New Pyrazole-Clubbed Pyrimidine or Pyrazoline Hybrids as Anti-Methicillin-Resistant Staphylococcus aureus Agents: Design, Synthesis, In Vitro and In Vivo Evaluation, and Molecular Modeling Simulation.

Two hybrid series of pyrazole-clubbed pyrimidines 5a-c and pyrazole-clubbed pyrazoline compounds 6a,b and 7 were designed as attractive scaffolds to be investigated in vitro and in vivo for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. From the results of the in vitro antibacterial screening, compound 5c showed excellent activity (minimal inhibitory concentration, MIC = 521 µM) when compared with that of the reference antibiotic levofloxacin (MIC = 346 µM). The inhibition of the target dihydrofolate reductase (DHFR) enzyme by compounds 4 and 5a-c (IC50 = 5.00 ± 0.23, 4.20 ± 0.20, 4.10 ± 0.19, and 4.00 ± 0.18 µM, respectively) was found to be better than the reference drug trimethoprim (IC50 = 5.54 ± 0.28 µM). Molecular modeling simulation results have justified the order of activity of all the newly synthesized compounds as DHFR enzyme inhibitors, and compound 5c exhibited the best binding profile (-13.6169386 kcal/mol). Hence, the most potent inhibitor of the DHFR enzyme, 5c, was chosen to be evaluated in vivo for its activity in treating MRSA-induced keratitis in rats and that, in turn, significantly (P < 0.0001) reduced infection in rats when compared to MRSA-treated group results.

Synthesis and Molecular Docking Study of New Thiazole Derivatives as Potential Tubulin Polymerization Inhibitors.

A new series of 2,4-disubstituted thiazole derivatives containing 4-(3,4,5-trimethoxyphenyl) moiety was synthesized and evaluated for their potential anticancer activity as tubulin polymerization inhibitors. All designed compounds were screened for cytotoxic activity against four human cancer cell lines, namely, HepG2, MCF-7, HCT116, and HeLa, using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, with combretastatin A-4 as a reference drug. Compounds 5c, 6d, 7c, 8, and 9a,b showed superior activity against the tested cell lines, with IC50 values ranging from 3.35 ± 0.2 to 18.69 ± 0.9 µM. Further investigation for the most active cytotoxic agents as tubulin polymerization inhibitors was also performed in order to explore the mechanism of their antiproliferative activity. The obtained results suggested that compounds 5c, 7c, and 9a remarkably inhibit tubulin polymerization, with IC50 values of 2.95 ± 0.18, 2.00 ± 0.12, and 2.38 ± 0.14 µM, respectively, which exceeded that of the reference drug combretastatin A-4 (IC50 2.96 ± 0.18 µM). Molecular docking studies were also conducted to investigate the possible binding interactions between the targeted compounds and the tubulin active site. The interpretation of the results showed clearly that compounds 7c and 9a were identified as the most potent tubulin polymerization inhibitors with promising cytotoxic activity and excellent binding mode in the docking study.

Synthesis and anti-inflammatory activity of sulfonamides and carboxylates incorporating trimellitimides: Dual cyclooxygenase/carbonic anhydrase inhibitory actions.

Trimellitimides 6-21 were prepared and investigated in vivo for anti-inflammatory and ulcerogenic effects and in vitro for cytotoxicity. They were subjected to in vitro cyclooxygenase (COX-1/2) and carbonic anhydrase inhibition protocols. Compounds 6-11 and 18 exhibited anti-inflammatory activities and had median effective doses (ED50) of 34.3-49.8 mg kg-1 and 63.6-86.6% edema inhibition relative to the reference drug celecoxib (ED50: 33.9 mg kg-1 and 85.2% edema inhibition). Compounds 6-11 and 18 were weakly cytotoxic at 10 µM against 59 cell lines compared with the reference standard 5-fluorouracil (5-FU). Compounds 6-11 had optimal selectivity against COX-2. The selectivity index (SI) range was >200-490 and was comparable to that for celecoxib [COX-2 (SI) > 416.7]. In contrast, compounds 12, 13, and 16-18 were nonselective COX inhibitors with a selectivity index range of 0.92-0.25. The carbonic anhydrase inhibition assay showed that sulfonamide incorporating trimellitimides 6-11 inhibited the cytosolic isoforms hCA I and hCA II, and tumor-associated isoform hCA IX. They were relatively more susceptible to inhibition by compounds 8, 9, and 11. The KI ranges were 54.1-81.9 nM for hCA I, 25.9-55.1 nM for hCA II, and 46.0-348.3 nM for hCA IX. © 2018 Elsevier Science. All rights reserved.

Synthesis, anti-inflammatory, analgesic, COX-1/2 inhibition activities and molecular docking study of pyrazoline derivatives.

