Design, synthesis and anti-inflammatory assessment of certain substituted 1,2,4-triazoles bearing tetrahydroisoquinoline scaffold as COX 1/2-inhibitors.

Aiming to discover effective and safe non-steroidal anti-inflammatory agents, a new set of 1,2,4-triazole tetrahydroisoquinoline hybrids 9a-g, 11a-g and 12a-g was synthesized and evaluated as inhibitors of COX-1 and COX-2. In order to overcome the adverse effects of highly selective COX-2 and non-selective COX-2 inhibitors, the compounds of this study were designed with the goal of obtaining moderately selective COX-2 inhibitors. In this study compounds 9e, 9g and 11f are the most effective derivatives against COX-2 with IC50 values 0.87, 1.27 and 0.58 µM, respectively which are better than or comparable to the standard drug celecoxib (IC50 = 0.82 µM) but with lower selectivity indices as required by our goal design. The results of the in vivo anti-inflammatory inhibition test revealed that compounds 9e, 9g and 11f displayed a higher significant anti-inflammatory activity than celecoxib at all-time intervals. In addition, these compounds significantly decreased the production of inflammatory mediators PGE-2, TNF-ɑ and IL-6. Compounds 9e, 9g and 11f had a safe gastric profile compared to indomethacin, also compound 11f (ulcerogenic index = 1.33) was less ulcerous than the safe celecoxib (ulcerogenic index = 3). Moreover, histopathological investigations revealed a normal architecture of both paw skin and gastric mucosa after oral treatment of rats with compound 11f. Furthermore, molecular docking studies were performed on COX-1 and COX-2 to study the binding pattern of compounds 9e, 9g and 11f on both isoenzymes.

Design and synthesis of new quinazolinone derivatives: investigation of antimicrobial and biofilm inhibition effects.

New quinazolin-4-ones 9-32 were synthesized in an attempt to overcome the life-threatening antibiotic resistance phenomenon. The antimicrobial screening revealed that compounds 9, 15, 16, 18, 19, 20 and 29 are the most broad spectrum antimicrobial agents in this study with safe profile on human cell lines. Additionally, compounds 19 and 20 inhibited biofilm formation in Pseudomonas aeruginosa, which is regulated by quorum sensing system, at sub-minimum inhibitory concentrations (sub-MICs) with IC50 values 3.55 and 6.86 µM, respectively. By assessing other pseudomonal virulence factors suppression, it was found that compound 20 decreased cell surface hydrophobicity compromising bacterial cells adhesion, while both compounds 19 and 20 curtailed the exopolysaccharide production which constitutes the major component of the matrix binding biofilm components together. Also, at sub-MICs Pseudomonas cells twitching motility was impeded by compounds 19 and 20, a trait which augments the cells pathogenicity and invasion potential. Molecular docking study was performed to further evaluate the binding mode of candidates 19 and 20 as inhibitors of P. aeruginosa quorum sensing transcriptional regulator PqsR. The achieved results demonstrate that both compounds bear promising potential for discovering new anti-biofilm and quorum quenching agents against Pseudomonas aeruginosa without triggering resistance mechanisms as the normal bacterial life cycle is not disturbed.

Anticancer profile and anti-inflammatory effect of new N-(2-((4-(1,3-diphenyl-1H-pyrazol-4-yl)pyridine sulfonamide derivatives.

A new series of N-(2-((4-(1,3-diphenyl-1H-pyrazol-4-yl)pyridine sulfonamide derivatives 11a-o were designed and synthesized based on our previous works. The new series was tested for its anticancer and anti-inflammatory effects. The anticancer profile of final target compounds was obtained by testing them over 60 cell lines belong to nine types of cancers. Compound 11c showed the highest percent inhibition, so its potency was measured over the most sensitive cell line to determine its IC50 over each cell. In addition, compound 11c was tested over kinase panel to get its biological target(s). Compound 11c had strong activity over JNK1, JNK2, p38a and V600EBRAF. All final target compounds were tested against the four kinases to build a structure activity relationship. Compound 11c was subjected to cell cycle analysis to check at which phase is affected by 11c. The anti-inflammatory effect of final target compounds was screened by testing their ability to inhibit both nitric oxide release and prostaglandin E2 production on raw 264.7 macrophages in addition to test their cytotoxic effect on the same cells. Compound 11n showed the highest ability to inhibit prostaglandin E2 and all compound showed moderate to low activity regarding inhibition of nitric oxide release. Compound 11n was investigated for its ability to reduce Interleukin 6 and TNF-alpha. In addition, compound 11n was tested for its effect on induced Nitric oxide synthase (iNOS), and COX-2 mRNA expression level and its effect on nitric oxide synthase (iNOS), COX-1 and COX-2 protein levels where it showed selectivity for COX-2 compared to COX-1 and iNOS.

Experimental design optimization of simultaneous enantiomeric separation of atenolol and chlorthalidone binary mixture by high-performance liquid chromatography using polysaccharide-based stationary phases.

In this work, enantiomeric separation of a drug combination of two chiral drugs, namely, atenolol and chlorthalidone, is described. Prior investigation of the effect of different variables on the resolution of the enantiomers' peaks and the total run time represented by the retention time of the last eluted peak was conducted using face-centered composite design. Twenty-two experiments were carried out by varying the chiral stationary phase type as a categorical factor and mobile phase composition including the percentage of ethanol and percentage of diethylamine as continuous factors. According to the optimization process, a mobile phase consisting of hexane:ethanol:DEA:TFA (60:40:0.2:0.1%, v/v/v/v) pumped at flow rate 1 ml min-1 onto Lux-Cellulose 2 stationary phase was applied for the chiral separation and quantification of the drug combination at 230 nm. Application of the developed method to the pharmaceutical formulation of this combination was successfully performed, and satisfactory percentage of recoveries was obtained. The method was also fully validated following International Conference on Harmonization (ICH) guidelines. This method could be of high value and relevance for application in quality control laboratories.

