Exploration of quinolone and quinoline derivatives as potential anticancer agents

An insight into sustainable and green chemistry approaches for the synthesis of quinoline derivatives as anticancer agents

Quinolones, a key class of heterocyclics, are gaining popularity among organic and medicinal chemists due to their promising properties. Quinoline, with its broad spectrum of action, plays a primordial role in chemotherapy for cancer. Drugs include lenvatinib and its structural derivatives carbozantinib and bosutinib, and tipifarnib are the popular anticancer agents. Owing to the importance of quinoline, there are several classical methods for the synthesis such as, such as Gould-Jacobs, Conrad-Limpach, Camps cyclization, Skraup, Doebnervon Miller, Combes, Friedlander, Pfitzinger, and Niementowski synthesis. These methods are well-commended for developing an infinite variety of quinoline analogues. However, these procedures are associated with several drawbacks such as long reaction times, use of hazardous chemicals or stoichiometric proportions, difficulty of working up conditions, high temperatures, organic solvents, and the presence of numerous steps, all of which have an impact on the environment and the economy. As a result, researchers are working hard to develop green quinoline compounds in the hopes of making groundbreaking discoveries in the realm of cancer. In this review, we have highlighted significant research on quinoline-based compounds and their structure-activity relationship (SAR). Furthermore, because of the significant economic and environmental health and safety (EHS) concerns, more research is being dedicated to the green synthesis of quinolone derivatives. The current review offers recent advances in quinoline derivatives as anticancer agents for green synthesis using microwave, ultrasound, and one-pot synthesis. We believe that our findings will provide useful insight and inspire more green research on this framework to produce powerful and selective quinoline derivatives.

Synthesis and biological evaluation of novel 2-morpholino-4-anilinoquinoline derivatives as antitumor agents against HepG2 cell line

Cancer is a life-threatening illness all over the world, and developing anticancer treatments with high efficacy and low side effects remains a challenge. The quinoline ring structure has long been recognized as a flexible nucleus in the design and synthesis of physiologically active chemicals. In this study, five new 2-morpholino-4-anilinoquinoline compounds were synthesized and their biological anticancer potential against the HepG2 cell line was assessed. The compounds produced demonstrated varying responses against HepG2 cells, with compounds 3c, 3d, and 3e exhibiting the highest activity, with IC50 values of 11.42, 8.50, and 12.76 μM, respectively. It is a critical requirement that anticancer medications are able to selectively decrease cancer growth while not causing damage to normal cells. Compound 3e exhibited increased activity while maintaining adequate selectivity. It was also the most effective chemical against cell migration and adhesion, which could play an important role in drug resistance and cell metastasis. In total, the findings revealed good possibilities for anticancer therapy, suggesting a target for future development of anticancer medication.

Phytochemistry Profile, Antimicrobial and Antitumor Potential of the Methanolic Extract of Tabernaemontana catharinensis A DC and Eragrostis plana NEES

Natural compounds that have the potential to act as antimicrobials and antitumors are a constant search in the field of pharmacotherapy. Eragrostis plana NEES (Poaceae) is a grass with high allelopathic potential. Allelopathy is associated with compounds generated in the primary and secondary metabolism of the plant, which act to protect it from phytopathogens. Tabernaemontana catharinensis A DC (Apocynaceae), a tree in which its leaves and bark are used for the preparation of extracts and infusions that have anti-inflammatory and antinociceptive effects, is attributed to its phytochemical constitution. The objective of this study was to elucidate the phytochemical constitution, the antibacterial potential, the toxicity against immune system cells, hemolytic potential, and antitumor effect of methanolic extracts of E. plana and T. catharinensis. The phytochemical investigation was carried out using the UHPLC-QTOF MS equipment. The antibacterial activity was tested using the broth microdilution plate assay, against Gram-negative and Gram-positive strains, and cytotoxicity assays were performed on human peripheral blood mononuclear cells (PBMC) and in vitro hemolysis. Antitumor activity was performed against the colon cancer cell line (CT26). Results were expressed as mean and standard deviation and analyzed by ANOVA. p < 0.05 was considered significant. More than 19 possible phytochemical constituents were identified for each plant, with emphasis on phenolic compounds (acids: vanillic, caffeic, and quinic) and alkaloids (alstovenine, rhyncophylline, amezepine, voacangine, and coronaridine). Both extracts showed antibacterial activity at concentrations below 500 µg/mL and were able to decrease the viability of CT26 at concentrations below 2000 µg/mL, without showing cytotoxic effect on PBMCs and in vitro hemolysis at the highest concentration tested. This is the first report of the activity of E. plana and T. catharinensis extracts against colon cancer cell line (CT26). Studies should be carried out to verify possible molecular targets involved in the antitumor effect in vivo.

