Synthesis and biological evaluation of some novel N-arylpyrazole derivatives as cytotoxic agents

A series of novel N-arylpyrazole derivatives, 5a–5i, were achieved from substituted phenylacetic acid via Vilsmeier–Haack reaction, hydrolysis, condensation, and aromatic substitution reaction. Their chemical structures were confirmed by ¹H NMR, ¹³C NMR, FTIR, HRMS, and elemental analysis. The newly synthesized compounds were tested for their in vitro cytotoxic activity against Bel-7402, KB, HL-60, and BGC-823 cell lines and found to possess moderate activity.     

Synthesis and evaluation of some novel tetrahydropyrimidine derivatives as antimicrobial and cytotoxic agents

Starting from the reaction of ethyl cyanoacetate with thiourea and the appropriate aldehydes, a series of new thiopyrimidine derivatives were prepared. Antibacterial evaluation results revealed that compounds 12b, 4c and 11b gave the highest antibacterial activity against all tested bacterial strains. Also, some of the novel compounds were evaluated as cytotoxic agents against liver cancer (HEPG2) cell line. It was noticed that some of the derivatives induced significant growth inhibition with IC₅₀ values (ranged from 6.35 to 9.38 μg/mL) in comparison to 5-Fluorouracil after treatment (IC₅₀: 5 μg/mL).     

Synthesis of certain 2-substituted-1H-benzimidazole derivatives as antimicrobial and cytotoxic agents

A series of 2-substituted-1H-benzimidazole derivatives were synthesized and evaluated for antimicrobial, antifungal and cytotoxic activities. The results showed that all tested compounds showed potent antimicrobial activity against some species of Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi) and fungi (Candida albicans) with minimum inhibitory concentrations (MICs) lower than 0.016 μg/mL. In contrast, all tested compounds were inactive against Staphylococcus aureus (Gram-positive bacterium). The final targets were also tested for their antitumor activity in vitro on cervical carcinoma (HeLa) cell line. Eight of the test compounds displayed more potent cytotoxic effect than doxorubicin at nanomolar concentrations. Compounds 2c and 3c exerted the strongest cytoyoxic effect with IC(50) 15 and 13 nM, respectively.     

A photochemical approach to pyridopyrroloquinoline derivatives as new potential anticancer agents

Indoloquinoline alkaloid cryptolepine and pyridocarbazole alkaloid ellipticine are of great interest because in vitro and in vivo studies revealed their good cytotoxic properties. In order to obtain some biologically active analogs of these compounds, we developped a synthesis based on the photocyclisation of tertiary N-methylated enaminones derived from cyclopentane-1,3-dione and 3 or 6-aminoquinoline. The angular cyclised compounds thus obtained were submitted to Beckmann rearrangement, preceded by the formation of a Z oxime. Finally, the delta-lactame ring was oxidized using 10% palladium/carbon in diphenylether and pyridopyrroloquinolines were obtained. These compounds and the intermediate lactams and cyclopentanopyrroloquinolines were tested in vitro on K 562 cells and A 2780 doxorubicine sensitive and resistant cells. All compounds were less effective than doxorubicine in sensitive cells but their activity wasn't decreased by MDR resistance.     

An efficient method for the synthesis of new derivatives of 2,4,6-triarylpyridines as cytotoxic agents

Research on Chemical Intermediates - New series of 2,4,6-triarylpyridines derivatives 5a–f and 6a–d were designed, synthesized and evaluated for their cytotoxic activity against breast...     

New pyrazolic compounds as cytotoxic agents

The evaluation of the in vitro cytotoxic properties of two pyrazole compounds: 1-(4-nitrophényl)-3,5-diméthylpyrazole (1) and 1,1'-di(4-nitrophényl)-5,5'-diisopropyl-3,3'-bipyrazole (2) was investigated against Hep cell line (Human laryngeal carcinoma). These two compounds showed an important cytotoxic activity on the Hep cell line, with IC(50): 8.25 microg mL(-1) for the compound 1; IC(50): 10.20 microg mL(-1) for the compound 2 while the IC(50) for adriamycine used as positive control was 3.62 microg mL(-1).     

