Synthesis, biological evaluation and molecular modeling of novel series of pyridine derivatives as anticancer, anti-inflammatory and analgesic agents

Design and synthesis of some novel hybrid molecules based on 4-thiazolidinone bearing pyridine-pyrazole scaffolds: molecular docking and molecular dynamics simulations of its major constituent onto DNA gyrase inhibition

Due to multidrug resistance, microbial infections have become significant on a global level. As infections caused by several resistant bacteria and fungi severely harm mankind, scientists have developed new antibiotics to combat these infections. In order to develop novel antimicrobial agents, a series of 4-thiazolidinone-based 5-arylidene hybrids (5a-o) have been designed and synthesized to evaluate their antibacterial and antifungal activities. For the determination of the structure of a novel synthesized hybrid, various spectral techniques, e.g., IR, 1H NMR, 13C NMR, and Mass spectroscopy, were used. Two bacterial gram-negative (Escherichia coli and Pseudomonas aeruginosa), two gram-positive strains (Staphylococcus aureus and Streptococcus pyogenes), and one fungal strain (Candida albicans) were used to evaluate antimicrobial activity. Compounds 5c, 5g, and 5i were effective due to their MIC values of 62.5 μg/mL against tested bacterial strains (S. pyogenes (5c), P. aeruginosa (5g), and E. coli (5i), respectively.) and 250 μg/mL against C. albicans fungal strains, respectively. Additionally, molecular docking and 100 ns molecular dynamic simulations were carried out to investigate the stability of molecular contacts and to establish how the newly synthesized inhibitors fit together in the most stable conformations.

Design and construction of novel pyridine-pyrimidine hybrids as selective COX-2 suppressors: anti-inflammatory potential, ulcerogenic profile, molecular modeling and ADME/Tox studies

NSAIDs represent a mainstay in pain and inflammation suppression, and their actions are mainly based on inhibiting COX-1 and COX-2 enzymes.Due to the adverse effects of these drugs, especially on the stomach and heart, scientists efforts have been directed to manufacture selective COX-2 without cardiovascular side effects and with minimal effects on the stomach. The cardiovascular side effects are thought to be related to the chemical composition rather than mechanism of action of these drugs.Novel pyridopyrimidines, 9a-j, were prepared and their chemical structures were confirmed by NMR, mass and IR Spectra, and elemental analysis. The effect of the 9a-j compounds on COX-1 and COX-2 was assessed and it was found that 2-hydrazino-5-(4-methoxyphenyl)-7-phenyl-3H-pyrido[2,3-d)pyrimidin-4-one (9d) was the most potent COX-2 inhibitor (IC50 = 0.54 uM) compared to celecoxib (IC50 = 1.11 uM) with selectivity indices of 6.56 and 5.12, respectively.The in vivo inhibition of paw edema of novel compounds 9a-j was measured using carrageenan-induced paw edema method, and that 2-hydrazino-5-(4-methoxyphenyl)-7-phenyl-3H-pyrido[2,3-d)pyrimidin-4-one (9d) showed the best inhibitory activity in comparison with the other compounds and celecoxib.The gastroprotective effect of the potent derivatives 9d, 9e, 9f, 9 g and 9h was investigated. 2-Hydrazino-5-(4-methoxyphenyl)-7-phenyl-3H-pyrido[2,3-d)pyrimidin-4-one (9d) and 7-(chlorophenyl)-hydrazino-5-(4-methoxyphenyl)-3H-pyrido[2,3-d)pyrimidin-4-one (9e) showed ulcer indices comparable to celecoxib (1 and 0.5 vs 0.5, respectively). Docking studies were carried out and they confirmed the mechanistic action of the designed compoundsCommunicated by Ramaswamy H. Sarma.

