Synthesis, biological activities, and molecular docking studies of triazolo[4,3-b]triazine derivatives as a novel class of α-glucosidase and α-amylase inhibitors.

In diabetes mellitus, amylase and glucosidase enzymes are the primary triggers. The main function of these enzymes is to break macromolecules into simple sugar units, which directly affect blood sugar levels by increasing blood permeability. To overcome this metabolic effect, there is a need for a potent and effective inhibitor capable of suppressing the enzymatic conversion of sugar macromolecules into their smaller units. Herein, we reported the discovery of a series of substituted triazolo[4,3-b][1,2,4]triazine derivatives as α-glucosidase and α-amylase inhibitors. All target compounds demonstrated significant inhibitory activities against α-glucosidase and α-amylase enzymes compared with acarbose as the positive control. The most potent compound 10k, 2-[(6-phenyl-[1,2,4]triazolo[4,3-b][1,2,4]triazin-3-yl)thio]-N-[4-(trifluoromethyl)phenyl]acetamide, demonstrated IC50 values of 31.87 and 24.64 nM against α-glucosidase and α-amylase enzymes, respectively. To study their mechanism of action, kinetic studies were also done, which determined the mode of inhibition of both enzymes. Molecular docking was used to confirm the binding interactions of the most active compounds.

Design, synthesis, and biological evaluation of new biaryl derivatives of cycloalkyl diacetamide bearing chalcone moiety as type II c-MET kinase inhibitors.

Many human cancers have been associated with the deregulation of the mesenchymal-epithelial transition factor tyrosine kinase (MET) receptor, a promising drug target for anticancer drug discovery. Herein, we report the discovery of a novel structure of potent chalcone-based derivatives type II c-Met inhibitors which are comparable to Foretinib (IC50 = 14 nM) as a potent reference drug. Based on our design strategy, we also expected an anti-tubulin activity for the compounds. However, the weak inhibitory effects on microtubules were confirmed by cell cycle analyses implicated that the observed cytotoxicity against HeLa cells probably was not derived from tubulin inhibition. Compounds 14q and 14k with IC50 values of 24 nM and 45 nM, respectively, demonstrated favorable inhibition of MET kinase activity, and desirable bonding interactions in the ligand-MET enzyme complex stability in molecular docking studies.

Synthesis, α-Glucosidase inhibitory activity and docking studies of Novel Ethyl 1,2,3-triazol-4-ylmethylthio-5,6-diphenylpyridazine-4-carboxylate derivatives.

In this work, a novel series of pyridazine-triazole hybrid molecules were prepared and evaluated as inhibitors of rat intestinal α-glucosidase enzyme. Amongst all newly synthesized compounds, 10k showed good inhibition in the series with IC50 value of 1.7 µM which is 100 folds stronger than positive control, acarbose. The cytotoxicity revealed that this compound is not toxic against normal cell line, HDF. The docking studies showed that triazole ring plays an important role in the binding interactions with the active site. The insertion of compound 10k into the active pocket of α-glucosidase and formation of hydrogen bonds with Leu677 was observed from docking studies. The kinetic studies revealed that this compound has uncompetitive mode of inhibition against α-glucosidase enzyme.

Synthesis of novel 2-acetamide-5-phenylthio-1,3,4-thiadiazole-containing phenyl urea derivatives as potential VEGFR-2 inhibitors.

A novel series of 2-acetamide-5-phenylthio-1,3,4-thiadiazol derivatives containing a phenyl urea warhead were synthesized and evaluated as antiproliferative agents. The cytotoxic activities of the newly synthesized compounds were evaluated toward three human cancer cell lines, including HT-29, A431, and PC3, as well as normal HDF cells, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The biological results revealed the highest degree of cytotoxic effects for the 4-chloro-containing compound 9e against the A431 cell line. Further assessment by Western blot analysis assay confirmed the induction of apoptosis by compound 9e, with upregulation of Bax and downregulation of Bcl-2 proteins in A431 cancer cells. In addition, compound 9e inhibited the phosphorylation of vascular endothelial growth factor and its receptor (VEGFR-2) in A431 cancer cells while the total level of actin protein was unchanged. These results were confirmed by a three-dimensional cell culture method using the hanging drop technique.

Synthesis, in-vitro evaluation, molecular docking, and kinetic studies of pyridazine-triazole hybrid system as novel α-glucosidase inhibitors.

In this study, we reported the discovery of pyridazine based 1,2,3-triazole derivatives as inhibitors of α-glucosidase. All target compounds exhibited significant inhibitory activities against yeast and rat α-glucosidase enzymes compared to positive control, acarbose. The most potent compound 6j, ethyl 3-(2-(1-(4-nitrobenzyl)-1H-1,2,3-triazol-4-yl)ethyl)-5,6-diphenylpyridazine-4-carboxylate exhibited IC50 values of 58, and 73 µM. Docking studies indicated the responsibility of hydrophobic and hydrogen bonding interactions in the ligand-enzyme complex stability. The in-vitro safety against the normal cell line was observed by toxicity evaluation of the selected compounds.

Design, synthesis, molecular docking study, and antibacterial evaluation of some new fluoroquinolone analogues bearing a quinazolinone moiety.

