Synthesis of novel conjugated benzofuran-triazine derivatives: Antimicrobial and in-silico molecular docking studies.

Two new developments of antibacterial agents, a series of benzofuran-triazine based compounds (8a-8h) were designed and synthesized. The derivatives were prepared through conventional chemical reactions and structurally characterized with FT-IR, 1H and 13C NMR techniques. The antibacterial activity of the synthesized derivatives was assessed against gram-positive bacterial strains (Bacillus subtilis, and Staphylococcus aureus) and gram-negative bacterial strains (Salmonella entritidis and Escherichia coli). Compound 8e, with the MIC value of 125-32 µg/µl against all the examined strains of bacteria, was the most active antibacterial compound. The synthesized derivatives were also studied for docking to the binding sites of dihydrofolate reductase (DHFR) receptor which has a key role in drug resistance associated with bacterial infections. The synthesized compounds showed good interaction with the targets through hydrogen bonding and hydrophobic interactions. According to antibacterial and docking studies, compound 8e could be introduced as a candidate for development of antibacterial compounds.

Design, synthesis, docking, and antidepressant activity evaluation of isatin derivatives bearing Schiff bases.

Objectives: Depression is a prevalent psychiatric disorder. Treatment of depression is still a challenge due to the lack of response of some patients to a variety of available medications and side effects. Isatin is an interesting molecule with diversified biological effects. It also participates in many synthetic reactions, as a precursor molecule. In this study, a new series of N-alkyl and N-benzyl isatin derivatives bearing Schiff bases were synthesized and screened for antidepressant activities in mice. Materials and Methods: The synthesis was initiated by N-alkylation and N-benzylation of isatin by an alkylation reaction to give N-substituted isatins. 2-(Benzyloxy) benzohydrazide derivatives were synthesized by treating methyl2-hydroxybenzoate with benzyl bromide or 4-chlorobenzyl bromide which was followed by a reaction with hydrazine hydrate to provide acid hydrazide derivatives. The final compounds were obtained by condensation of N-substituted isatins with 2-(benzyloxy) benzohydrazide derivatives as Shiff-base products. Compounds were evaluated for antidepressant activities in mice by the locomotor activity, marble burying test, and forced swimming test. Monoamine oxidase-A (MAO-A) enzyme has been used for molecular docking studies. Results: Compounds 8b and 8e in both doses, and 8 c in the lower dose, reduced immobility time during the forced swimming test relative to the control group. All preparations reduced the number of marbles buried compared with the control group. The highest docking score was -11.01 kcal/mol for compound 8e. Conclusion: N-Benzylated-isatin (8b, 8e) and N- acetic acid ethyl ester -isatin derivatives (8c) showed more effective antidepressant activity compared with N-phenyl acetamide isatin derivatives. Docking results relatively confirm the pharmacological results.

Design and synthesis of some novel triazine-tyrosine hybrids as potential agents for the treatment of multiple sclerosis.

Background and purpose: One of the most noteworthy methods to slow down multiple sclerosis (MS) progress is a decrease of lymphocyte cells via S1P1 receptor modulating. Here, a series of S1P1 receptor modulators were designed and investigated for their ability to decrease lymphocytes in a rat model. Experimental approach: Molecular docking was performed to compare the binding mode of desired compounds 5a-f with fingolimod to the active site of the S1P1 receptor, theoretically. To prepare desired compounds, 5a-f, cyanuric chloride was reacted with different amines, a-f, which then converted to 4a-f compounds through reaction with N-boc-Tyr-OMe ester. Finally, deprotection of the carboxyl and amino groups was carried out to obtain 5a-f as final products. Lymphocyte counting in the rat model was carried out using flow cytometry to evaluate the efficacy of the suggested compounds. Findings / Results: All compounds exhibited lower binding energy than fingolimod. Compound 5e with ΔG= -8.10 kcal/mol was the best compound. The structure of the compounds was confirmed spectroscopically. The in vivo study proved that compounds 5b and 5a decreased the lymphocytes level at 0.3 and 3 mg/kg, respectively. Conclusion and implications: The desired compounds were well fitted in the receptor active site following molecular docking studies. The results of lymphocyte count revealed that compounds 5a and 5b with propyl and ethyl substitutes showed the maximum activity in vivo. Finally, the results of the present project can be used for forthcoming investigations towards the design and synthesis of novel potential agents for MS treatment.