Design, synthesis, in vitro, and in silico evaluations of kojic acid derivatives linked to amino pyridine moiety as potent tyrosinase inhibitors

In the present study, novel series of kojic acid derivatives conjugated to amino pyridine moiety were designed and synthesized to explore their inhibitory activity against tyrosinase. To this end, the structure of all derivatives was characterized by 1H NMR, 13C NMR, FT-IR, and elemental analysis. Next, all derivatives were evaluated against tyrosinase compared to the kojic acid as positive control and exhibited different inhibitory potencies. Furthermore, the antioxidant potential of all derivatives was determined. The kinetic analysis of the most active agent revealed that 3-hydroxy-6-(hydroxymethyl)-2-((3-nitrophenyl)(pyridin-2-ylamino)methyl)-4H-pyran-4-one (4h) binds to the enzyme in the uncompetitive mode of action. The docking analysis and molecular dynamic simulations showed considerable binding affinity and significant interactions with tyrosinase enzyme to target the melanogenesis pathway, proposing them as potent candidates to control hyperpigmentation in the future.

Integration of Hybridization Strategies in Pyridine-Urea Scaffolds for Novel Anticancer Agents: Design, Synthesis, and Mechanistic Insights

Annually, millions of new cancer cases are reported, leading to millions of deaths worldwide. Among the newly reported cases, breast and colon cancers prevail as the most frequently detected variations. To effectively counteract this rapid increase, the development of innovative therapies is crucial. Small molecules possessing pyridine and urea moieties have been reported in many of the currently available anticancer agents, especially VEGFR2 inhibitors. With this in mind, a rational design approach was employed to create hybrid small molecules combining urea and pyridine. These synthesized compounds underwent in vitro testing against breast and colon cancer cell lines, revealing potent submicromolar anticancer activity. Compound 8a, specifically, exhibited an impressive GI₅₀ value of 0.06 μM against the MCF7 cancer cell line, while compound 8h displayed the highest cytotoxic activity against the HCT116 cell line, with a GI₅₀ of 0.33 ± 0.042 μM. Notably, compounds 8a, 8h, and 8i demonstrated excellent safety profiles when tested on normal cells. Molecular docking, dynamic studies, and free energy calculations were employed to validate the affinity of these compounds as VEGFR2 inhibitors.

A Study on Repositioning Nalidixic Acid via Lanthanide Complexation: Synthesis, Characterization, Cytotoxicity and DNA/Protein Binding Studies

“Drug repositioning” is a modern strategy used to uncover new applications for out-of-date drugs. In this context, nalidixic acid, the first member of the quinolone class with limited use today, has been selected to obtain nine new metal complexes with lanthanide cations (La³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺); the experimental data suggest that the quinolone acts as a bidentate ligand, binding to the metal ion via the keto and carboxylate oxygen atoms, findings that are supported by DFT calculations. The cytotoxic activity of the complexes has been studied using the tumoral cell lines, MDA-MB-231 and LoVo, and a normal cell line, HUVEC. The most active compounds of the series display selective activity against LoVo. Their affinity for DNA and the manner of binding have been tested using UV–Vis spectroscopy and competitive binding studies; our results indicate that major and minor groove binding play a significant role in these interactions. The affinity towards serum proteins has also been evaluated, the complexes displaying higher affinity towards albumin than apotransferrin.

Antiproliferative Activity of Some Newly Synthesized Substituted Nicotinamides Candidates Using Pyridine-2(1H) thione Derivatives as Synthon

Some new pyridinethione and thienopyridine derivatives have been synthesized and evaluated for their antiproliferative activity using the MTT assay. Nicotinamide derivatives 3 have been synthesized and used for the preparation of new condensed thieno [2,3-b]pyridines by their reactions with active halo compounds. Finally the synthesized thienopyridine underwent ring closure whenever possible through boiling in a solution of sodium ethoxide. The antiproliferative evaluation against (HCT-116, HepG-2, and MCF-7) human cancer cells and one human healthy cell line (BJ-1) revealed that compounds 3b, 4c-5d, 7b-12a, 10d, and 13b have interesting antitumor activity specifically as antihepatocellular and anticolon cellular carcinoma agents. Besides, the docking results for most active derivatives were in agreement with the in vitro antitumor results.

