damage evidenced through DNA fragmentation and comet assays; (3) pro-apoptotic genes p53 and Bax, assessed via qPCR, were significantly upregulated. Interestingly, CHE treatment reduced immunohistochemical staining of the proliferative marker ki67, whereas BAX was increased. Notably, histopathological examination indicated that unlike DOX, CHE treatment had minimal toxicity on the liver and kidney. In conclusion, CHE exerts antitumor activity via induction of oxidative stress and DNA damage that lead to apoptosis, making CHE a promising candidate for solid tumor therapy.

A Novel L-Phenylalanine Dipeptide Inhibits the Growth and Metastasis of Prostate Cancer Cells via Targeting DUSP1 and TNFSF9

Prostate cancer (PCa) is a common malignant cancer of the urinary system. Drug therapy, chemotherapy, and radical prostatectomy are the primary treatment methods, but drug resistance and postoperative recurrence often occur. Therefore, seeking novel anti-tumor compounds with high efficiency and low toxicity from natural products can produce a new tumor treatment method. Matijin-Su [N-(N-benzoyl-L-phenylalanyl)-O-acetyl-L-phenylalanol, MTS] is a phenylalanine dipeptide monomer compound that is isolated from the Chinese ethnic medicine Matijin (Dichondra repens Forst.). Its derivatives exhibit various pharmacological activities, especially anti-tumor. Among them, the novel MTS derivative HXL131 has a significant inhibitory effect against prostate tumor growth and metastasis. This study is designed to investigate the effects of HXL131 on the growth and metastasis of human PCa cell lines PC3 and its molecular mechanism through in vitro experiments combined with proteomics, molecular docking, and gene silencing. The in vitro results showed that HXL131 concentration dependently inhibited PC3 cell proliferation, induced apoptosis, arrested cell cycle at the G2/M phase, and inhibited cell migration capacity. A proteomic analysis and a Western blot showed that HXL131 up-regulated the expression of proliferation, apoptosis, cell cycle, and migration-related proteins CYR61, TIMP1, SOD2, IL6, SERPINE2, DUSP1, TNFSF9, OSMR, TNFRSF10D, and TNFRSF12A. Molecular docking, a cellular thermal shift assay (CETSA), and gene silencing showed that HXL131 had a strong binding affinity with DUSP1 and TNFSF9, which are important target genes for inhibiting the growth and metastasis of PC3 cells. This study demonstrates that HXL131 exhibited excellent anti-prostate cancer activity and inhibited the growth and metastasis of prostate cancer cells by regulating the expression of DUSP1 and TNFSF9.

Discovery of a Novel Vascular Disrupting Agent Inhibiting Tubulin Polymerization and HDACs with Potent Antitumor Effects

Most vascular disrupting agents (VDAs) fail to prevent the regrowth of blood vessels at the edge of tumors, causing tumor rebound and relapse. Herein, a series of novel multifunctional vascular disrupting agents (VDAs) capable of inhibiting microtubule polymerization and histone deacetylases (HDACs) were designed and synthesized using the tubulin polymerization inhibitor TH-0 as the lead compound. Among them, compound TH-6 exhibited the most potent antiproliferative activity (IC₅₀ = 18-30 nM) against a panel of cancer cell lines. As expected, TH-6 inhibited tubulin assembly and increased the acetylation level of HDAC substrate proteins in HepG2 cells. Further in vivo antitumor assay displayed that TH-6 effectively inhibited tumor growth with no apparent toxicity. More importantly, TH-6 disrupted both the internal and peripheral tumor vasculatures, which contributed to the persistent tumor inhibitory effects after drug withdrawal. Altogether, TH-6 deserves to be further investigated for the new approach to clinical cancer therapy.