Preparation, physicochemical, and retinal anti-angiogenic evaluation of poloxamer hydrogel containing dexamethasone/avastin-loaded chitosan-N-acetyl-L-cysteine nanoparticles.

This study was meant to describe a Poloxamer hydrogel combining Chitosan-N-acetyl-L-cysteine (CNAC) nanoparticles to increase loading and sustained intravitreal administration of Avastin macromolecule. To increase the drug's efficacy and reduce the interfacial fluid pressure in a formulation, dexamethasone was used. To do so, CNAC was synthesized. Then, Avastin- loaded CNAC nanoparticles were prepared and optimized. The resulting hydrogel's sol-gel transition time and viscosity were determined using poloxamer and hydroxypropylmethylcellulose (HPMC). In vitro and in vivo investigations of Avastin-loaded CNAC nanoparticles and hydrogel comprising dexamethasone/Avastin-loaded CNAC nanoparticles were determined. In vitro, the drug release profile of optimized hydrogel containing Avastin-loaded CNAC nanoparticles was sustained and controlled over 256 h. The obtained results point to poloxamer/HPMC (18 %/0.5 %) as the best formulations for this hydrogel to develop a sol-gel transition. About 97 % of dexamethasone was released from the hydrogel within 18 h. In vivo results indicated that the optimized formulation compared with free Avastin could improve Diabetic retinopathy (DR). Consequently, we infer that this new drug delivery method may enhance Avastin intravitreal administration, lowering the frequency, danger, and expense of heavy intravitreal injections and resulting in improved treatment of posterior eye segment neovascularization and concomitant vitreoretinal disorders.

Some novel hybrid quinazoline-based heterocycles as potent cytotoxic agents.

BACKGROUND AND PURPOSE: In this study, some new cytotoxic hybrid structures were synthesized by combining pyrazolinone and imidazolinone rings with quinazoline pharmacophores. EXPERIMENTAL APPROACH: The benzoxazinone, pyrazolo-quinazoline fused ring, and imidazolinone anchored quinazoline derivatives were synthesized by simple ring-opening, ring expansion, and ring closure strategies from oxazolones. The molecular docking studies of the final derivatives were accomplished on the epidermal growth factor receptor enzyme. The cytotoxic effect of the final compounds on the MCF-7 cell line was evaluated by MTT assay. FINDINGS/RESULTS: The docking results confirmed the optimized electrostatic, H-bonding, and hydrophobic interactions of structures with the key residues of the active site (ΔGbin< -9Kcal/mol). The derivatives have been obtained in good yield and purity, and their structures were confirmed by different methods (FT-IR, 1H-NMR, 13C-NMR, and CHNS analysis). The IC50s of all final derivatives against the MCF-7 cell line were lower than 10 µM, and between all, the IXa from pyrazolo-quinazolinone class (IC50: 6.43 µM) with chlorine substitute was the most potent. Furthermore, all derivatives showed negligible cytotoxicity on HUVEC normal cell line which would be a great achievement for a novel cytotoxic agent. CONCLUSION AND IMPLICATIONS: Based on the obtained results, pyrazolo[1,5-c] quinazolin-2-one series were more cytotoxic than imidazolinone methyl quinazoline-4(3H)-ones against MCF-7 cells. Chlorine substitute in the para position of the aromatic ring improved the cytotoxicity effect in both classes. It could be related to the polarizability of a chlorine atom and making better intermolecular interactions. Further pre-clinical evaluations are required for the promising synthesized cytotoxic compounds.

Synthesis and cytotoxic activity evaluation of some new 1, 3, 4-oxadiazole, 1, 3, 4-thiadiazole and 1, 2, 4- triazole derivatives attached to phthalimide.