Design, synthesis and pharmacological activities of a group of 1,3,5-trisubstituted pyrazolines were reported. The chemical structures of the synthesized compounds have been assigned on the basis of IR, MS, (1)H NMR, and (13)C NMR spectral analyses. The synthesized 1,3,5-trisubstituted pyrazoline derivatives were evaluated in vivo for anti-inflammatory, analgesic activities and in vitro for COX-1/2 inhibition assay. Among the tested compounds, derivatives 4h, 6e, 7a, 7e, and 9 showed more potent anti-inflammatory and analgesic activities than the reference drug celecoxib. On the basis of their higher activities in the in vivo studies compared with celecoxib, the five compounds 4h, 6e, 7a, 7e and 9 were selected to test their inhibitory activities against ovine COX-1/2 using an in vitro cyclooxygenase inhibition assay. Docking study of compounds 7a, 7e and 9 into the COX-2 binding site revealed a similar binding mode to SC-558, a selective COX-2 inhibitor.

Synthesis and biological evaluation of new curcumin analogues as antioxidant and antitumor agents: molecular modeling study.

New curcumin analogues have been synthesized and their antioxidant activities were investigated by measuring their free radical scavenging capacities. The in vitro and in vivo antitumor activities of the synthesized compounds on Ehrlich ascites carcinoma (EAC) cell line were evaluated. 4-(4-Chlorophenyl)-2-(5-ethyl-7-(4-methoxybenzylidene)-3-(4-methoxyphenyl)-3,3a,4,5,6,7-hexahydro-2H-pyrazolo[4,3-c] pyridin-2-yl)thiazole 7h showed excellent antineoplastic activity in both in vitro and in vivo studies more than that of tested compounds and reference drug, cisplatin. Different molecular modeling studies were performed, where docking of compound 7h into telomerase active site suggested that it could exert its antitumor potential by telomerase inhibition.

N-(12-Amino-9,10-di-hydro-9,10-ethano-anthracen-11-yl)-4-methyl-benzene-sulfonamide.

The title compound, C23H22N2O2S, crystallizes with the 4-methyl-benzene-sulfonamide entity oriented towards the center of the bridgehead C atoms with a C-N-S-C torsion angle of -61.3 (2)°. The mol-ecule features an intra-molecular N-H⋯N hydrogen bond. Weak C-H⋯O and C-H⋯π inter-actions aid in forming the three-dimensional supra-molecular structure.

4-[(1,3-Dioxoisoindolin-2-yl)meth-yl]benzene-sulfonamide.

The title compound, C15H12N2O4S, is V-shaped with the isoindoline ring system (r.m.s. deviation = 0.006 Å) inclined to the benzene ring by 84.27 (13)°. In the crystal, inversion dimers are formed via pairwise N-H⋯O hydrogen bonds. These dimers associate further into corrugated ribbons, via pairwise N-H⋯O and C-H⋯O hydrogen bonds, propagating along the a-axis direction and lying parallel to (001).

(11R,12S)-16-Amino-tetra-cyclo-[6.6.2.0(2,7).0(9,14)]hexa-deca-2(7),3,5,9(14),10,12-hexaen-15-ol.

In the title compound, C(16)H(15)NO, the dihedral angle between the outer benzene rings is 51.88 (6)°, and each of the central six-membered rings has a boat conformation. The hy-droxy and amino groups are syn, and the hy-droxy H atom forms an intra-molecular O-H⋯N hydrogen bond. In the crystal, mol-ecules assemble via C-H⋯O and C-H⋯π inter-actions, consolidating a three-dimensional architecture.

N-(3-Amino-bicyclo-[2.2.1]heptan-2-yl)-4-methyl-benzene-sulfonamide.

In the title compound, C(14)H(20)N(2)O(2)S, the sulfonamide O atoms lie to one side of the benzene ring and the amino-bicyclo-hepta-nyl to the other side [C(ar)-S-N-C torsion angle = -57.93 (11)°; ar = aromatic]. An intra-molecular N-H⋯N hydrogen bond is formed. In the crystal, a supra-molecular chain is formed along the b axis via N-H⋯O and N-H⋯N hydrogen bonds.

Synthesis and antitumor evaluation of novel cyclic arylsulfonylureas: ADME-T and pharmacophore prediction.

Novel derivatives of 5-(substituted)benzylidene-3-(4-substituted)phenylsulfonylimidazolidine-2,4-diones (3a-r), 1-(4-substituted)phenylsulfonyl-3-(4-substituted)phenylpyrimidine-2,4,6-(1H,3H,5H)-triones (6a-l), and 3-(4-substituted)phenyl-1-(4-substituted)phenylsulfonylquinazoline-2,4(1H,3H)- diones (8a-l) have been synthesized and tested for their antitumor activity against 60 tumor cell lines taken from 9 different organs. The tested compounds have showed good inhibitory effect at the ovarian cancer (IGROV1) cell line. A significant inhibition for (RXF393) renal cancer cells was observed with series 3 compounds, while in the other two series 6 and 8, there was a significant inhibition of ovarian cancer cells (OVCAR-8) and melanoma cells (SK-MEL-2). Interestingly; beside the strong inhibition of compound 3q to IGROV1 and RXF393 cells, a great inhibition (199.62%) for (M14) Melanoma cells was observed at the tested concentration (10 microM). ADME-T and pharmacophore prediction methodology were used to study the antitumor activity of the most active compounds and to identify the structural features required for antitumor activity.

