Biological activity and molecular docking studies of some new quinolines as potent anticancer agents

Highly Brominated Quinolines: Synthesis, Characterization, and Investigation of Anticancer Activities Supported by Molecular Dynamics

In this study, we synthesized and characterized novel brominated methoxyquinolines (7 and 11) and nitrated bromoquinoline (17) derivatives with potential antiproliferative activity against cancer cell lines. Starting from 1,2,3,4-tetrahydroquinoline (THQ, 1), a series of brominated quinoline compounds was obtained via regioselective bromination and subsequent reactions. The structure of the key compound, 3,5,6,7-tetrabromo-8-methoxyquinoline (7), was confirmed using 1D and 2D NMR techniques. Additionally, unexpected bromination of 3,6,8-trimethoxyquinoline (5) yielded 5,7-dibromo-3,6-dimethoxy-8-hydroxyquinoline (11), allowing functionalization of both rings in the quinoline. The direct nitration of 6,8-dibromoquinoline (6) yielded the corresponding 5-nitro derivative (17), a precursor to amino derivatives that activate the bromine group on the ring. Antiproliferative activities of these derivatives (7, 11, 17) were assessed against C6, HeLa, and HT29 cancer cell lines using the BCPE assay. Compounds 7, 11, and 17 exhibited significant inhibitory effects, with compound 11 showing the highest activity (IC50 values of 5.45-9.6 μg/mL). Furthermore, the cytotoxicity of these compounds was evaluated using the LDH assay, indicating lower cytotoxic effects compared to the control drug 5-FU. The ability of compounds 11 and 17 to induce apoptosis was confirmed through DNA laddering, while compound 7 showed no such effect. Compounds 7 and 11 inhibited human topoisomerase I, a critical enzyme for DNA replication and repair, with significant binding energies determined by MM-PBSA studies. The wound healing assay demonstrated that compound 17 effectively inhibited the migration of HT29 cells. These findings highlight the potential of these novel quinoline derivatives as effective anticancer agents, warranting further investigation into their mechanisms of action and therapeutic applications.

Pd-, Cu-, and Ni-Catalyzed Reactions: A Comprehensive Review of the Efficient Approaches towards the Synthesis of Antibacterial Molecules

A strong synthetic tool for many naturally occurring chemicals, polymers, and pharmaceutical substances is transition metal-catalyzed synthesis. A serious concern to human health is the emergence of bacterial resistance to a broad spectrum of antibacterial medications. The synthesis of chemical molecules that are potential antibacterial candidates is underway. The main contributions to medicine are found to be effective in transition metal catalysis and heterocyclic chemistry. This review underlines the use of heterocycles and certain effective transition metals (Pd, Cu, and Ni) as catalysts in chemical methods for the synthesis of antibacterial compounds. Pharmaceutical chemists might opt for clinical exploration of these techniques due to their potential.

Alkoxy-functionalised dihydropyrimido[4,5-b]quinolinones enabling anti-proliferative and anti-invasive agents

In this communication, we explored the synthesis of novel alkoxy-functionalised dihydropyrimido[4,5-b]quinolinones using a microwave-assisted multicomponent reaction. All the synthesized molecules were screened for anti-proliferative and anti-invasive activity against glioblastoma cells. 5c shows the most potent anti-proliferative activity with a half maximal effective concentration of less than 3 μM against primary patient-derived glioblastoma cells. 5c effectively inhibited invasion and tumor growth of 3D primary glioma cultures in a basement membrane matrix. This suggests that the novel compounds could inhibit both the proliferation and invasive spread of glioma and they were selected for further study.

Molecular Docking and In Vivo Biological Studies of Sodium Salt of 3-(4-Methyl-2-oxo-2-H-quinoline-7-yloxy)-3-phenylacrylic Acid As Anticancer Agent

Quinoline derivatives possess several therapeutic properties. Aim: studying the anticancer effect of 3-(4-methyl-2-oxo-2-H-quinoline-7-yloxy)-3-phenylacrylic acid's sodium solution on the Ehrlich ascites carcinoma (EAC). Median lethal dose (LD50) and dose response curve was determined for sodium salt solution of 3-(4-methyl-2-oxo-2-H-quinoline-7-yloxy)-3-phenylacrylic acid, then diving a group of one hundred Swiss albino mice, which are all females, into five groups: group 1: (negative control) where intraperitoneally injected with saline into mice for 10 successive days; group 2 (positive control), also namely (EAC-bearing group): where the EAC cells were intraperitoneally injected into mice (2.5 × 106 cells/mouse) only one time on the first day; group 3 which is defined as the (therapeutic group) where the Na+ salt of the synthetic compound was injected into the peritoneum of the mice (2.5 mg/kg) the very first day after the injection of the EAC, then the compound was injected every two days for a period of 10 days; group 4 which is the (preventive group) where the sodium salt of the synthetic compound (2.5 mg/kg) was injected in the peritoneum of the mice the day before the injection of the EAC, then the compound was successively injected every day for a period of ten days; and group 5 which is the (drug group) in which mice were repeatedly injected) in their peritoneum with the sodium salt of the synthetic compound (2.5 mg/kg on a daily basis over a period of ten days. On the eleventh day of the trial, EAC cells were harvested from each mouse in a heparinized saline, in addition to blood samples, liver and kidney tissues which are also collected. Molecular docking showed that compound's sodium salt was docked into (PDB: 2R7G) and (PDB: 2R3I), which are the retinoblastoma protein receptor and the cyclin D-1 receptor respectively. Compared to those in the positive control group, mice in both the therapeutic and preventive groups, has shown a significant decrease in MDA, cyclin D-1 levels in the tissues of both liver and kidney tissues, in addition to the serum ALT, AST, CK-MB, and LDH activities, and the serum urea and creatinine concentration. However, mice in the formerly mentioned groups, both therapeutic and preventive groups, have shown an increase in the serum albumin, total protein, retinoblastoma protein in both liver and kidney tissues as well as the total antioxidant capacity, when compared to mice in the positive control group. It is worth mentioning that histopathological findings have confirmed that. Sodium salt of 3-(4-methyl-2-oxo-2H-quinoline-7-yloxy)-3-phenylacrylic acid showed potential in vivo anticancer and antioxidant effects against Ehrlich ascites carcinoma cells; (EAC cells).