BACKGROUND AND PURPOSE: In the last few decades, nitrogen-rich heterocyclic compounds such as 1, 3, 4-thiadiazoles, 1, 2, 4-triazoles and 1, 3, 4-oxadiazoles have received considerable attention because of their notable biological properties, especially cytotoxic effects. The small molecules of mentioned azole derivatives revealed very intensive antitumor activity. In addition, phthalimide-thiadiazole and naphthalimide-triazole hybrid derivatives have shown remarkable cytotoxic effects. According to these observations, some of the hybrid derivatives containing the phthalimide-five-membered azoles were prepared in three steps in this research. EXPERIMENTAL APPROACH: The thiol group of azoles was treated with ethyl chloroacetate which was followed by a reaction with hydrazine hydrate to provide acid hydrazide derivatives. Subsequently, the corresponding acid hydrazides were utilized to prepare the final derivatives through the reaction with phthalic anhydride. Cytotoxic activity of final compounds was evaluated against MCF-7 and HeLa cell lines using MTT assay. FINDINGS/RESULTS: Compound 3d containing two phthalimide moieties in its structure showed a significant improvement in cytotoxic activity with an IC50 value of 29 µM against HeLa cell line. Compounds 3a-3c showed less cytotoxic effects against both cell lines. CONCLUSION AND IMPLICATIONS: The combination of the thiadiazole nucleus with two phthalimide structures increased the cytotoxic activity against the HeLa cell line. This increase in cytotoxic activity is probably due to its being more lipophilic characteristic and interaction of this derivative with the biological targets of two directions.

Design, synthesis, biological evaluation, and molecular modeling studies of pyrazole-benzofuran hybrids as new α-glucosidase inhibitor.

In this work, new derivatives of biphenyl pyrazole-benzofuran hybrids were designed, synthesized and evaluated in vitro through enzymatic assay for inhibitory effect against α-glucosidase activity. Newly identified inhibitors were found to be four to eighteen folds more active with IC50 values in the range of 40.6 ± 0.2-164.3 ± 1.8 µM, as compared to the standard drug acarbose (IC50 = 750.0 ± 10.0 µM). Limited Structure-activity relationship was established. A kinetic binding study indicated that most active compound 8e acted as the competitive inhibitors of α-glucosidase with Ki = 38 µM. Molecular docking has also been performed to find the interaction modes responsible for the desired inhibitory activity. As expected, all pharmacophoric features, used in the design of the hybrid, are involved in the interaction with the active site of the enzyme. In addition, molecular dynamic simulations showed compound 8e oriented vertically into the active site from mouth to the bottom and stabilized the enzyme domains by interacting with the interface of domain A and domain B and the back side of the active site while acarbose formed non-binding interaction with the residue belong to the domain A of the enzyme.

Design, synthesis, and bio-evaluation of new isoindoline-1,3-dione derivatives as possible inhibitors of acetylcholinesterase.

BACKGROUND AND PURPOSE: Alzheimer's disease is considered one of the lead causes of elderly death around the world. A significant decrease in acetylcholine level in the brain is common in most patients with Alzheimer's disease, therefore acetylcholinesterase (AChE) inhibitors such as donepezil and rivastigmine are widely used for patients with limited therapeutic results and major side effects. EXPERIMENTAL APPROACH: A series of isoindoline-1,3-dione -N-benzyl pyridinium hybrids were designed, synthesized and evaluated as anti-Alzheimer agents with cholinesterase inhibitory activities. The structure of the compounds were confirmed by various methods of analysis such as HNMR, CNMR, and FT-IR. Molecular modeling studies were also performed to identify the possible interactions between neprilysin and synthesized compounds. FINDINGS/RESULTS: The biological screening results indicated that all synthesized compounds displayed potent inhibitory activity with IC50 values ranging from 2.1 to 7.4 µM. Among synthesized compounds, para-fluoro substituted compounds 7a and 7f exhibited the highest inhibitory potency against AChE (IC50 = 2.1 µM). Molecular modeling studies indicated that the most potent compounds were able to interact with both catalytic and peripheral active sites of the enzyme. Also, some of the most potent compounds (7a, 7c, and 7f) demonstrated a neuroprotective effect against H2O2-induced cell death in PC12 neurons. CONCLUSION AND IMPLICATIONS: The synthesized compounds demonstrated moderate to good AChE inhibitory effect with results higher than rivastigmine.