A Therapeutic Journey of Pyridine-Based Heterocyclic Compounds as Potent Anticancer Agents: A Review (From 2017 to 2021)

Pyridine derivatives are the most common and significant heterocyclic compounds, which show their fundamental characteristics to various pharmaceutical agents and natural products. Pyridine derivatives possess several pharmacological properties and a broad degree of structural diversity that is considered most valuable to explore the novel therapeutic agents. These compounds have an extensive range of biological activities such as antifungal, antibacterial, anticancer, anti-obesity, anti-inflammatory, antitubercular, antihypertensive, antineuropathic, antihistaminic, antiviral activities, and antiparasitic. The potent therapeutic properties of pyridine derivatives allow medicinal chemists to synthesize novel and effective chemotherapeutic agents. Consequently, the imperative objective of this comprehensive review is to summarize and investigate the literature regarding recent advancements in pyridine-based heterocycles to treat several kinds of cancer. Furthermore, the performances of pyridine derivatives were compared with some standard drugs including etoposide, sorafenib, cisplatin, and triclosan against different cancer cell lines. We hope this study will support the new thoughts to pursue the most active and less toxic rational designs.

Synthesis, molecular docking, and in silico ADMET studies of 4-benzyl-1-(2,4,6-trimethyl-benzyl)-piperidine: Potential Inhibitor of SARS-CoV2

Nowadays, over 200 countries face a wellbeing emergency because of epidemiological disease COVID-19 caused by the SARS-CoV-2 virus. It will cause a very high effect on the world's economy and the worldwide health sector. The present work is an investigation of the newly synthesized 4-benzyl-1-(2,4,6-trimethyl-benzyl)-piperidine (M1BZP) molecule's inhibitory potential against important protein targets of SARS-CoV-2 using computational approaches. M1BZP crystallizes in monoclinic type with P1211 space group. For the title compound M1BZP, spectroscopic characterization like ¹H NMR, ¹³C NMR, FTIR, were carried out. The geometry of the compound had been optimized by the DFT method and its results were compared with the X-ray diffraction data. The calculated energies for the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) showed the stability and reactivity of the title compound. Intermolecular interactions in the crystal network were determined using Hirshfeld surface analyses. The molecular electrostatic potential (MEP) picture was drawn using the same level of theory to visualize the chemical reactivity and charge distribution on the molecule. Molecular docking study performed for the synthesized compound revealed an efficient interaction with the COVID-19 protease and resulted in good activities. We hope the present study would help workers in the field to develop potential vaccines and therapeutics against the novel coronavirus. Virtual ADME studies were carried out as well and a relationship between biological, electronic, and physicochemical qualifications of the target compound was determined. Toxicity prediction by computational technique for the title compound was also carried out.

Design and Efficient Synthesis of Novel 4,5-Dimethylthiazole-Hydrazone Derivatives and their Anticancer Activity

Background::

Recently, researchers have been warning about the increased mortality of the various cancer types. Also, the lung adenocarcinoma and the glioma types are burning issues for world's health due to late or wrong diagnosis and/or insufficient treatment methods. For this purpose, our research group designed and synthesized novel 4,5-dimethyl thiazole-hydrazone derivatives which were tested against cancer and normal cell lines to understand the structureactivity relationship (SAR).

Method::

The lead compounds were obtained by reacting 2-(substituted aryl-2-ylmethylene) hydrazin-1-carbothioamide with 3-chloro-2-butanone derivatives. The structural elucidation of the compounds was performed by 1H-NMR, 13C-NMR, and LC/MS-IT-TOF spectral and elemental analyses. The synthesized compounds were tested in vitro for the anticancer activity against A549 human lung adenocarcinoma and C6 rat glioma cells and investigated for which pathway to induce cell death. Also, the docking study of the active compounds was achieved to understand the SAR.

Result and Discussion::

The targeted compounds (2a-2l) were synthesized successfully above 70% yields, and the analysis findings proved their purity. In general, the results of activity studies displayed significant effects against at least one cell line, except compounds 2e (indol-3-yl) and 2h (4-dimethylaminophenyl). Furthermore, compounds 2b and 2f displayed potential anticancer activity. With the help of molecular docking study, a potential selectivity of compound 2f was observed for type II protein kinase. On the other hand, compound 2b interacted with the active site nearly the same as Dasatinib. Therefore, these two compounds could be used as a base on developing selective anticancer drugs.