Discovery of Novel Benzo[4,5]imidazo[1,2-a]pyrazin-1-amine-3-amide-one Derivatives as Anticancer Human A2A Adenosine Receptor Antagonists

The blockade of A_2A adenosine receptor (A_2AAR) activates immunostimulatory response through regulating signaling in tumor microenvironment. Thus, A_2AAR has been proposed as a promising target for cancer immunotherapy. In this work, we designed a new series of benzo[4,5]imidazo[1,2-a]pyrazin-1-amine derivatives bearing an amide substitution at 3-position to obtain potent antitumor antagonist in vivo. The structure-activity relationship studies were performed by molecular modeling and radioactive assay. The in vitro anticancer activities were evaluated by 3',5'-cyclic adenosine monophosphate (cAMP) functional and T cell activation assay. The most potent compound 12o·2HCl showed much higher affinity toward A_2AAR (K_i = 0.08 nM) and exhibited more significant in vitro immunostimulatory anticancer activity than clinical antagonist AZD4635. More importantly, 12o·2HCl significantly inhibited the growth of triple-negative breast cancer by reversing immunosuppressive tumor microenvironment in the xenograft mouse model without severe toxicity at the testing dose. These results make 12o·2HCl a promising immunotherapy anticancer drug candidate.

Synthesis and Antiproliferative Activity of Novel Dehydroabietic Acid-Chalcone Hybrids

Dehydroabietic Acid (DHA, 1) derivatives are known for their antiproliferative properties, among others. In the context of this work, DHA was initially modified to two key intermediates bearing a C18 methyl ester, a phenol moiety at C12, and an acetyl or formyl group at C13 position. These derivatives allowed us to synthesize a series of DHA-chalcone hybrids, suitable for structure–activity relationship studies (SARS), following their condensation with a variety of aryl-aldehydes and methyl ketones. The antiproliferative evaluation of the synthesized DHA-chalcone hybrids against three breast cancer cell lines (the estrogen-dependent MCF-7 and the estrogen-independent MDA-MB-231 and Hs578T) showed that eight derivatives (33, 35, 37, 38, 39, 41, 43, 44) exhibit low micromolar activity levels (IC₅₀ 2.21–11.5 μΜ/MCF-7). For instance, some of them showed better activity compared to the commercial anticancer drug 5-FU against MCF-7 cells (33, 41, 43, 44) and against MDA-MB231 (33 and 41). Hybrid 38 is a promising lead compound for the treatment of MCF-7 breast cancer, exhibiting comparable activity to 5-FU and being 12.9 times less toxic (SI = 22.7). Thus, our findings suggest that DHA-chalcone hybrids are drug candidates worth pursuing for further development in the search for novel breast cancer therapies.

A new quinolinone-chalcone hybrid with potential antibacterial and herbicidal properties using in silico approaches

Quinolinone-chalcones are hybrid compounds consisting of chalcone and quinolone moieties with biological activity related to their hybrid structure. This work seeks to describe the structural and theoretical parameters related to the physicochemical properties and biological activity of a new quinolinone-chalcone. The synthesis, structural characterization by X-ray diffraction, molecular topology by Hirshfeld surfaces and QTAIM, molecular electronic calculations, and pharmacophore analysis were described. The weak interactions C-H^…O, C-H^…π, and C-H^…Br were responsible for crystal growth and stabilized the crystalline state. The DFT analysis shows that the sulfonamide group region is susceptible to observed interactions, and the frontier molecular orbitals indicate high kinetic stability. Also, pharmacophore analysis revealed potential antibacterial and herbicidal activity; by docking within the active site of TtgR, a transcription regulator for the efflux pump TtgABC from the highly resistant Pseudomonas putida (P. putida) strain DOT-TIE, we showed that the activation of TtgR relies upon the binding of aromatic-harboring compounds, which plays a crucial role in bacterial evasion. In this context, a new quinolinone-chalcone has a higher binding affinity than tetracycline, which suggests it might be a better effector for TtgR.