Boron phenyl alanine targeted ionic liquid decorated chitosan nanoparticles for mitoxantrone delivery to glioma cell line.

Nanotechnology has revolutionized drug delivery in cancer treatment. In this study, novel efficient pH-responsive boron phenylalanine (BPA) targeted nanoparticles (NPs) based on ionic liquid modified chitosan have been introduced for selective mitoxantrone (MTO) delivery to the U87MG glioma cells. Urocanic acid (UA) and imidazolium (Im) based ionic liquids were used for structural modification simultaneously. The NPs were prepared by ionic gelation and fully characterized; the pH-responding and swelling index of NPs were studied carefully. The drug release was studied at a pH of 5.5 in comparison to the neutral state. Also, the cytotoxicity of loaded NPs was evaluated on U87MG glial cells, and cellular uptake was studied. The NPs were smaller than 250 nm, with a spherical pattern and acceptable uniformity with a zeta potential around +20 mV. The loading efficacy was about 85%, and most of the loaded MTO released at a pH of 5.5 after 48 h with a swelling-controlled mechanism. The NPs showed a relatively lower IC50 than the free MTO, and the BPA-targeted NPs have lower IC50 and better cellular uptake than non-targeted NPs in U87MG cells. More studies on this promising formula are on the way, and the results will be published soon.

Design and synthesis of novel quinazolinone-pyrazole derivatives as potential α-glucosidase inhibitors: Structure-activity relationship, molecular modeling and kinetic study.

In this study, a new series of quinazolinone-pyrazole hybrids were designed, synthesized and screened for their α-glucosidase inhibitory activity. The results of the in vitro screening indicated that all the molecular hybrids exhibited more inhibitory activity (IC50 values ranging from 60.5 ± 0.3 µM-186.6 ± 20 µM) in comparison to standard acarbose (IC50 = 750.0 ± 10.0 µM). Limited structure-activity relationship suggested that the variation in the inhibitory activities of the compounds affected by different substitutions on phenyl rings of diphenyl pyrazole moiety. The enzyme kinetic studies of the most potent compound 9i revealed that it inhibited α-glucosidase in a competitive mode with a Ki of 56 µM. Molecular docking study was performed to predict the putative binding interaction. As expected, all pharmacophoric moieties used in the initial structure design playing a pivotal role in the interaction with the binding site of the enzyme. In addition, by performing molecular dynamic investigation and MM-GBSA calculation, we investigated the difference in structural perturbation and dynamic behavior that is observed over α-glycosidase in complex with the most active compound and acarbose relative to unbound α-glycosidase enzyme.

Synthesis, antioxidant activity, and density functional theory study of some novel 4-[(benzo[d]thiazol-2-ylimino)methyl]phenol derivatives: a comparative approach for the explanation of their radical scavenging activities.