A QSAR study and molecular design of benzothiazole derivatives as potent anticancer agents

A quantitative structure-activity relationship (QSAR) of a series of benzothiazole derivatives showing a potent and selective cytotoxicity against a tumorigenic cell line has been studied by using the density functional theory (DFT), molecular mechanics (MM ) and statistical methods, and the QSAR equation was established via a correlation analysis and a stepwise regression analysis. A new scheme determining outliers by "leave-one-out" (LOO) cross-validation coefficient (q2n-i) was suggested and successfully used. In the established optimal equation (excluding two outliers), the steric parameter (MRR) and the net charge (QFR) of the first atom of the substituent (R), as well as the square of hydrophobic parameter (lgP)2 of the whole molecule, are the main independent factors contributing to the anticancer activities of the compounds. The fitting correlation coefficient (R2) and the cross-validation coefficient (q2) values are 0.883 and 0.797, respectively. It indicates that this model has a significantly statistical quality and an excellent prediction ability. Based on the QSAR studies, 4 new compounds with high predicted anticancer activities have been theoretically designed and they are expected to be confirmed experimentally.     

Exploring the potential of fluoro-flavonoid derivatives as anti-lung cancer agents: DFT,molecular docking,and molecular dynamics techniques

The present investigation utilized in silico methodologies to explore the diverse pharmacological activities, toxicity profiles, and chemical reactivity of a series of fluoro-flavonoid compounds ( 1 – 14 ), which are secondary metabolites of plants known for their broad range of biological effects. A comprehensive strategy is utilized, incorporating methods such as prediction of activity spectra for substances (PASS) prediction, absorption, distribution, metabolism, excretion, and toxicity (ADMET) assessments, and density functional theory (B3LYP) calculations using three basis sets: 6-31G(d,p), 6-311G(d,p), and 6-311++G(d,p). Furthermore, the study employed molecular docking technique to identify target proteins, including HER2 (7JXH), EGFR (4UV7), FPPS (1YQ7), HPGDS (1V40), DCK (1P60), and KEAP1 on Nrf2 (1X2J), for the investigated compounds, with cianidanol and genistein serving as reference drugs for the docking process. The investigated fluoro-flavonoid compounds exhibited significantly greater binding affinities (ranging from −8.3 to −10.6 kcal mol⁻¹) toward HER2, HPGDS, and KEAP1 compared to the reference drugs, cianidanol and genistein, which displayed binding affinities ranging from −8.4 to −9.4 kcal mol⁻¹. Furthermore, molecular dynamics simulations were conducted to assess the stability of the protein-ligand interaction, using the root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), Radius of gyration (Rg) parameters and principle component analysis (PCA). Among the tested fluoro-flavonoid analogs, analog 11 showed a RMSD value of .15 nm with the HER2 protein target, indicating a stable interaction. Based on in silico results, it appears that the fluoro-flavonoid compound 11 has the potential to serve as a targeted anti-lung cancer drug. However, additional in vivo and in vitro studies are necessary to confirm this hypothesis.     

Synthesis of diphenylcarbazoles as cytotoxic DNA binding agents

We report the synthesis of a series of novel diphenylcarbazoles designed to interact with DNA. The compounds bearing two or three dimethylaminoalkyloxy side chains were found to bind much more tightly to DNA, preferentially at AT-rich sites, than the corresponding hydroxy compounds. The DNA binding compounds exhibit potent cytotoxic activity toward P388 leukemia cells. The 3,6-diphenylcarbazole thus represent an interesting scaffold to develop antitumor agents interacting with nucleic acids.     

Amphiphilic polymethacrylate derivatives as antimicrobial agents

We have investigated the structure-activity relationship of cationic amphiphilic polymethacrylate derivatives in antimicrobial and hemolytic assays. The polymers were prepared by radical copolymerizations of N-(tert-butoxycarbonyl)aminoethyl methacrylate and butyl methacrylate in the presence of methyl 3-mercaptopropionate as a chain transfer agent to give precursor polymers protected with a tert-butoxycarbonyl (Boc) group. Subsequent treatment of the Boc-protected polymers with TFA affords the desired cationic random copolymers. We examined antimicrobial and hemolytic activities of a series of polymers having a wide range of mole percentage of butyl groups (0-60%) in three different molecular weight (MW) ranges. The smallest polymers (MW < 2000) showed the lowest MIC and reduced hemolytic activity compared to that of the higher MW ones. In addition, polymers containing a high percentage of butyl groups are less selective for bacterial cells than their less hydrophobic counterparts.     