Novel chloroquine derivative suppresses melanoma cell growth by DNA damage through increasing ROS levels

Melanoma is a fatal cancer with a significant feature of resistance to traditional chemotherapeutic drugs and radiotherapy. A mutation in the kinase BRAF is observed in more than 66% of metastatic melanoma cases. Therefore, there is an urgent need to develop new BRAF-mutant melanoma inhibitors. High-dose chloroquine has been reported to have antitumour effects, but it often induces dose-limiting toxicity. In this study, a series of chloroquine derivatives were synthesized, and lj-2-66 had the best activity and was selected for further investigation. Furthermore, the anti-BRAF-mutant melanoma effect and mechanism of this compound were explored. CCK-8 and colony formation assays indicated that lj-2-66 significantly inhibited the proliferation of BRAF-mutant melanoma cells. Flow cytometry revealed that lj-2-66 induced G2/M arrest in melanoma cells and promoted apoptosis. Furthermore, lj-2-66 increased the level of ROS in melanoma cells and induced DNA damage. Interestingly, lj-2-66 also played a similar role in BRAF inhibitor-resistant melanoma cells. In summary, we found a novel chloroquine derivative, lj-2-66, that increased the level of ROS in melanoma cells and induced DNA damage, thus leading to G2/M arrest and apoptosis. These findings indicated that lj-2-66 may become a potential therapeutic drug for melanoma harbouring BRAF mutations.

Evaluation of 2-Thioxoimadazolidin-4-one Derivatives as Potent Anti-Cancer Agents through Apoptosis Induction and Antioxidant Activation: In Vitro and In Vivo Approaches

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most widespread malignancies and is reported as the fourth most prevalent cause of cancer deaths worldwide. Therefore, we aimed to investigate the probable mechanistic cytotoxic effect of the promising 2-thioxoimidazolidin-4-one derivative on liver cancer cells using in vitro and in vivo approaches. The compounds were tested for the in vitro cytotoxic activity using MTT assay, and the promising compound was tested in colony forming unit assay, flow cytometric analysis, RT-PCR, Western blotting, in vivo using SEC-carcinoma and in silico to highlight the virtual mechanism of action. Both compounds 4 and 2 performed cytotoxic effects against HepG2 cells with IC50 values of 0.017 and 0.18 μM, respectively, compared to Staurosporine and 5-Fu as reference drugs with IC50 values of 5.07 and 5.18 µM, respectively. Compound 4 treatment revealed apoptosis induction by 19.35-fold (11.42% compared to 0.59% in control), arresting the cell cycle at G2/M phase. Moreover, studying gene expression that plays critical roles in cell cycle and apoptosis by RT-PCR demonstrated that compound 4 enhances the expression of the pro-apoptotic genes p53, PUMA, and Caspase 3, 8, and 9, and impedes the anti-apoptotic Bcl-2 gene in the HepG2 cells. It can also inhibit the PI3K/AKT pathway at both gene and protein levels, which was reinforced by the in silico predictions of the molecular docking simulations towards the PI3K/AKT proteins. Finally, in vivo study verified that compound 4 has a promising anti-cancer activity through activating antioxidant levels (CAT, SOD and GSH) and ameliorating hematological, biochemical, and histopathological findings.

Recent contributions of quinolines to antimalarial and anticancer drug discovery research

Quinoline, a privileged scaffold in medicinal chemistry, has always been associated with a multitude of biological activities. Especially in antimalarial and anticancer research, quinoline played (and still plays) a central role, giving rise to the development of an array of quinoline-containing pharmaceuticals in these therapeutic areas. However, both diseases still affect millions of people every year, pointing to the necessity of new therapies. Quinolines have a long-standing history as antimalarial agents, but established quinoline-containing antimalarial drugs are now facing widespread resistance of the Plasmodium parasite. Nevertheless, as evidenced by a massive number of recent literature contributions, they are still of great value for future developments in this field. On the other hand, the number of currently approved anticancer drugs containing a quinoline scaffold are limited, but a strong increase and interest in quinoline compounds as potential anticancer agents can be seen in the last few years. In this review, a literature overview of recent contributions made by quinoline-containing compounds as potent antimalarial or anticancer agents is provided, covering publications between 2018 and 2020.