BACKGROUND AND PURPOSE: Radicals produced by Fenton and Haber-Weiss reactions play detrimental roles in our body. Some oxidized proteins as toxic configurations are identified in amyloid-ß deposits. These deposits mostly occur in conditions, such as Alzheimer's disease. Here, we report the synthesis, evaluation of the antioxidant activity, and implementation of density functional theory (DFT) calculations of some4- [(benzo[d]thiazol-2-ylimino) methyl]phenol derivatives. The aim of this study was to provide a comparative theoretical-experimental approach to explain the antioxidant activities of the compounds. EXPERIMENTAL APPROACH: Compounds were synthesized by the reaction between para hydroxybenzaldehyde and aminobenzothiazole derivatives. The scavenging activity of the compounds was evaluated. Various electronic and energetic descriptors such as high occupied molecular orbital and low unoccupied molecular orbital energy gaps, bonding dissociation enthalpy of OH bond, ionization potential, electron affinity, hardness, softness, and spin density of the radical and neutral species were calculated. DFT calculations with B3LYP hybrid functional and 6-311++ G** basis set in the polarizable continuum model were utilized to obtain these descriptors. FINDINGS/RESULTS: Ascorbic acid showed the best DPPH scavenging activity. However, 4d and 4c showed promising antioxidant activity. The values of EHOMO for 4c and 4d were closer to zero, thus, they showed the best scavenging activities. The computational results were in accordance with the experimental ones. The energetic descriptors indicated that the sequential proton loss-electron transfer mechanism is preferred over other mechanisms. CONCLUSION AND IMPLICATION: Antioxidant activity of 4-[(Benzo[d]thiazol-2-ylimino) methyl]phenol derivatives confirmed by experimental and theoretical documents proves them as novel antioxidants against amyloid-ß based disease.

Biotin-Targeted Nanomicellar Formulation of an Anderson-Type Polyoxomolybdate: Synthesis and In Vitro Cytotoxicity Evaluations.

This study is aimed at developing a micellar carrier for an Anderson-type manganese polyoxomolybdate (TRIS-MnPOMo) to improve the potency and reduce the general toxicity. The biotin-targeted stearic acid-polyethylene glycol (SPB) polymeric conjugate was selected for the first time as a micelle-forming basis for the delivery of TRIS-MnPOMo to breast cancer cells. The cytotoxicity of TRIS-MnPOMo and its nanomicellar form (TRIS-MnPOMo@SPB) was evaluated against MCF-7, MDA-MB-231 (breast cancer cell lines), and HUVEC (normal cell line) in vitro using the MTT assay. The quantity of cellular uptake and apoptosis level were studied properly using standard methods. The hydrodynamic size, zeta potential, and polydispersity index of the prepared micelles were 140 nm, -15.6 mV, and 0.16, respectively. The critical micelle concentration was about 30 µg/mL, which supports the colloidal stability of the micellar dispersion. The entrapment efficiency was interestingly high (about 82%), and a pH-responsive release of TRIS-MnPOMo was successfully achieved. The micellar form showed better cytotoxicity than the free TRIS-MnPOMo on cancer cells without any significant heme and normal cell toxicity. Biotin-targeted nanomicelles internalized into the MDA-MB-231 cells interestingly better than nontargeted micelles and TRIS-MnPOMo, most probably via the endocytosis pathway. Furthermore, at the same concentration, micelles remarkably increased the level of induced apoptosis in MDA-MB-231 cells. In conclusion, TRIS-MnPOMo@SPB could profoundly improve potency, safety, and cellular uptake; these results are promising for further evaluations in vivo.

Identification of New Hsp90 Inhibitors: Structure Based Virtual Screening, Molecular Dynamic Simulation, Synthesis and Biological Evaluation.

BACKGROUND: Heat shock protein90 (Hsp90) is overexpressed in tumor cells, thus the inhibition of the Hsp90 ATPase activity would be a meaningfully effective strategy in cancer therapy. OBJECTIVE: The present work was aimed at four steps: designing new Hsp90 inhibitors as anti-cancer by a virtual screening study; synthesize designed compounds; biological evaluation of them and finally molecular dynamic (MD) simulations of best compounds. METHODS: A virtual screening study was performed on a library (100 compounds) of the ZINC database with benzimidazole scaffold; then an extracted compound and two derivatives were synthesized. The anti-proliferative and ATPase inhibitory activities of these compounds were evaluated by MTT and ATPase inhibition assays, respectively. The western blot analysis was performed to the evaluation of the expression level of Hsp70 and Her2 proteins. Finally, 200 ns molecular dynamic simulation was carried out to confirm the stability of the strongest synthesized compound in Hsp90 active site. RESULTS: ZINC00173501 compound with an aminobenzimidazole scaffold was chosen by the virtual screening study. ZINC00173501 compound and two of its derivatives were synthesized. ATPase inhibitory activity of three synthesized compounds shown that ZINC00173501 compound was the most potent inhibitor (IC50= 8.6 µM) with the anti-proliferative activity 14.41 µM, 19.07 µM and more than 100 µM against MCF-7, HeLa and HUVEC cell lines, respectively. The high level of Hsp70 expression and low level of Her2 expression confirmed ZINC00173501 as an Hsp90 inhibitor. Finally, molecular dynamics simulation showed that ZINC00173501 was stable in Hsp90 active site during 200 ns simulation. CONCLUSION: The biological evaluation results show that 2-aminobenzimidazole scaffold could be suggested as a lead for inhibition of Hsp90.