Synthesis,biological evaluation and molecular docking study of dihydropyrimidine derivatives as potential anticancer agents

A series of dihydropyrimidine analogues were prepared via one-pot Biginelli three-component condensation reaction and characterized by NMR, FT-IR, MS spectra, and element analysis. Subsequently, they were screened for in vitro anticancer effect. These analogues revealed good cytotoxic activity against three human cancer cell lines including MCF-7, HepG-2, and A549. Among these analogues, compounds 4d and 4h were the most potent against three cell lines. Cell viability assays indicated 4a and 4c had lower cytotoxicity. In vitro cytotoxicity study on all synthesized compounds demonstrated that introduction of electron withdrawing substituents on C4 position of phenyl ring of dihydropyrimidine contributed to the antiproliferative potency. Moreover, in silico molecular docking results stipulated a sign of good correlation between experimental activity and calculated binding affinity. It proved 4d and 4h as the strongest compounds. Binding modes of analogues proposed the involvement of hydrophobic interactions and hydrogen bonds with Eg5 active site. Structure activity relationship studies indicated that incorporating electron withdrawing substituents on C4 position of phenyl ring of dihydropyrimidine are important for this biological activity.     

Synthesis,and biological screening of chloropyrazine conjugated benzothiazepine derivatives as potential antimicrobial,antitubercular and cytotoxic agents

A series of twenty new chloropyrazine conjugated benzothiazepines (22–41) have been synthesized with 58%–95% yields. The compounds were characterized by using different spectroscopic techniques including FT-IR, ¹H NMR, ¹³C NMR spectroscopy and mass spectrometry. The synthesized compounds (22–41) and their precursor chalcones (2–21) were evaluated for antitubercular and cytotoxic activities. Additionally, compounds 22–41 were also tested for antimicrobial activity. Among the chalcone series (2–21), compounds 7 and 14 showed significant antitubercular activities (MICs 25.51 and 23.89 µM, respectively), whereas among benzothiazepines (22–41), compounds 27 and 34 displayed significant antimicrobial (MICs 38.02 µM, 19.01 µM) and antitubercular (MIC 18.10 µM) activities. Compounds 7 and 41 displayed cytotoxic activities with IC₅₀ of 46.03 ± 1 and 35.10 ± 2 µM respectively. All the compounds were evaluated for cytotoxic activity on normal human liver cell lines (L02) and found to be relatively less selective towards this cell line. The most active compounds identified through this study could be considered as potential leads for the development of drugs with possible antimicrobial, antitubercular, and cytotoxic activities.     

Synthesis and biological evaluation of novel triazole substituted pyrazolyl-methylenehydrazinyl-5-arylidene thiazolidinone derivatives as antibacterial and cytotoxic agents

Novel triazole substituted pyrazolyl-methylenehydrazinyl-5-arylidene thiazolidinone derivatives 6a–n and 7a–l were synthesized and characterized by Fourier transform infrared, ¹H and ¹³C nuclear magnetic resonance, mass spectrometry and elemental (CHN) analysis. The in vitro antibacterial (6a–n and 7a–l) and cytotoxic (6a–n) activities were evaluated for these compounds. The results revealed that the compounds 6b, 6i, 6k, 7b, 7h displayed good antibacterial activity. The compounds 6c (IC₅₀ = 5.4 μM), 6l (IC₅₀ = 6.3 μM) and 6f (IC₅₀ = 9.85 μM) were effective for inhibition of human breast cancer cell line MCF-7. Similarly, the compounds 6b (IC₅₀ = 8.7 μM) and 6c (IC₅₀ = 9.06 μM) were shown to have effective inhibition on human cervical cancer cell line Hela.     

Design and synthesis of novel 7-[(N-substituted-thioureidopiperazinyl)-methyl]-camptothecin derivatives as potential cytotoxic agents

Abstract

As part of continuing our research on diverse C-7 derivatives of camptothecin (CPT), 16 CPT derivatives bearing piperazinyl-thiourea chemical scaffold and different substituent groups have been designed, synthesized and evaluated in vitro for cytotoxicity against five tumor cell lines (A-549, MDA-MB-231, MCF-7, KB and KBvin). As a result, all the synthesized compounds showed promising in vitro cytotoxic activity against the five tumor cell lines tested, and were more potent than irinotecan. Importantly, compounds 13?g (IC₅₀ = 0.514?μM) and 13o (IC₅₀ = 0.275?μM) possessed similar or better antiproliferative activity against the multidrug-resistant (MDR) KBvin subline than that of topotecan (IC₅₀ = 0.511?μM) and merit further development as anticancer candidates for clinical trail. With these results in hand, we have a reason to conclude that incorporating piperazinyl-thiourea motifs into position-7 of camptothecin confers well cytotoxic activity against cancer cell lines, probably resulting in new anticancer drugs.     