Conclusion::

Pyridin-2-yl (2b) derivative was found to be a favorable molecule with high anticancer potency against C6 and A549 cell lines. Additionally, 1-naphthyl (2f) derivative was a worthy compound for potential selectivity. In future studies, it will be our priority to focus on developing derivatives of these two compounds (2b and 2f) and elucidate their mechanisms.

Solvent effects on the electronic and optical properties of Ni(II), Zn(II), and Fe(II) complexes of a Schiff base derived from 5-bromo-2-hydroxybenzaldehyde

In this article, the electronic, optical, and charge transfer properties of a Schiff base ligand prepared using 5-bromo-2-hydroxybenzaldehyde and ethyl 6-acetyl-2-amino-4,5,6,7-tetrahydrothieno[2,3- c]pyridine-3-carboxylate (C19H19BrN2O4S) and its Fe(II) (C19H30BrN2O10SClFe), Ni(II) (C19H28BrN2O9SClNi), and Zn(II) (C19H28BrN2O9SClZn) complexes are described based on different solvents environments and supported by theoretical calculations. Theoretical calculations are carried out using density functional theory (DFT/UB3LYP/LANL2DZ). The optical densities, optical band gaps, and refractive indices of the ligand and its Fe(II), Ni(II), and Zn(II) complexes in different solvent environments are obtained. The reorganization energies are calculated to determine the charge transfer rate of the studied compounds using both experimental and theoretical data. These experimental and theoretical results show that the ligand and its metal complexes can be used for optoelectronic applications and charge transfer materials in organic light-emitting diode applications.

Pyrrole-2,5-dione analogs as a promising antioxidant agents: microwave-assisted synthesis, bio-evaluation, SAR analysis and DFT studies/interpretation

A new series of pyrrole analogs were developed via the microwave irradiation synthesis. Consequently, got a high yield of the products. As pyrroles are familiar for showing various biological properties, all obtained compounds were screened for their antioxidant properties, most of the compounds showing significant activity. In fact, the motifs 5e, 5g, 5h and 5m showed outstanding antioxidant properties. Further, to enlighten the biologically energetic behavior underlying the antioxidant activity, compounds DFT studies were performed. Noteworthy results have been attained and the structure activity relationship (SAR) was discussed with the support of this results. It was found that highly biological active compounds exhibited a low HOMO-LUMO energy gap (Eg) and the high Eg value compounds show very low/negligible or inactive antioxidant activities. In other cases, compounds containing high HOMO energy levels also provide high antioxidant activity. The thought-provoking point of our results is that theoretical descriptors of the HOMO-LUMO energy gap and the highest occupied molecular orbital energy are important descriptors in the bioorganic research to support the biological experiments.

Design, One Pot Synthesis and Molecular Docking Studies of Substituted-1H-Pyrido[2,1-b] Quinazolines as Apoptosis-Inducing Anticancer Agents

Objective:

The present study focused to build pyridine and quinazoline rings in a single molecule and designed a new fused Pyrido[2,1-b] quinazoline to have a better pharmacological activity.

Material and Methods:

A three component, one-pot synthesis of substituted-1H-Pyrido[2,1-b] quinazoline derivatives has been described by conventional and microwave synthesis using triflic acid as catalyst. These compounds were screened for in vitro cytotoxic activity against the panel of cancer cell lines A549, NCI-H460, HT-29, HCT-15, DU-145, and HFL.

Results:

Among the tested compounds, 11-(1-benzyl-1H-indol-3-y1)-2, 3, 4, 11-tetrahydro-1H-pyrido[2,1-b] quinazoline (4i) showed most potent cytotoxicity against A549 and NCI-H460 lung cancer cell lines with IC₅₀ values 4.57±0.25 and 5.53±0.49 µM, respectively. Moreover, compound 4i was found to be most potent considerable cell growth inhibition with GI₅₀ values of 2.70±0.18 and 3.24±0.40 µM against A549 and NCI-H460 cell lines, respectively. In addition, induction of apoptosis for compound 4i on A549 was investigated by morphological changes, Acridine orange/ethidium bromide (AO/EB) and DAPI staining. Furthermore, a strong anti-clonogenic effect of compound 4i on lung cancer cells was observed. The flow cytometric analysis investigation reveals that compound 4i arrests the A549 cancer cell lines at the G0/G1 phase of the cell cycle. Molecular docking were also performed on 4i, 4j, and erlotinib to predict the binding mode towards the EGFR kinase (PDB code: 1M17) and the compounds have displayed similar interactions and compared with erlotinib.