Quinolone Derivatives as Anticancer Agents: Importance in Medicinal Chemistry

Quinolone is a heterocyclic compound containing carbonyl at the C-2 or C-4 positions with nitrogen at the C-1 position. The scaffold was first identified for its antibacterial properties, and the derivatives were known to possess many pharmacological activities, including anticancer. In this review, the quinolin-2(H)-one and quinolin-4(H)-one derivatives were identified to inhibit several various proteins and enzymes involved in cancer cell growth, such as topoisomerase, microtubules, protein kinases, phosphoinositide 3-kinases (PI3K) and histone deacetylase (HDAC). Hybrids of quinolone with curcumin or chalcone, 2-phenylpyrroloquinolin-4-one and 4-quinolone derivatives have demonstrated strong potency against cancer cell lines. Additionally, quinolones have been explored as inhibitors of protein kinases, including EGFR and VEGFR. Therefore, this review aims to consolidate the medicinal chemistry of quinolone derivatives in the pipeline and discuss their similarities in terms of their pharmacokinetic profiles and potential target sites to provide an understanding of the structural requirements of anticancer quinolones.

Novel amodiaquine analogues to treat cervical cancer and microbial infection in the future

Aim: To synthesize and explore the therapeutic potential of amodiaquine analogues. Methodology: New promising analogues were synthesized by nucleophilic substitution at the 4-amino position and were characterized using 1H NMR, 13C NMR and FT-IR spectroscopic techniques. Results: Antibacterial and cytotoxic screening revealed the high potency of these compounds; analogue AS1 had an 34.3 ± 0.18 mm zone of inhibition against Pseudomonas aeruginosa. Excellent activity against fungal strains, that is, Candida albicans (39.6 ± 0.23 mm) was shown by analogue AS2. Analogue AS1 had an IC50 = 4.2 μg/ml against the HeLa cell line (cervical cancer) and binding energy against 5GWK (-8.32688 kcal/mol), 1PFK (-6.4780 kcal/mol) and 1TUP (-6.5279 kcal/mol) in the docking study. Conclusion: The obtained results reveal that these analogues exhibit potent antimicrobial and cytotoxic potential.

Synthesis, Antioxidant and Antiproliferative Actions of 4-(1,2,3-Triazol-1-yl)quinolin-2(1H)-ones as Multi-Target Inhibitors

The reaction of 4-azido-quinolin-2(1H)-ones 1a-e with the active methylene compounds pentane-2,4-dione (2a), 1,3-diphenylpropane-1,3-dione (2b), and K2CO3 was investigated in this study. This approach afforded 4-(1,2,3-triazol-1-yl)quinolin-2(1H)-ones 3a-j in high yields and purity. All newly synthesized products' structures were identified. Compounds 3a-j were tested for antiproliferative activity against a panel of four cancer cell lines. In comparison to the reference erlotinib (GI50 = 33), compounds 3f-j were the most potent derivatives, with GI50 values ranging from 22 nM to 31 nM. The most effective antiproliferative derivatives, 3f-j, were subsequently investigated as possible multi-target inhibitors of EGFR, BRAFV600E, and EGFRT790M. Compound 3h was the most potent inhibitor of the studied molecular targets, with IC50 values of 57 nM, 68 nM, and 9.70 nM, respectively. The apoptotic assay results demonstrated that compounds 3g and 3h function as caspase-3, 8, and Bax activators as well as down-regulators of the antiapoptotic Bcl2, and hence can be classified as apoptotic inducers. Finally, compounds 3g and 3h displayed promising antioxidant activity at 10 µM, with DPPH radical scavenging of 70.6% and 73.5%, respectively, compared to Trolox (77.6%).