Boron phenyl alanine targeted chitosan-PNIPAAm core-shell thermo-responsive nanoparticles: boosting drug delivery to glioblastoma in BNCT.

Boron neutron capture therapy (BNCT) is one of the best treatment modalities for glioblastoma multiform that could selectively kill the tumor cells. To be successful in BNCT, it is crucial to have enough 10B in the tumor. l-boron phenylalanine (l-BPA) targeted thermo-responsive core-shell nanoparticles (NPs) of chitosan-poly(N-isopropylacrylamide) (PNIPAAm) were our idea for endocytosis via sialic acid receptors, and selective delivery of 10B to glial cells. Methotrexate (MTX) was chosen as a model drug for evaluating the efficacy of NPs in tumor cells, and BPA was selected for BNCT purposes. The polymeric conjugates were synthesized and the chemical structures were approved by spectroscopic methods (FTIR, 1H NMR, and 11B NMR). Cargos were loaded efficiently (>95%) in the prepared NPs, and the release profile of MTX and BPA was studied around the lower critical solution temperature (LCST; about 39 °C). The loaded drugs were released quantitatively at the LCST, while almost no drug was released at 37 °C. The prepared NPs did not show considerable hemolysis ratio (<2%) and were still safe when loaded BPA, on U87MG cells. The MTX loaded NPs showed lower IC50 (30.78 µg/mL) than the free MTX (37.03 µg/mL) in MTT assay, and targeted NPs had the lowest IC50s in U87MG cell lines (27.35 µg/mL). Targeted BPA@CSSU-PNI NPs were uptaken better than the non-targeted ones by U87MG cells, and CR-39 assay showed the boron content efficiency for further applications in BNCT. This study's results introduce novel targeted thermo-responsive NPs for treating glioblastoma using BNCT.

Design and synthesis of novel pyrazole-phenyl semicarbazone derivatives as potential α-glucosidase inhibitor: Kinetics and molecular dynamics simulation study.

A series of novel pyrazole-phenyl semicarbazone derivatives were designed, synthesized, and screened for in vitro α-glucosidase inhibitory activity. Given the importance of hydrogen bonding in promoting the α-glucosidase inhibitory activity, pharmacophore modification was established. The docking results rationalized the idea of the design. All newly synthesized compounds exhibited excellent in vitro yeast α-glucosidase inhibition (IC50 values in the range of 65.1-695.0 µM) even much more potent than standard drug acarbose (IC50 = 750.0 µM). Among them, compounds 8o displayed the most potent α-glucosidase inhibitory activity (IC50 = 65.1 ± 0.3 µM). Kinetic study of compound 8o revealed that it inhibited α-glucosidase in a competitive mode (Ki = 87.0 µM). Limited SAR suggested that electronic properties of substitutions have little effect on inhibitory potential of compounds. Cytotoxic studies demonstrated that the active compounds (8o, 8k, 8p, 8l, 8i, and 8a) compounds are also non-cytotoxic. The binding modes of the most potent compounds 8o, 8k, 8p, 8l and 8i was studied through in silico docking studies. Molecular dynamic simulations have been performed in order to explain the dynamic behavior and structural changes of the systems by the calculation of the root mean square deviation (RMSD) and root mean square fluctuation (RMSF).

Monastrol derivatives: in silico and in vitro cytotoxicity assessments.