Conclusion:

Overall, these findings could suggest that the compound 4i would be an ideal lead as an anticancer agent.

Pyridine azo disperse dye derivatives and their selenium nanoparticles (SeNPs): synthesis, fastness properties, and antimicrobial evaluations

Aim

Aiming to produce pyridine azo disperse dyes with good fastness properties and promising antimicrobial activity, a number of novel systems of polyfunctionalized pyridine azo dyes and their selenium nanoparticles (SeNPs) were synthesized.

Materials and methods

The synthesized products were formed by the reaction of diazotized aniline derivatives or diazotized amino antipyrene with any of dibenzoyl methane or benzoyl acetone and cyanoacetamide in boiling ethanolic sodium ethoxide. The structures of the newly synthesized compounds were elucidated by elemental analysis and spectral data. Moreover, (SeNPs) of the pyridine azo disperse dyes were characterized by Ultra-Violet -Visible spectrophotometry, dynamic light scattering , X-ray diffraction, and transmission electron microscope analysis. On the other hand, the synthesized dyes and its (SeNPs) were applied for disperse dyeing of nylon 66 and their fastness properties were measured, such as washing, rubbing, perspiration, and light fastness. In addition, the antimicrobial activities for all the synthesized compounds and for (SeNPs) prepared compounds (2bN, 2cN, 2fN, 2gN, 2hN) were evaluated.

Results

Compounds 2bN, 2c, 2cN, 2fN, 2gN, 2h, 2hN, and 2i were the most active compounds against all Gram-positive and Gram-negative bacterial species. While, compounds 2b, 2f, 2g, and 5b were the most active toward some of the bacterial strains (at least two from the selected four strains). Moreover, compounds 2bN, 2cN, 2fN, 2gN, 2h, 2hN showed higher activity toward the fungal strain. Also, the minimal inhibitory concentrations for all the most active compounds were determined.

Conclusion

Finally, all the (SeNPs) compounds revealed higher activity against bacterial and fungal strains than the other synthesized compounds.

Novel Tri-substituted Thiazoles Bearing Piperazine Ring: Synthesis and Evaluation of their Anticancer Activity

Background:

Cancer cells are described as an unregulated growth and spread of abnormal cells. Recently, cancer has become the most important major reason for deaths in the world.

Methods:

For anticancer activity, we have used the MTT method and determine the early/late apoptosis by flow cytometry.

Results:

The title compounds were procured by reacting 2-chloro-N-[4-(pyridin-4-yl)thiazol-2- yl]acetamide with some substituted piperazine derivatives. The in vitro anticancer activity of synthesized compounds was tested against C6 rat glioma cells and A549 human lung carcinoma cells. As a result, the compounds 3d, 3e, 3f and 3g have shown anticancer activity against both cell line.

Conclusion:

Specifically, compound 3f was determined as the most active compound against C6 rat glioma cells. Also, as understood, the core structure which is substituted with piperazine bridge, the heterocyclic aromatic derivatives are more active than phenyl or benzyl derivatives.