A review on synthetic chalcone derivatives as tubulin polymerisation inhibitors

Microtubules play an important role in the process of cell mitosis and can form a spindle in the mitotic prophase of the cell, which can pull chromosomes to the ends of the cell and then divide into two daughter cells to complete the process of mitosis. Tubulin inhibitors suppress cell proliferation by inhibiting microtubule dynamics and disrupting microtubule homeostasis. Thereby inducing a cell cycle arrest at the G2/M phase and interfering with the mitotic process. It has been found that a variety of chalcone derivatives can bind to microtubule proteins and disrupt the dynamic balance of microtubules, inhibit the proliferation of tumour cells, and exert anti-tumour effects. Consequently, a great number of studies have been conducted on chalcone derivatives targeting microtubule proteins. In this review, synthetic or natural chalcone microtubule inhibitors in recent years are described, along with their structure-activity relationship (SAR) for anticancer activity.

Synthesis and Evaluation of Novel Quinazolinone Derivatives as Potential Anti-HCC Agents

Hepatocellular carcinoma (HCC), a common malignancy worldwide, has a high mortality rate and limited effective therapeutic options. In this work, a series of quinazolinone compounds (6a-t and 7a-i) were synthesized as potential anti-HCC agents. Among them, compound 7b more potently inhibited HepG2, HUH7 and SK-Hep-1 cells proliferation than classical anti-HCC drug sorafenib, indicating its potential anti-HCC effect. Interestingly, 7b could dose-dependently decrease Cyclin D1 and CDK2 levels, and increase p21 protein expression, thus inducing HepG2 cells cycle arrest at G0/G1 phase. In addition, 7b also displayed potent apoptosis-induced effect on HepG2 cells by interfering Bad, Bax, Bcl-2 and Bcl-xl proteins expression. Notably, 7b could efficiently block the activity of PI3K pathway by dose-dependently reducing the phosphorylation of PI3K (Y607) and AKT (S473). Moreover, predicted ADME properties indicated that 7b possessed a good pharmacokinetic profile. Collectively, compound 7b might be a promising lead to the development of novel therapeutic agents towards HCC.

Discovery of novel quinoline-based analogues of combretastatin A-4 as tubulin polymerisation inhibitors with apoptosis inducing activity and potent anticancer effect

A new series of quinoline derivatives of combretastatin A-4 have been designed, synthesised and demonstrated as tubulin polymerisation inhibitors. These novel compounds showed significant antiproliferative activities, among them, 12c exhibited the most potent inhibitory activity against different cancer cell lines (MCF-7, HL-60, HCT-116 and HeLa) with IC50 ranging from 0.010 to 0.042 µM, and with selectivity profile against MCF-10A non-cancer cells. Further mechanistic studies suggest that 12c can inhibit tubulin polymerisation and cell migration, leading to G2/M phase arrest. Besides, 12c induces apoptosis via a mitochondrial-dependant apoptosis pathway and caused reactive oxygen stress generation in MCF-7 cells. These results provide guidance for further rational development of potent tubulin polymerisation inhibitors for the treatment of cancer.HighlightsA novel series of quinoline derivatives of combretastatin A-4 have been designed and synthesised.Compound 12c showed significant antiproliferative activities against different cancer cell lines.Compound 12c effectively inhibited tubulin polymerisation and competed with [3H] colchicine in binding to tubulin.Compound 12c arrested the cell cycle at G2/M phase, effectively inducing apoptosis and inhibition of cell migration.

Design, synthesis and bioactivity evaluation of novel evodiamine derivatives with excellent potency against gastric cancer

Gastric cancer represents a significant health burden worldwide. Previously, inspired by the traditional Chinese medicine Wu-Chu-Yu to treat the spleen and stomach system for thousands of years, we identified N14-phenyl substituted evodiamine derivatives as potential antitumor agents with favorable inhibition on Top1. Herein, structural optimization and structure-activity relationship studies (SARs) led us to discovering a highly active evodiamine derivative compound 6t against gastric cancer. Further anti-tumor mechanism studies revealed that compound 6t played as the inhibition of topoisomerase 1 (Top1), effectively induced apoptosis, obviously arrested the cell cycle at the G2/M phase, and significantly inhibited the migration and invasion of SGC-7901 and MGC-803 cell lines in a dose-dependent manner. Moreover, the compound 6t was low toxicity in vivo and exhibited excellent anti-tumor activity (TGI = 70.12%) in the MGC-803 xenograft models. In summary, compound 6t represents a promising candidate as a potential chemotherapeutic agent against gastric cancer.