Synthesis and antitumor evaluation of novel diarylsulfonylurea derivatives: molecular modeling applications.

Some new ethyl 2-[3-(4-unsubstituted or 4-substituted phenylsufonyl)ureido]-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxylates 3a-c, 2-[3-(phenylsulfonyl)ureido]-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carbohydrazides 4a-f, 3-phenylsulfonyl-6,7,8,9-tetrahydro-5H-cyclohepta[1',2':4,5]thieno[2,3-d]pyrimidine-2,4(1H,3H)dione 5 and 3-(phenylsulfonyl)-1-[3-(alkylaminocarbonyl or substituted piperazinylcarbonyl)-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-2-yl]ureas 6a-d have been synthesized and tested for their antitumor activity. Among these compounds, 4a, 4c and 4d exhibited a broad spectrum antitumor activity with full panel (MG-MID) median growth inhibition (GI(50)) of 3.5, 4.9 and 4.0muM respectively. In addition, compounds 4c, 4d, 6c and 6d proved to be of moderate selectivity toward colon cancer cell lines with ratios of 3.1, 1.2, 3.6 and 3.0 respectively. Molecular modeling and pharmacophore prediction methods are used to study the antitumor activity of the most active compounds compared with the least active species by means of the molecular mechanic method.

Synthesis and in vitro antioxidant activity of some new fused pyridine analogs.

A new series of pyrano[3,2-c]pyridines, pyrazolo[4,3-c]pyridines, and pyrido[4,3-d]pyrimidines were synthesized and screened for their in vitro antioxidant activity. Compounds 13, 14, 15, 23, 29, 30, and 31 exhibited the most active oxygen free-radical scavenger activity with percentage inhibitions of 99.4, 99.6, 99.8, 97.3, 99.0, 99.3, and 99.5%; respectively, which is comparable to the curcumin potency. Most of the tested compounds proved to be safe towards peripheral multinuclear neutrophils (PMNs). The detailed synthesis and antioxidant activity data are reported.

Synthesis and antitumor activity of some curcumin analogs.

In this study, four new curcurmin analogs (compounds 1, 2, 17 and 18) were synthesized. 17 [3,5-bis(4-hydroxy-3-methoxy-5-methylcinnamyl)N-methylpiperidone] showed high activity with GI50, TGI, and LC50 MG-MID values of 21.3, 70.7, and 97.7 microM, respectively. 18 [3,5-bis(4-hydroxy-3-methoxy-5-methylcinnamyl)-N-ethylpiperidone] showed the highest activity in this study with GI50, TGI, LC50 MG-MID values of 4.4, 33.8, 89.1 microM, respectively. 18 is even more active than curcumin with GI50, TGI, LC50 MG-MID values of 38.4, 35.6, 66.0 microM; respectively. 8 showed moderate selectivity towards Leukemia cell line-subpanel with a ratio of 5.6 (curcumin ratio: 1.2 for the same subpanel). The in vitro anti-tumor screening reveals that the results go hand in hand with the in vitro free radical scavenging effects. The antioxidant effect of these compounds depends mainly on the stabilization of the formed phenoxy free radical for which the p-hydroxy phenyl moiety is essential. o-substitution by electron-donating groups like the o-methoxy group (and to a even higher degree by the ethoxy group) increases the stability of phenoxy free radical, hence increasing both free scavenging and anti-tumor effects. Increasing the alkyl group chain on the N in the series of substituted N-alkyl piperidones as well as the extension of conjugation, increases the stabilization of phenoxy free radical and thereby the activity towards both free radical scavenging and anti-tumor effects. This may be attributed to an increased positive inductive effect and/or increased lipophilicity of the new compounds, a fact which is proven by the superior activities of compounds 17 and 18.

Synthesis of curcumin analogues as potential antioxidant, cancer chemopreventive agents.