BACKGROUND AND PURPOSE: Cancer is the leading cause of death in today's world, therefore the efforts to achieve anticancer drugs with higher potency and fewer side effects have always been conducted by researchers in the field of pharmaceutical chemistry.Monastrol, a cytotoxic small molecule, from dihydropyrimidinone scaffold, is an inhibitor of the kinesin-5 protein. So, efforts to identify more derivatives of this molecule have been of interest. EXPERIMENTAL APPROACH: Some of monastrol's analogs as Eg5 inhibitors with different substitution patterns were analyzed, synthesized, and their cytotoxic effects were evaluated on MCF-7 and HeLa cancerous cells in vitro using the MTT assay. The structure-activity relationship (SAR) was studied in silico by molecular docking. FINDINGS / RESULTS: Among all proposed structures, in ducking study, those with hydrophobic moieties on the C2-N3 region, those with a hydroxyl group on the phenyl on C4 position, and those with a carboxylic group on C5 were the best candidates. In vitro studies, on the other side, emphasized that monastrol still was the most potent derivative. Another finding was the more moderate activity of synthesized compounds on the HeLa cell compared to the MCF-7 cell line. During different challenges for substitution at 5-position, some earlier reports around the dihydropyrimidinone reactions were questioned. It seems that the change at the position 5 is not merely accessible, as earlier reports claimed. Also, we could not achieve any better cell cytotoxicity by the larger group in the thiourea region or position 5; nonetheless, it seems that the introduction of a methylene group at this position could be beneficial. CONCLUSION AND IMPLICATIONS: The initial results of this study were valuable in terms of design and synthesis and will be useful for future investigations.

Synthesis, cytotoxic evaluation, and molecular docking studies of some new 1, 3, 4-oxadiazole-based compounds.

BACKGROUND AND PURPOSE: Oxadiazole-derived compounds have been shown to have a wide range of pharmacological activities. 2, 5-Disubstituted 1, 3, 4-oxadiazole derivatives have occupied a specific place in the design of anti-proliferative agents. In the present work a series of 2, 5-disubstituted 1, 3, 4-oxadiazoles derivatives containing amide group has been synthesized via a two-step reaction. EXPERIMENTAL APPROACH: A mixture of substituted carboxylic acid derivatives, semicarbazide, and phosphorus oxychloride in reflux condition yielded 2-amino-5-aryl-1, 3, 4-oxadiazole derivatives. Acylation of the amino group of the resultant oxadiazole with 6-chloronicotinoyl chloride in dry tetrahydrofuran/pyridine afforded the final products. The synthesized molecules were docked in the active sites of the epidermal growth factor receptor tyrosine kinase domain (PDB: 1M17) crystal structure to study the possible interactions with the active site. Cytotoxic activities of final products against HeLa and MCF-7 cells were also assessed by MTT assay. FINDINGS/RESULTS: Compounds IIb, IIc, and IIe had a considerable cytotoxic activity with IC50 values of 19.9, 35, and 25.1 µM, respectively against HeLa cells. The highest docking score was -7.89 kcal/mol for compound IIe. CONCLUSION AND IMPLICATIONS: Compound IIe exhibited remarkable cytotoxic activity against the two tested cell lines particularly HeLa cells which was in accordance with the in silico ΔG bind result but further evaluations are necessary to prove these findings.

Targeted Nanoparticles for Co-delivery of 5-FU and Nitroxoline, a Cathepsin B Inhibitor, in HepG2 Cells of Hepatocellular Carcinoma.