Design, Synthesis and Bioactivity Evaluation of Novel Chalcone Derivatives Possessing Tryptophan Moiety with Dual Activities of Anti-cancer and Partially Restoring the Proliferation of Normal Kidney Cells Pre-treated with Cisplatin

BACKGROUND

Chalcone is a broad-spectrum natural product with anti-cancer and anti-inflammatory activities. However, low potency, low selectivity, and serious side effects limit its druggability. L-Tryptophan is an essential precursor molecule of an anti-cancer active substance. Also, the indole moiety inhibits the proliferation of tumor cells by binding to colchicine sites. A decrease in kidney cell activity caused by kidney inflammation is the primary side effect of cancer therapy.

OBJECTIVE

The purpose of this work was to design, synthesize, and perform bioactivity evaluation of novel chalcone derivatives possessing tryptophan moiety with dual activities of anti-cancer and partially restoring the proliferation of normal kidney cells pre-treated with cisplatin.

METHODS

A series of novel chalcone derivatives possessing tryptophan moiety (5a-5g, 6a-6o) were designed, synthesized, and evaluated for anti-cancer activity against four cancer cell lines (gastric (HGC-27), colon (HCT-116), prostate (PC-3), and lung (A549)), and a human normal cell line (gastric mucosal epithelial (GES-1)). The activity of restoring the proliferation of normal kidney cells pre-treated with cisplatin was evaluated by MTT assay. Cell cycle, apoptosis, and apoptosis proteins (Bax and Bcl-2) were used to evaluate the anti-cancer mechanism of the most potent compound. Moreover, a docking study was performed to explain the high anti-cancer activity of 6n. The expressions of TNF-α, IL-6, and MCP-1 were detected by ELISA.

RESULTS

Most of the compounds exhibited high anti-cancer activity against the HGC-27 cell line and exhibited low toxicity against the normal cell line. Based on three rounds of a structure optimization, 6n was discovered as the most potent compound against HGC-27 cells with an IC50 value of 2.02 μM and an SI value of 28.47. Further studies demonstrated that 6n could induce cell cycle arrest at the G2/M phase and the apoptosis of the HGC-27 cell line by reducing the expression of Bcl-2 and improving the expression level of Bax. Molecular docking result displayed 6n bound to the colchicine site. At the same time, 6n also exhibited moderate activity of restoring the proliferation of normal kidney cells pre-treated with cisplatin by reducing the expression of inflammatory substances.

CONCLUSION

Our findings collectively suggested that 6n should be further studied as a potential anti-cancer agent that could partially restore the proliferation of normal kidney cells pre-treated with cisplatin in gastric cancer patients by an anti-inflammatory pathway.

Anticancer Activity of Natural and Synthetic Chalcones

Cancer is a condition caused by many mechanisms (genetic, immune, oxidation, and inflammatory). Anticancer therapy aims to destroy or stop the growth of cancer cells. Resistance to treatment is theleading cause of the inefficiency of current standard therapies. Targeted therapies are the most effective due to the low number of side effects and low resistance. Among the small molecule natural compounds, flavonoids are of particular interest for theidentification of new anticancer agents. Chalcones are precursors to all flavonoids and have many biological activities. The anticancer activity of chalcones is due to the ability of these compounds to act on many targets. Natural chalcones, such as licochalcones, xanthohumol (XN), panduretin (PA), and loncocarpine, have been extensively studied and modulated. Modification of the basic structure of chalcones in order to obtain compounds with superior cytotoxic properties has been performed by modulating the aromatic residues, replacing aromatic residues with heterocycles, and obtaining hybrid molecules. A huge number of chalcone derivatives with residues such as diaryl ether, sulfonamide, and amine have been obtained, their presence being favorable for anticancer activity. Modification of the amino group in the structure of aminochalconesis always favorable for antitumor activity. This is why hybrid molecules of chalcones with different nitrogen hetercycles in the molecule have been obtained. From these, azoles (imidazole, oxazoles, tetrazoles, thiazoles, 1,2,3-triazoles, and 1,2,4-triazoles) are of particular importance for the identification of new anticancer agents.