Synthesis, computational quantum chemical study, in silico ADMET and molecular docking analysis, in vitro biological evaluation of a novel sulfur heterocyclic thiophene derivative containing 1,2,3-triazole and pyridine moieties as a potential human topoisomerase IIα inhibiting anticancer agent

Computational quantum chemical study and biological evaluation of a synthesized novel sulfur heterocyclic thiophene derivative containing 1,2,3-triazole and pyridine moieties namely BTPT [2-(1-benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-6-methoxy-4-(thiophen-2-yl) pyridine] was presented in this study. The crystal structure was determined by SCXRD method. For the title compound BTPT, spectroscopic characterization like ¹H NMR, ¹³C NMR, FTIR, UV-vis were carried out theoretically by computational DFT method and compared with experimental data. Druglikeness parameters of BTPT were found through in silico pharmacological ADMET properties estimation. The molecular docking investigation was performed with human topoisomerase IIα (PDB ID:1ZXM) targeting ATP binding site. In vitro cytotoxicity activity of BTPT/doxorubicin were examined by MTT assay procedure against three human cancer cell lines A549, PC-3, MDAMB-231 with IC50 values of 0.68/0.70, 1.03/0.77 and 0.88/0.98 μM, respectively. Our title compound BTPT reveals notable cytotoxicity against breast cancer cell (MDAMB-231), moderate activity with human lung cancer cell (A-549) and less inhibition with human prostate cancer cell (PC-3) compared to familiar cancer medicine doxorubicin. From the results, BTPT could be observed as a potential candidate for novel anticancer drug development process.

In vitro leishmanicidal activity and theoretical insights into biological action of ruthenium(II) organometallic complexes containing anti-inflammatories

Leishmaniasis, a neglected tropical disease caused by protozoans of the genus Leishmania, kills around 20-30 thousand people in Africa, Asia, and Latin America annually and, despite its potential lethality, it can be treated and eventually cured. However, the current treatments are limited owing to severe side effects and resistance development by some Leishmania. These factors make it urgent to develop new leishmanicidal drugs. In the present study, three ruthenium(II) organometallic complexes containing as ligands the commercially available anti-inflammatories diclofenac (dic), ibuprofen (ibu), and naproxen (nap) were synthesized, characterized, and subjected to in vitro leishmanicidal activity. The in vitro cytotoxicity assays against Leishmania (L.) amazonensis and Leishmania (L.) infantum promastigotes have shown that complexes [RuCl(dic)(η⁶-p-cymene)] (1) and [RuCl(nap)(η⁶-p-cymene)] (3) were active against both Leishmania species. Complex [RuCl(ibu)(η⁶-p-cymene)] (2) has exhibited no activity. The IC₅₀ values for the two active complexes were respectively 7.42 and 23.55 μM, for L. (L.) amazonensis, and 8.57 and 42.25 μM, for L. (L.) infantum. Based on the toxicological results and computational analysis, we proposed a correlation between the complexes and their activity. Our results suggest both complexation to ruthenium(II) and ligands structure are key elements to leishmanicidal activity.

Synthesis, spectroscopic, thermal, antimicrobial and electrochemical characterization of some novel Ru(iii), Pt(iv) and Ir(iii) complexes of pipemidic acid

Three new solid complexes of pipemidic acid (Pip-H) with Ru3+, Pt4+ and Ir3+ were synthesized and characterized. Pipemidic acid acts as a uni-dentate chelator through the nitrogen atom of the -NH piperazyl ring. The spectroscopic data revealed that the general formulas of Pip-H complexes are [M(L) n (Cl) x ]·yH2O ((1) M = Ru3+, L: Pip-H, n = 3, x = 3, y = 6; (2) M = Pt4+, L: Pip-NH4, n = 2, x = 4, y = 0 and (3) M = Ir3+, L: Pip-H, n = 3, x = 3, y = 6). The number of water molecules with their locations inside or outside the coordination sphere were assigned via thermal analyses (TG, DTG). The DTG curves refer to 2-3 thermal decomposition steps where the first decomposition step at a lower temperature corresponds to the loss of uncoordinated water molecules followed by the decomposition of Pip-H molecules at higher temperatures. Thermodynamic parameters (E*, ΔS*, ΔH* and ΔG*) were calculated from the TG curves using Coats-Redfern and Horowitz-Metzeger non-isothermal models. X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques were carefully used to assign properly the particle sizes of the prepared Pip-H complexes. The biological enhancement of Pip-H complexes rather than free chelate were assessed in vitro against four kinds of bacteria G(+) (Staphylococcus epidermidis and Staphylococcus aureus) and G(-) (Klebsiella and Escherichia coli) as well as against the human breast cancer (MCF-7) tumor cell line.