BACKGROUND: Increasing bacterial resistance to quinolones is concerning. Hence, the development of novel quinolones by chemical modifications to overcome quinolone resistance is an attractive perspective in this context. OBJECTIVE: In this study, it is aimed to design and synthesize a novel series of functionalized fluoroquinolones using ciprofloxacin and sarafloxacin cores by hybridization of quinazolinone derivatives. This objective was tested by a comprehensive set of in vitro antibacterial assays in addition to SAR (structure-activity relationship) characterisation studies. METHODS: A nucleophilic reaction of ciprofloxacin and sarafloxacin with 2-(chloromethyl)quinazolin-4(3H)-one in the presence of NaHCO3 in dimethylformamide (DMF) was performed to obtain the desired compounds 5a-j. Novel compounds were characterised by 1H, 13C- NMR and IR spectroscopy, MS and elemental analysis. In silico pharmacokinetics prediction assays and molecular docking studies were performed to explore the binding characteristics and interactions. Antibacterial activities of the novel compounds were evaluated by Broth microdilution, well diffusion and disc diffusion assays against three gram-positive (Methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus aureus and Enterococcus faecalis) and three gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli). RESULTS: The compounds exhibited moderate to good activities against gram-positive bacteria and weak to moderate activities against gram-negative bacteria. Amongst all ciprofloxacin-derivatives, compound 5d was the most potent agent with high antibacterial activity against gram-positive bacteria, including MRSA and S. aureus ((minimum inhibitory concentration (MIC) = 16 nM for both), that is 60 times more potent than ciprofloxacin as parent drug. Compound 5i from sarafloxacin-derivatives was the most potent compound against MRSA and S. aureus (MIC = 0.125 µM). Well diffusion and disk diffusion assay results demonstrated confirmatory outcomes for the quantitative broth microdilution assay. Molecular docking study results were in accordance with the results of antibacterial activity assays. CONCLUSION: The results of the current study demonstrated that the novel ciprofloxacin and sarafloxacin derivatives synthesized here have promising antibacterial activities. Particularly, compounds 5d and 5i have potential for wider antibacterial applications following further analysis.

Design and synthesis of novel pyridazine N-aryl acetamides: In-vitro evaluation of α-glucosidase inhibition, docking, and kinetic studies.

We herein applied the four step-synthetic route to prepare the pyridazine core attached to the various N-aryl acetamides. By this approach, a new series of pyridazine-based compounds were synthesized, characterized and evaluated for their activities against α-glucosidase enzyme. In-vitro α-glucosidase assay established that twelve compounds are more potent than acarbose. Compound 7a inhibited α-glucosidase with the IC50 value of 70.1 µM. The most potent compounds showed no cytotoxicity against HDF cell line. Molecular docking and kinetic studies were performed to determine the modes of interaction and inhibition, respectively.

A review on progression of epidermal growth factor receptor (EGFR) inhibitors as an efficient approach in cancer targeted therapy.

The identification of molecular agents inhibiting specific functions in cancer cells progression is considered as one of the most successful plans in cancer treatment. The epidermal growth factor receptor (EGFR) over-activation is observed in a vast number of cancers, so, targeting EGFR and its downstream signaling cascades are regarded as a rational and valuable approach in cancer therapy. Several synthetic EGFR tyrosine kinase inhibitors (TKIs) have been evaluated in recent years, mostly exhibited clinical efficacy in relevant models and categorized into first, second, third and fourth-generation. However, studies are still ongoing to find more efficient EGFR inhibitors in light of the resistance to the current inhibitors. In this review, the importance of targeting EGFR signaling pathway in cancer therapy and related epigenetic mutations are highlighted. The recent advances on the discovery and development of different EGFR inhibitors and the use of various therapeutic strategies such as multi-targeting agents and combination therapies have also been reviewed.

6-Cinnamoyl-4-arylaminothienopyrimidines as highly potent cytotoxic agents: Design, synthesis and structure-activity relationship studies.

In this paper, we described the synthesis and cytotoxic activities of two new series of thieno[2,3-d]pyrimidine and thieno[3,2-d] pyrimidine derivatives. Most of the synthesized compounds had significant antiproliferative activities against PC3, MDA-MB-231, A549, and HeLa cell lines in comparison to the reference drug, erlotinib. Compounds N-(4-((3,5-dichlorophenyl)amino)thieno[2,3-d]pyrimidin-6-yl)cinnamamide 8e and (E)-N-(4-((3,4-dichlorophenyl)amino)thieno[2,3-d]pyrimidin-6-yl)-3-(4-methoxyphenyl)acrylamide 8g with IC50 values of 4 nM and 33 nM, respectively, against HeLa cell line were chosen for further studies. The apoptosis induced activity and cell cycle arrest were determined and the results provided evidence that these compounds induced cell death via apoptosis and arrested cell growth in sub-G1 phase. In addition, western blot analysis manifested the promising result of suppressing the EGFR signaling pathway (p-EGFR/p-ERK1/2). The docking studies appreciated the considerable potency of compound 8e based on hydrogen and covalent binding interactions. Eventually, in silico pharmacokinetic prediction indicated the acceptable bioavailability of all final compounds.