Identification and optimization of biphenyl derivatives as novel tubulin inhibitors targeting colchicine-binding site overcoming multidrug resistance

Microtubule targeting agents (MTAs) are among the most successful chemotherapeutic drugs, but their efficacy is often limited by the development of multidrug resistance (MDR). Therefore, the development of novel MTAs with the ability to overcome MDR is urgently needed. In this contribution, through modification of the unsymmetric biaryl compounds, we discovered a novel compound dxy-1-175 with potent anti-proliferative activity against cancer cells. Mechanistic study revealed that dxy-1-175 inhibited tubulin polymerization by interacting with the colchicine-binding site of tubulin, which caused cell cycle arrest at G₂/M phase. Based on the predicted binding model of dxy-1-175 with tubulin, a series of new 4-benzoylbiphenyl analogues were designed and synthesized. Among them, the hydrochloride compound 12e with improved solubility and good stability in human liver microsome, exhibited the most potent anti-proliferative activity with IC₅₀ value in the low nanomolar range, and markedly inhibited the growth of breast cancer 4T1 xenograft in vivo. Notably, 12e effectively overcame P-gp-mediated MDR and our preliminary data suggested that 12e may not be a substrate of P-glycoprotein (P-gp). Taken together, our study reveals a novel MTA 12e targeting the colchicine-binding site with potent anticancer activity and the ability to circumvent MDR.

Synthesis, delivery, and molecular docking of fused quinolines as inhibitor of Hepatitis A virus 3C proteinase

It is widely accepted that Hepatitis A virus (HAV) is responsible for liver failure and even death in older people and in people with other serious health issues; so, proposing new compounds with inhibitory activity can help to treated of these disease’s. In current study, a new class of quinolines is proposed with inhibitor activity of the HAV proteinase. So, in the first step, fused quinoline derivatives has been synthesized in short reaction time (12.0 min) and high efficiency yields (94%) in presence of 1-carboxymethyl-2,3-dimethylimidazolium iodide ([cmdmim]I) ionic liquid catalyst using a new method. In the following, chemical reactivity and inhibitory activity of synthesized quinolines were evaluated in density functional theory (DFT) framework and molecular docking methodologies. High global softness (0.67 eV), low HOMO_SWBNNT-LUMO_4a gap (4.78 eV), and more negative adsorption energy (− 87.9 kJ mol⁻¹) in these quinolines reveal that the 4a and 4b compounds have better delivery than other quinolines using SWBNNT as suitable carrier to target cells. Molecular docking shows that the best cavity of the HAV has − 134.2 kJ mol⁻¹ interaction energy involving bonding and non-bonding interactions. In fact, these interactions are between fused quinolines with especial geometries and sidechain flexibility amino acids residues inside the best binding site of the HAV, as hydrogen bonding, steric, and electrostatic interactions. So, these interactions imply that proposed fused quinolines have good inhibitor activity for the HAV.

Design, Synthesis, and Anticancer Activity Studies of Novel Quinoline-Chalcone Derivatives