Nitrogen Containing Heterocycles as Anticancer Agents: A Medicinal Chemistry Perspective

Cancer is one of the major healthcare challenges across the globe. Several anticancer drugs are available on the market but they either lack specificity or have poor safety, severe side effects, and suffer from resistance. So, there is a dire need to develop safer and target-specific anticancer drugs. More than 85% of all physiologically active pharmaceuticals are heterocycles or contain at least one heteroatom. Nitrogen heterocycles constituting the most common heterocyclic framework. In this study, we have compiled the FDA approved heterocyclic drugs with nitrogen atoms and their pharmacological properties. Moreover, we have reported nitrogen containing heterocycles, including pyrimidine, quinolone, carbazole, pyridine, imidazole, benzimidazole, triazole, β-lactam, indole, pyrazole, quinazoline, quinoxaline, isatin, pyrrolo-benzodiazepines, and pyrido[2,3-d]pyrimidines, which are used in the treatment of different types of cancer, concurrently covering the biochemical mechanisms of action and cellular targets.

Influence of derivatives of 2-((6-r-quinolin-4-yl)thio)acetic acid on rhizogenesis of Paulownia clones

In recent years, the demand for effective and low-toxic stimulators of rhizogenesis, which are used in microclonal propagation of plants, has been increasing in Ukraine. One of the promising directions in the search for effective compounds is molecular modeling based on known natural and synthetic compounds. The development of new highly effective and low-toxic biologically active compounds is largely based on derivatives of nitrogen-containing heterocycles, and quinoline occupies a significant place among them. Modern methods of chemometric analysis make it possible to find certain regularities in the "chemical structure – biological activity" and to select the most promising compounds for experimental research. The values of lipophilicity log P for neutral forms and the value of the distribution coefficient log D at pH = 7 were obtained by quantum chemical calculation. The values of log P and log D of the studied compounds are in the most favourable interval for overcoming the biological membranes of the cells of the root system, depending on the pH of the environment. According to Lipinski’s "rule of five", all studied compounds can show high biological activity. The toxicity of compounds of 2-((6-R-quinolin-4-yl)thio)acetic acid derivatives was evaluated by computer programs and experimentally. Among the derivatives of 2-((6-R-quinolin-4-yl)thio)acetic acid, the most toxic compounds were those that did not have alkoxy substituents in the 6th position of the quinoline ring. Sodium salts are more toxic than the corresponding acids. This is due to an increase in the bioavailability of ionized compounds. Derivatives of 2-((6-R-quinolin-4-yl)thio)acetic acid (sodium salt of 2-((quinolin-4-yl)thio)acetic acid (QAC-5) showed the greatest toxic effect on the model of the study of progressive sperm motility) and 2-((quinolin-4-yl)thio)acetic acid (QAC-1), which will reduce this indicator by 15–20% compared to intact. The toxicity assessment of the studied compounds made it possible to determine a number of factors of the structure of molecules which affect the level of toxic action of 2-((6-R-quinolin-4-yl)thio)acetic acid derivatives and the directions of creation of non-toxic growth stimulants in this series. The impact on rhizogenesis during microclonal reproduction in vitro in explants Paulownia clone 112 and further adaptation of microplants in vivo hybrid molecules of quinoline and acetic acid, which are analogues of known growth stimulants, was studied. A number of factors influencing the level of influence on rhizogenesis of the action of derivatives of 2-((6-R-quinolin-4- yl)thio)acetic acid and directions of creation of highly active substances in this series was defined. The studied compounds showed a high stimulating effect on rhizogenesis in vitro in Paulownia explants. It was established that the sodium salt of 2-((quinolin-4-yl)thio)acetic acid was the greatest stimulator of rhizogenesis compared to the corresponding original acid. The presence of alkoxy groups in the 6th position and methyl in the 2nd position of the quinoline ring of 2-((6-R-quinolin-4-yl)thio)acetic acid reduced the activity of the compounds. The selection of new effective, low-toxic, less expensive substances was carried out for further testing as potential stimulators of rhizogenesis for microclonal propagation of plants.

Oxadiazole: A highly versatile scaffold in drug discovery

As a pharmacologically important heterocycle, oxadiazole paved the way to combat the problem associated with the confluence of many commercially available drugs with different pharmacological profiles. The present review focuses on the potential applications of five-membered heterocyclic oxadiazole derivatives, especially 1,2,4-oxadiazole, 1,2,5-oxadiazole, and 1,3,4-oxadiazole, as therapeutic agents. Designing new hybrid molecules containing the oxadiazole moiety is a better solution for the development of new drug molecules. The designed molecules may accumulate a biological profile better than those of the drugs currently available on the market. The present review will guide the way for researchers in the field of medicinal chemistry to design new biologically active molecules based on the oxadiazole nucleus. Antitubercular, antimalarial, anti-inflammatory, anti-HIV, antibacterial, and anticancer activities of various oxadiazoles have been reviewed extensively here.