Synthesis of Quinoline-2-Carboxylic Acid Aryl Ester and Its Apoptotic Action on PC3 Prostate Cancer Cell Line

The aim of the present study is to synthesise an aryl ester compound from quinoline-2-carboxylic acid to evaluate its apoptotic, cell cycle blockade, and antiproliferative activity on the prostate cancer cell lines (PC3). Chromatographic and spectroscopic analysis was used to identify the synthesised carboxylic acid compound. The synthesised compound was treated with a PC3 cell line for 24 h with control. The cells were treated at various concentration ranges of 0, 3.91, 7.81, 15.63, 31.25, 62.5, 125, 250, 500, and 1000 µg/mL each. The cytotoxicity effect was studied by MTT assay, and their anticancer activity was further evaluated using cell cycle analysis, DNA fragmentation assay, acridine orange-ethidium bromide staining, and Western blot analysis. The end antiproliferative result showed that PC3 cell viability decreases in a concentration-dependent manner and the synthesised compound exhibited potent cytotoxicity against PC3 cells with an IC50 value of 26 µg/mL at the concentration of 125 µg. The increase in the number of apoptotic cells was observed after treating PC3 cells with the sample in double-staining methods. S phase of the cell cycle was significantly blocked by the test sample, and a typical ladder pattern of internucleosomal fragmentation was observed. A decrease in the live cells was observed with the sample in AO/ET-BR. A significant increase in the Bax expression and a decrease in Bcl-2 expression observed enhance the activity of caspases-7 and -9. The synthesised compound had shown to possess excellent cytotoxic effect through inducing apoptosis, especially causing cell cycle arrest at the S phase.

Developing our knowledge of the quinolone scaffold and its value to anticancer drug design

INTRODUCTION

The quinolone scaffold is a bicyclic benzene-pyridinic ring scaffold with nitrogen at the first position and a carbonyl group at the second or fourth position. It is endowed with a diverse spectrum of pharmacological activities, including antitumor activity, and has progressed into various development phases of clinical trials for their target-specific anticancer activity.

AREAS COVERED

The present review covers both classes of quinolones, i.e. quinolin-2(H)-one and quinolin-4(H)-one as anticancer agents, along with their possible mode of binding. Furthermore, their structure-activity relationships, molecular mechanisms, and pharmacokinetic properties are also covered to provide insight into their structural requirements for their rational design as anticancer agents.

EXPERT OPINION

Synthetic feasibility and ease of derivatization at multiple positions, has allowed medicinal chemists to explore quinolones and their chemical diversity to discover newer anticancer agents. The presence of both hydrogen bond donor (-NH) and acceptor (-C=O) functionality in the basic scaffold at two different positions, has broadened the research scope. In particular, substitution at the -NH functionality of the quinolone motif has provided ample space for suitable functionalization and appropriate substitution at the quinolone's third, sixth, and seventh carbons, resulting in selective anticancer agents binding specifically with various drug targets.

Structural and functional insight into thiazolidinone derivatives as novel candidates for anticancer drug design: in vitro biological and in-silico strategies

The compounds 2a-2h containing a thiazolidinone pharmacophore were synthesized via hetrerocylization of thiosemicarbazones with dimethyl acetylenedicarboxylate. The hybrid molecules were evaluated for anticancer activity against the human cell lines MCF-7, T47D (human breast adenocarcinoma) and HeLa (cervical cancer). Compounds 2c showed effective cytotoxicity on MCF-7 and HeLa (GI₅₀ 6.40 ± 0.10 μM/mL and GI₅₀10.30 ± 1.09 μM/mL), and compound 2d also showed effective cytotoxicity against MCF-7 and HeLa cell lines i.e., (GI₅₀ 16.60 ± 0.21 μM/mL and GI₅₀ 15.02 ± 0.14 μM/mL). These findings were comparable to cisplatin (azane;dichloroplatinum) the standard drug (GI₅₀ 13.20 ± μM/mL and 15.10 μM/mL respectively) and consequently nominated for determination of the mode of cell death. The results revealed the cytotoxic effects of 2c and 2d by induction of apoptosis in MCF-7 and HeLa cell lines. Moreover the results were further supported by the Molecular Docking which predicts the binding interactions of the best anticancer ligands with Ribonucleotide reductase (RNR), which is essential enzyme required for de-novo synthesis of DNA precursors. Molecular dynamic simulations were also performed to determine the stability of protein-ligand complex under different simulated conditions. In addition, the computational studies including DFTs, ADMET properties suggested these compounds can act as lead molecules, for the synthesis of novel drug candidates for the treatment of specific cancer and its associated malignancies.