BACKGROUND: The first choice of treatment in Hepatocellular Carcinoma (HCC) is 5-fluorouracil (5-FU). Nitroxoline (NIT), a potent inhibitor of Cathepsin B, impairs tumor progression by decreased extracellular matrix degradation. The objective of the current project was designed to target nanoparticles for co-delivery of 5-FU and NIT in order to enhance the 5-FU cytotoxic effects and reduce the metastatic properties of HepG2 cells. METHODS: 5-FU and NIT were loaded in chitosan-chondroitin nanoparticles. To target the CD44 receptors of HepG2 cells, Hyaluronic Acid (HA) was conjugated to the chondroitin by adipic acid dihydrazide and the conjugation was confirmed by FTIR and 1HNMR. After physicochemical characterization and optimization of the processing variables, MTT assay was done on HepG2 and NIH3T3 cell lines to determine the cytotoxic properties of HA targeted nanoparticles. Migration of the cells was studied to compare the co-delivery of the drugs with each drug alone. RESULTS: The optimized nanoparticles showed the particle size of 244.7±16.3nm, PDI of 0.30±0.03, drug entrapment efficiency of 46.3±5.0% for 5-FU and 75.1±0.9% for NIT. The drug release efficiency up to 8 hours was about 37.6±0.9% for 5-FU and 62.9±0.7% for NIT. The co-delivery of 5-FU and NIT in targeted nanoparticles showed significantly more cytotoxicity than the mixture of the two free drugs, non-targeted nanoparticles or each drug alone and reduced the IC50 value of 5-FU from 3.31±0.65µg/ml to 0.17±0.03µg/ml and the migration of HepG2 cells was also reduced to five-fold. CONCLUSION: Co-delivery of 5-FU and NIT by HA targeted chitosan-chondroitin nanoparticles may be promising in HCC.

Synthesis and cytotoxic evaluation of some quinazolinone- 5-(4-chlorophenyl) 1, 3, 4-oxadiazole conjugates.

1, 3, 4- Oxadiazoles and quinazolinones are privileged structures with extensive biological activities. On account of reported anticancer activity of them, in this study, a multi-step reaction procedure has been developed for the synthesis of some quinazolinone-1, 3, 4-oxadiazole derivatives. Reaction of the synthesized 3-amino-4(3H) quinazolinone derivatives with chloroacetyl chloride in the presence of dichloromethane/triethylamine yielded 2-chloro -N-(4-oxo-2-quinazolin3 (3H)-yl) acetamide derivatives as intermediate. Treatment of the resultants with 5- (4-chlorophenyl) 1, 3, 4-oxadiazole-2-thiol in dry acetone and potassium carbonate gave coupled derivatives of quinazolinone-1, 3, 4-oxadiazole. The cytotoxic effect of final compounds was tested against MCF-7 and HeLa cell lines using MTT assay. Compound 2-(5-(4-chlorophenyl)-1,3,4-oxadiazol-2-ylthio) N-(4-oxo-2-propylquinazolin)3(4H)acatamide 6a exhibited remarkable cytotoxic activity at 10 and 100 µM against HeLa cell line. The alteration of substituents on C2 of quinazolinone ring revealed that the introduction of propyl moeity improved cytotoxic activity against HeLa cell line.

Synthesis and cytotoxic evaluation of some derivatives of triazole-quinazolinone hybrids.

Triazoles and quinazolinones are important heterocyclic structures with diverse biological properties including cytotoxic, antibacterial, antifungal and anticonvulsant activities. Due to valuable cytotoxic effects of both triazole and quinazoline derivatives, in this study a series of quinazolinone-triazole hybrids were synthesized in a multiple-step reaction procedure. 3-Amino-quinazolinone derivatives were treated with chloroacetyl chloride in the presence of dichloromethane/triethylamine to afford 2-chloro -N-(4-oxo-2- quinazolin3 (3H)-yl) acetamide derivatives. The reaction of resultants with 4-mehyl-4-H-1, 2, 4-triazole-3- thiol in dry acetone and potassium carbonate led to the formation of final products. Synthesized compounds were evaluated for their cytotoxic effects against MCF-7 and Hela cell lines using MTT colorimetric assay. Amongst tested compounds, 6a showed the highest cytotoxic activity against MCF7 cell line at all tested concentrations while compounds 6b and 6c indicated mild cytotoxic effects against Hela cell line at highest tested concentration reducing cell viability about 40%. The IC50 values of tested compounds revealed that the MCF-7 is more susceptible to the compound 6a.