Novel imidazole derivatives as antifungal agents: Synthesis,biological evaluation,ADME prediction and molecular docking studies

Abstract

A series of 2-(substituteddithiocarbamoyl)-N-[4-((1H-imidazol-1-yl)methyl)phenyl]acetamide derivatives was designed and synthesized to combat the increasing incidence of drug-resistant fungal infections. All synthesized compounds were characterized by IR, ¹H-NMR, ¹³C-NMR, and HRMS spectra and elemental analyses. Antifungal activity tests were performed against four different fungal strains. Molecular docking studies were performed to investigate the mode of action towards the fungal lanosterol 14α-demethylase, a cytochrome P450-dependent enzyme. ADME studies were carried out and a connection between activities and physicochemical properties of the target compounds was determined. Most of the final compounds exhibited significant activity against Candida albicans and Candida krusei with MIC₅₀ value 12.5?μg/mL. The results of in vitro anti-Candida activity, a docking study and ADME prediction revealed that the newly synthesized compounds have potential anti-Candida activity and evidenced the most active derivative, 5b (2-Pyrrolidinthiocarbonylthio-N-[4-((1H-imidazol-1-yl)methyl)phenyl]acetamide), which can be further optimized as a lead compound.     

Design,identification, antifungal evaluation and molecular modeling of chlorotetaine derivatives as new anti-fungal agents

Abstract

It is feasible to rationally modify existing bioactive components for new drug development, achieving molecules with improved biological activities. In this study, rational modification of chlorotetaine was carried out following in silico molecular modelling to enhance interactions between the fungal oligopeptide transmembrane transporter PTR22 and the ligand. The peptide obtained with the lowest docking energy, Lys-chlorotetaine (LC), displayed an improved antifungal effect compared with chlorotetaine. The lowest minimum inhibitory concentration observed against a tested pathogen was 1.47?µg/mL (Candida krusei CBS573), which was satisfactory. To thoroughly explore the detailed interactions between the transporter and LC, molecular dynamics simulation was also performed, which revealed that LC could bind to the transporter via different intermolecular interactions from chlorotetaine, and predicted electrostatic interactions (salt-bridges) would enable the more efficient release of LC. This study provides a simple and reliable method for the rational modification of oligopeptide antibiotics.     

DFT‐based QSAR study and molecular design of AHMA derivatives as potent anticancer agents

A quantitative structure–activity relationship (QSAR) of 3‐(9‐acridinylamino)‐5‐hydroxymethylaniline (AHMA) derivatives and their alkylcarbamates as potent anticancer agents has been studied using density functional theory (DFT), molecular mechanics (MM+), and statistical methods. In the best established QSAR equation, the energy (E_NL) of the next lowest unoccupied molecular orbital (NLUMO) and the net charges (Q_FR) of the first atom of the substituent R, as well as the steric parameter (MR₂) of subsituent R₂ are the main independent factors contributing to the anticancer activity of the compounds. A new scheme determining outliers by “leave‐one‐out” (LOO) cross‐validation coefficient (q) was suggested and successfully used. The fitting correlation coefficient (R²) and the “LOO” cross‐validation coefficient (q²) values for the training set of 25 compounds are 0.881 and 0.829, respectively. The predicted activities of 5 compounds in the test set using this QSAR model are in good agreement with their experimental values, indicating that this model has excellent predictive ability. Based on the established QSAR equation, 10 new compounds with rather high anticancer activity much greater than that of 34 compounds have been designed and await experimental verification. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

Structure based approach for twin-enzyme targeted benzimidazolyl-1,2,4-triazole molecular hybrids as antifungal agents

Agri-vitality of benzimidazoles and 1,2,4-triazoles against ergosterol and β-Tubulin prompted and “lead hybridization” based novel series of benzimidazolyl-1,2,4-triazoles (1–32) were designed as twin-enzyme targeted inhibitors. In silico computational tools viz. molecular docking, Lipinski parameters, Frontier molecular orbital approach and Toxicity analysis screened three benzimidazoly-1,2,4-triazoles out of 32 designed molecules, which were synthesised by multistep protocol and characterized by spectroscopic techniques. Antimycotic activity against F. verticillioides, D. oryzae, C. lunata and F. fujikuroi indicated deca fold enhanced potency of all the synthesised compounds, than the standard commercial benzimidazole fungicide, carbendazim. Compounds 8 exhibited ED₅₀ values lower than triazole fungicide, propiconazole. Remarkably, compound 8 inflicted the most promising activity against all the test fungi with ED₅₀ value ranging from 16 to 21 μg/ml better than the standard commercial fungicides used (Tilt: 20–25 μg/ml and Carbendazim:150–230 μg/ml). Ultra microscopic details revealed compound 8 not only caused aberrant distortions resulting in collapsed hyphae but also efficiently shrunken the spores resulting in reproduction inhibition, as possible cause of fungal growth inhibition.