Phytochemistry and Anticancer Effects of Mangrove (Rhizophora mucronata Lam.) Leaves and Stems Extract against Different Cancer Cell Lines

The biologically active components of the methanol extracts of R. mucronata were identified using GC/MS. The anticancer effects of each methanol extract from the leaves and stem were evaluated against cancer and non-cancer cell lines. The MTT assay was used in order to evaluate cell viability, and the IC₅₀ and the selectivity indices were calculated in relation to a positive control (doxorubicin). The results showed that 11 and 8 different chemical compounds were found in the methanol extracts from the leaves and stems of R. mucronata, respectively. The active constituents of R. mucronata leaves and stems had anticancer effects against colon cancer (CaCo-2), with IC₅₀ levels of 127 ± 4 μg/mL and 107 ± 6 μg/mL, respectively, and on breast cancer (MCF-7), with IC₅₀ levels of 158 ± 10 μg/mL and 138 ± 4 μg/mL, respectively. These were both greater than their effects on prostate cancer (PC-3), for which they showed IC₅₀ levels of 480 ± 14 μg/mL and 294 ± 3 μg/mL, respectively. However, the anticancer effect of the stems on lung cancer (A549) (IC₅₀ = 155 ± 10 μg/mL) was greater than that of the leaves (IC₅₀ = 376 ± 9 μg/mL) in comparison with doxorubicin. Neither the stems nor the leaves of R. mucronata showed any cytotoxicity against normal cells (WI-38), with the IC₅₀ being 932 ± 30 μg/mL for the leaves and 629 ± 3 μg/mL for the stems.

Synthesis, Biocidal and Antibiofilm Activities of New Isatin-Quinoline Conjugates against Multidrug-Resistant Bacterial Pathogens along with Their In Silico Screening

Isatin-quinoline conjugates 10a-f and 11a-f were assembled by the reaction of N-(bromobutyl) isatin derivatives 3a, b with aminoquinolines 6a-c and their corresponding hydrazinyl 9a-c in good yields. The structures of the resulting conjugates were established by spectroscopic tools and showed data consistent with the proposed structures. In vitro antibacterial activity against different bacterial strains was evaluated. All tested conjugates showed significant biocidal activity with lower MIC than the first line drugs chloramphenicol and ampicillin. Conjugates 10a, 10b and 10f displayed the most potent activity against all clinical isolates. The antibiofilm activity for all tested conjugates was screened against the reference drug vancomycin using the MRSA strain. The results revealed that all conjugates had an inhibitory activity against biofilm formation and conjugate. Conjugate 11a showed 83.60% inhibition at 10 mg/mL. In addition, TEM studies were used to prove the mechanism of antibacterial action of conjugates 10a and 11a against (MRSA). Modeling procedures were performed on 10a-f and 11a-f and interestingly the results were nearly consistent with the biological activities. In addition, in silico pharmacokinetic evaluation was performed and revealed that the synthesized compounds 10a-f and 11a-f were considered drug-like molecules with promising bioavailability and high GI absorption. The results confirmed that the title compounds caused the disruption of bacterial cell membranes and could be used as potential leads for the further development and optimization of antibacterial agents.