Pyridine-Ureas as Potential Anticancer Agents: Synthesis and In Vitro Biological Evaluation

In our endeavor towards the development of effective anticancer agents, a novel series of pyridine-ureas 8a⁻n were synthesized. All the newly prepared derivatives were evaluated in vitro for their growth inhibitory activity towards the proliferation of breast cancer MCF-7 cell line. Compounds 8e and 8n were found to be the most active congeners against MCF-7 cells (IC₅₀ = 0.22 and 1.88 µM after 48 h treatment; 0.11 and 0.80 µM after 72 h treatment, respectively) with increased activity compared to the reference drug doxorubicin (IC₅₀ = 1.93 µM). Moreover, eight selected pyridines 8b, 8d, 8e, 8i, 8j and 8l⁻n were evaluated for their in vitro anticancer activity according to the US-NCI protocol. Pyridines 8b and 8e proved to be the most effective anticancer agents in the NCI assay with mean inhibition = 43 and 49%, respectively. Both 8b and 8e exhibited anti-proliferative activity against all tested cancer cell lines from all subpanels growth inhibition (GI for 8b; 12⁻78%, GI for 8e; 15⁻91%). Pyridines 8b and 8e were screened in vitro for their inhibitory activity against VEGFR-2. Both compounds inhibited VEGFR-2 at micromolar IC₅₀ values 5.0 ± 1.91 and 3.93 ± 0.73 µM, respectively. The most active pyridines were filtered according to the Lipinski and Veber rules and all of them passed these filters. Finally, several ADME descriptors were predicted for the active pyridines through a theoretical kinetic study.

Design, synthesis, biological assessment and molecular docking studies of new 2-aminoimidazole-quinoxaline hybrids as potential anticancer agents

In a search for novel antiproliferative agents, a series of quinoxaline derivatives containing 2-aminoimidazole (8a-8x) were designed and synthesized. The structures of synthesized compounds were confirmed by IR, ¹H NMR, ¹³C NMR, Mass Spectroscopy and analyzed using HSQC, COSY, ROESY, HMBC techniques. The anticancer activity of all derivatives were evaluated for colon cancer and breast cancer cell lines by the MTT assay and acridine orange/ethidium bromide double staining method. The anti-cancer effect in human colon cancer (HCT-116) and breast cancer (MCF-7) cell lines exhibited that compounds 8a, 8s, 8t, 8w, 8x appeared as potent antiproliferative agents and especially inhibited the human colon cancer cell proliferation with percentage of inhibition by over 50%. The most active compound was (E)-4-phenyl-1-((quinoxalin-2-ylmethylene)amino)-1H-imidazol-2-amine (8a) with the highest inhibition for MCF-7 (83.3%) and HCT-116 (70%) cell lines after 48 and 24h, respectively. Molecular docking studies of these derivatives within c-kit active site as a validated target might be suggested them as appropriate candidates for further efforts toward more potent anticancer compounds.

Synthesis and physicochemical characterizations of coordination between palladium(ii) metal ions with floroquinolone drugs as medicinal model against cancer cells: novel metallopharmaceuticals

Three new complexes of palladium(ii) floroquinolone drugs (levofloxacin (HLVX), pefloxacin mesylate (HPFX) and lomefloxacin (HLMX)) were prepared in alkaline media at pH = 9.

Interaction of vasicine with calf thymus DNA: Molecular docking, spectroscopic and differential scanning calorimetric insights

The present study brings out the interaction between vasicine, an alkaloid of Adhatoda vasica Nees with double stranded DNA [corrected]. The physico-chemical interaction between small molecules and nucleic acids is a major area of focus in screening drugs against various cancers. Molecular probing in our study using Molecular Operating Environment (MOE) has revealed interaction of vasicine with DNA double helix. Here we report the interaction of vasicine with Calf thymus DNA. We present for the first time the results obtained from UV-visible, fluorescence spectroscopic and differential scanning calorimetric techniques that suggest a moderate to strong electrostatic, hydrophobic and van der Waals interactions mediating the DNA binding properties of vasicine, leading to disruption of DNA secondary structure.