New series of 3, 5-bis(substituted benzylidene)-4-piperidones, 2, 7-bis(substituted benzylidene)cycloheptanones, 1, 5-bis(substituted phenyl)-1, 4-pentadien-3-ones, 1, 7-bis(substituted phenyl)-1, 6-heptadien-3, 5-diones, 1, 1-bis(substituted cinnamoyl)-cyclopentanes, and 1, 1-bis(substituted cinnamoyl)cyclohexanes have been synthesized and tested for their antioxidant activity. Among the tested compounds, compounds II(4), II(9) II(10), II(11), V(1), and V(4) exhibited higher free radical scavenger activity with % inhibition values of 90.71, 91.24, 96.91, 94.26, 99.23, and 99.85%, respectively. Moreover, compound V(1) is the safest member toward peripheral multinuclear neutrophils (PMNs) with a % viability value of 91%. Detailed synthesis, spectroscopic, and biological data are reported.

Synthesis, in vitro and in vivo evaluation of a delivery system for targeting anticancer drugs to the brain.

A 1, 4-dihydropyridine <--> pyridinium salt type redox system is described as a general and flexible method for site-specific and sustained delivery of drugs to the brain. This concept was used in the present investigation as a model to deliver an alkylating antitumor agent into the brain. A bis-(chloroethyl)amine drug was hooked to 1, 4-dihydropyridine chemical delivery system (CDS) through an amide linkage. Five new-target compounds (23-27) of the 1, 4-dihydropyridine CDS type were synthesized through the reduction of five new pyridinium quaternary intermediates (18-22). The synthesized 1, 4-dihydropyridines were subjected to various chemical and biological investigations to evaluate their ability to cross the blood-brain barrier (BBB), and to be oxidized biologically into their corresponding quaternary compounds. The in vitro oxidation studies showed that 1-benzyl-3-[N-[2-bis(2-chloroethyl)aminoethyl]-carbamoyl]-1, 4-dihydropyridine (23) and 1-(4-nitrobenzyl)-3-[N-[2-bis(2-chloroethyl)aminoethyl ]carbamoyl]-1, 4-dihydropyridine (27) could be oxidized into their corresponding quaternary compounds 18 and 22 respectively, at an adequate rate, which ensure the release of the carried anticancer drug. The in vivo studies showed that compound 23 was able to cross the BBB at detectable concentrations. On the other hand, the in vitro alkylation activity studies revealed that 1-(4-nitrobenzyl)-3-[N-[2-bis(2-chloroethyl)aminoethyl]carbamoyl]pyridinium bromide (22) is an alkylating agent with activity comparable to the known drug chlorambucil.

Synthesis and biological evaluation of some quinazoline derivatives as antitumor and antiviral agents.

A new series of 4-(4-aryl-1-piperazinyl)quinazolines 4a-f, 4-(3-substituted phenylamino)quinazoline derivatives 5a-h, 2-methoxycarbonylphenylaminoquinazoline derivatives 6a, b, 2-hydrazinocarbonylphenylaminoquinazolines 7a, b and 2-aryl-1-(substituted 4-quinazolinyl)-1,4-dihydro-5-oxo-5H-1,3,4-benzotriazepines 8a-j have been synthesized and tested for their antitumor and antiviral activities. Among them, compounds 5a-d exhibited broad spectrum antitumor activity with full panel median growth inhibition (GI50) at concentrations of 3.2, 2.0, 4.8, 4.0 mumol/l and total growth inhibition at concentrations of 56.5, 51.0, 63.0 and 73.0 mumol/l, respectively. Compounds 7a and 7b showed moderate selectivity toward leukemia cell line. On the other hand, compounds 8a and 8b showed moderate anti HIV-1 potency with EC50 values of 40.5 and 52.8 mumol/l, respectively. The detailed synthesis, spectroscopic and biological data are reported.

Synthesis and antiinflammatory screening of some quinazoline and quinazolyl-4-oxoquinazoline derivatives.

Synthesis of some new derivatives of 2-aryl-4-oxo-1-(4-quinazolyl)quinazolines is described. Methyl N-(4-quinazolyl)anthranilate was allowed to react with phenyl iso(thio)cyanate to give 3-phenyl-1-(4-quinazolyl)-1, 2, 3, 4-tetrahydro-2, 4-dioxo- and 4-oxo-2-thioxoquinazolines (3a and 3b respectively) Alternatively, anthranilic acid amide derivatives were subjected to cyclization with aromatic aldehydes to give 2-aryl-4-oxo-1-(4-quinazolyl)-1, 2, 3, 4-tetrahydroquinazolines 5. On the other hand, 2-chloro-4-(4-substituted 1-piperazinyl)quinazoline derivatives were subjected to the same type of reactions at the 2-position to afford the corresponding quinazoline derivatives 8 and 10 respectively. Furthermore, the acid amide 4b cyclized with acid chlorides to give the corresponding 2-aryl-1-(2-chloro-4-quinazolyl)-4-oxo-1, 4-dihydroquinazolines 11 from which the triazoloquinazoline derivatives 13 and 15 were synthesized through the intermediate hydrazine derivatives 12. Most of the newly synthesized compounds were tested for their antiinflammatory activities. However, some of the novel compounds were found to exhibit good antiinflammatory potencies.