Design, Synthesis and Anticancer Evaluation of Substituted Cinnamic Acid Bearing 2-Quinolone Hybrid Derivatives

A new series of hybrid molecules containing cinnamic acid and 2-quinolinone derivatives were designed and synthesized. Their structures were confirmed by 1H-NMR, 13C-NMR and mass analyses. All the synthesized hybrid molecules were assessed for their in vitro antiproliferative activity against more than one cancer cell lines. Compound 3-(3,5-dibromo-7,8-dihydroxy-4-methyl-2-oxoquinolin-1(2H)-ylamino)-3-phenylacrylic acid (5a) with IC50 = 1.89 μM against HCT-116 was proved to the most potent compound in this study, as compared to standard drug staurosporin. DNA flow cytometry assay of compound 5a revealed G2/M phase arrest and pre-G1 apoptosis. Annexin V-FITC showed that the percentage of early and late apoptosis was increased. The results of topoisomerase enzyme inhibition activity showed that the hybrid molecule 5a displays potent inhibitory activity compared with control.

QSAR, molecular docking, design, and pharmacokinetic analysis of 2-(4-fluorophenyl) imidazol-5-ones as anti-breast cancer drug compounds against MCF-7 cell line

The anti-proliferative activities of Novel series of 2-(4-fluorophenyl) imidazol-5-ones against MCF-7 breast cancer cell line were explored via in-slico studies which includes Quantitative structure-activity relationship QSAR, molecular docking studies, designing new compounds, and analyzing the pharmacokinetics properties of the designed compounds. From the QSAR analysis, model number one emerged the best as seen from the arithmetic assessments of (R2) = 0.6981, (R2adj) = 0.6433, (Q2) = 0.5460 and (R2pred) of 0.5357. Model number one was used in designing new derivative compounds, with higher effectiveness against estrogen positive breast cancer (MCF-7 cell line). The Molecular docking studies between the derivatives and Polo-like kinases (Plk1) receptor proved that the derivatives of 2-(4-fluorophenyl) imidazol-5-ones bind tightly to the receptor, thou ligand 24 and 27 had the highest binding affinities of -8.8 and - 9.1 kcal/mol, which was found to be higher than Doxorubicin with a docking score of -8.0 kcal/mol. These new derivatives of 2-(4-fluorophenyl) imidazol-5-ones shall be excellent inhibitors against (plk1). The pharmacokinetics analysis performed on the new structures revealed that all the structures passed the test and also the Lipinski rule of five, and they could further proceed to pre-clinical tests. They both revealed a revolution in medicine for developing novel anti-breast cancer drugs against MCF-7 cell line.

Fabrication, characterization and optimization of berberine-loaded PLA nanoparticles using coaxial electrospray for sustained drug release

BACKGROUND

Berberine (BBR) broadly found in medicinal plants has a major application in pharmacological therapy as an anticancer drug. Clinical applications of this promising natural drug are limited due to its poor water solubility and low bioavailability.

OBJECTIVE

In this study, for the first time, we synthesized core-shell BBR-loaded PLA nanoparticles (NPBs) by using coaxial electrospray (CES) to solve the poor bioavailability of BBR.

METHODS

Three-factor (feeding rate, polymeric solution concentration and applied voltage), three-level, Box-Behnken design was used for optimization of the size and particle size distribution of the prepared NPBs.

RESULTS

Based on the results of response surface methodology, the NPBs with the mean size of 265 nm and particle size distribution of 43 nm were synthesized. A TEM image was used to well illustrate the core-shell structure of the NPBs. Encapsulation efficiency and BBR loading capacity for the optimized NPBs were determined at about 81% and 7.5%, respectively. Release of NPBs was examined at pH 7.4 and 5.8. NPBs had a slower release profile than free BBR in both pH values, and the rate of BBR release was more and faster in acidic pH than in physiological one. Effects of the NPBs on the drug release were confirmed by data fitting with six kinetic models. NPBs showed an increased cytotoxic efficacy against HCT116 cells (IC₅₀ = 56 μM), while NIH3T3 cells, non-neoplastic fibroblast cells, (IC₅₀ > 150 μM) were less affected by NPBs. Flow cytometry demonstrated that the cellular uptake of NPBs were higher than BBR at different concentrations.

CONCLUSIONS

A new approach was developed in this study to prepare NPBs using the CES process for improving the efficiency and controlled BBR release. It is concluded that nano-scaled NPBs prepared by CES can improve toxicity and chemotherapeutic properties of BBR against cancerous cells. We believe that these NPBs can exhibit further potential in cancer drug delivery systems. Graphical abstract.