The chalcone and quinoline scaffolds are frequently utilized to design novel anticancer agents. As the continuation of our work on effective anticancer agents, we assumed that linking chalcone fragment to the quinoline scaffold through the principle of molecular hybridization strategy could produce novel compounds with potential anticancer activity. Therefore, quinoline-chalcone derivatives were designed and synthesized, and we explored their antiproliferative activity against MGC-803, HCT-116, and MCF-7 cells. Among these compounds, compound 12e exhibited a most excellent inhibitory potency against MGC-803, HCT-116, and MCF-7 cells with IC50 values of 1.38, 5.34, and 5.21 µM, respectively. The structure-activity relationship of quinoline-chalcone derivatives was preliminarily explored in this report. Further mechanism studies suggested that compound 12e inhibited MGC-803 cells in a dose-dependent manner and the cell colony formation activity of MGC-803 cells, arrested MGC-803 cells at the G2/M phase and significantly upregulated the levels of apoptosis-related proteins (Caspase3/9 and cleaved-PARP) in MGC-803 cells. In addition, compound 12e could significantly induce ROS generation, and was dependent on ROS production to exert inhibitory effects on gastric cancer cells. Taken together, all the results suggested that directly linking chalcone fragment to the quinoline scaffold could produce novel anticancer molecules, and compound 12e might be a valuable lead compound for the development of anticancer agents.

Design, synthesis and biological evaluation of indole-based [1,2,4]triazolo[4,3-a] pyridine derivatives as novel microtubule polymerization inhibitors

A series of indole-based [1,2,4]triazolo [4,3-a]pyridine derivatives was designed and synthesized as novel microtubulin polymerization inhibitors by using a conformational restriction strategy. These compounds exhibited moderate to potent anti-proliferative activities against a panel of cancer cell lines (HeLa, A549, MCF-7 and HCT116). Among them, compound 12d featuring a N-methyl-5-indolyl substituent at the C-6 position of the [1,2,4]triazolo [4,3-a]pyridine core exhibited the highest antiproliferative activity with the IC₅₀ values ranging from 15 to 69 nM, and remarkable inhibitory effect on tubulin polymerization with an IC₅₀ value of 1.64 μM. Mechanistic studies revealed that compound 12d induced cellular apoptosis and cell cycle arrest at the G₂/M phase in a dose-dependent fashion. Moreover, compound 12d significantly suppressed wound closure and disturbed microtubule networks.

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.

Bifunctional chiral selenium-containing 1,4-diarylazetidin-2-ones with potent antitumor activities by disrupting tubulin polymerization and inducing reactive oxygen species production

Organoselenium compounds have attracted growing interests as promising antitumor agents over recent years. Herein, four series of novel selenium-containing chiral 1,4-diarylazetidin-2-ones were asymmetrically synthesized and biologically evaluated for antitumor activities. Among them, compound 7 was found to be about 10-fold more potent than its prototype compound 1a, and compound 9a exhibited the most potent cytotoxicity against five human cancer cell lines, including a paclitaxel-resistant human ovarian cancer cell line A2780T, with IC₅₀ values ranging from 1 to 3 nM. Mechanistic studies revealed that compound 9a worked by disrupting tubulin polymerization, inducing reactive oxygen species (ROS) production, decreasing mitochondrial membrane potential, blocking the cell cycle in the G₂/M phase, inducing cellular apoptosis and suppressing angiogenesis. Additionally, compound 9a exhibited appropriate human-microsomal metabolic stability and physicochemical properties. Importantly, compound 9a was found to inhibit tumor growth effectively in a xenograft mice model with low toxicity profile, which rendered 9a a highly promising candidate for further pre-clinical development.

Tubulin Inhibitors: A Chemoinformatic Analysis Using Cell-Based Data

Inhibiting the tubulin-microtubules (Tub-Mts) system is a classic and rational approach for treating different types of cancers. A large amount of data on inhibitors in the clinic supports Tub-Mts as a validated target. However, most of the inhibitors reported thus far have been developed around common chemical scaffolds covering a narrow region of the chemical space with limited innovation. This manuscript aims to discuss the first activity landscape and scaffold content analysis of an assembled and curated cell-based database of 851 Tub-Mts inhibitors with reported activity against five cancer cell lines and the Tub-Mts system. The structure-bioactivity relationships of the Tub-Mts system inhibitors were further explored using constellations plots. This recently developed methodology enables the rapid but quantitative assessment of analog series enriched with active compounds. The constellations plots identified promising analog series with high average biological activity that could be the starting points of new and more potent Tub-Mts inhibitors.