Design and synthesis of novel parabanic acid derivatives as anticonvulsants.

In this work a set of novel derivatives of parabanic acid 9a-d, 12a-d and 13a-d was synthesized and their anticonvulsant potential was evaluated. All the compounds under investigation exhibited anticonvulsant activity in both scPTZ and MES tests. In phase II anticonvulsant study, the trimethoxy phenyl derivative 9a evoked the highest potency among the tested compounds in scPTZ test. It displayed 1.72- and 17.05-folds activity more than the standard drugs phenobarbital and ethosuximide, respectively. In addition, the margin of safety for compound 9a is better than that of the reference antiepileptic drug ethosuximide. Also, compound 9a was devoid of hepatotoxicity indicated by measurements of serum level of ALT, AST, ALP, albumin and total protein. Furthermore, treatment with compound 9a significantly increased the GABA brain level by 2.56-folds compared to the control value. Additionally, molecular docking was performed on the active site of GABA-AT to clarify the interactions of the most potent compound 9a with the enzyme. In MES test, compound 12a exhibited the most potent activity against electric stimuli-induced seizures with the lowest ED50 = 13.7 mg/kg and protective index >36.5. Both candidates 9a and 12a could be a good starting point to develop new molecules as novel antiepileptic drugs.

Structural and biological survey of 7-chloro-4-(piperazin-1-yl)quinoline and its derivatives.

The 7-chloro-4-(piperazin-1-yl)quinoline structure is an important scaffold in medicinal chemistry. It exhibited either alone or as hybrid with other active pharmacophores diverse pharmacological profiles such as: antimalarial, antiparasitic, anti-HIV, antidiabetic, anticancer, sirtuin Inhibitors, dopamine-3 ligands, acetylcholinesterase inhibitors, and serotonin antagonists. In the presented review, a comprehensive discussion of compounds having this structural core is surveyed and illustrated.

Structure-retention relationship for enantioseparation of selected fluoroquinolones.

Fluoroquinolones are popular class of antibiotics with distinct chemical functionality. Most of them are ampholytes with one chiral center. Stereogeneic center is located either in the side ring of Gatifloxacin (GFLX) or in the quinolone core of Ofloxacin (OFLX). These two amphoteric fluoroquinolones have terminal amino groups in common. The unusual Nadifloxacin (NFLX) is an acidic fluoroquinolone with a core chiral center. Owing to chirality and functionality differences among GFLX, OFLX, and NFLX, we mapped these enantiomers onto structure-retention relationship. Amount of acetic acid modifier was studied in screened mobile phase and cellulose tris(3-chloro-4-methyl phenyl carbamate) (Lux cellulose-2) stationary phase. Experimental design of acetic acid% along with column temperature have been applied. Resolution and enantioselectivity have been related to structural features of the studied enantiomers. High amount of acid (0.4%) was optimum for the separation of either side chirality with a proximate amino group (GFLX) or core chirality without basic functionality (NFLX), while low amount (0.2%) is optimum for core chiral center with distal amino group (OFLX). Temperature has no significant effect on resolution and retention of enantiomers except for OFLX. Enantio-retention explains possible chiral selective and nonselective interactions. The proposed methods have been validated for pharmaceutical analyses.

Synthesis, molecular modeling studies, and anticonvulsant evaluation of novel 1-((2-hydroxyethyl)(aryl)amino)-N-substituted cycloalkanecarboxamides and their acetate esters.

A series of 1-((2-hydroxyethyl)(aryl)amino)-N-substituted cycloalkanecarboxamides IXa-l and their acetate esters Xa-l were designed and synthesized as new anticovulsant agents. The evaluation of the anticonvulsant effect was performed in vivo by subcutaneous pentylenetetrazole (scPTZ) and maximal electroshock (MES) tests in mice. Further, neurotoxicity, hepatotoxicity, and acute toxicity were determined. All the new candidates displayed 100% anticonvulsant activity in the scPTZ screen in the dose range of 0.0057-0.283 mmol/kg. The most potent compounds in the scPTZ screen were Xh (ED50 = 0.0012 mmol/kg), Xd (ED50 = 0.002 mmol/kg), Xf (ED50 = 0.004 mmol/kg), IXj (ED50 = 0.0047 mmol/kg), Xl (ED50 = 0.0076 mmol/kg), and Xi (ED50 = 0.008 mmol/kg). They exhibited higher fold activity in the anticonvulsant potential than the gold standards, phenobarbital and ethosuximide. Compound Xf was active in both scPTZ and MES screens. It showed ED50 of 0.016 mmol/kg in MES screen. In the neurotoxicity screens, none of the test compounds displayed any minimal motor impairment at the maximum administered dose. The 3D pharmacophore model using Biova 1 Discovery Studio 2016 programs exhibited high fit value. The anticonvulsant evaluation results were compatible with the molecular modeling study.

Synthesis, molecular modeling studies and anticonvulsant activity of certain (1-(benzyl (aryl) amino) cyclohexyl) methyl esters.

A series of (1-(benzyl (aryl) amino) cyclohexyl) methyl esters 7a-n were prepared and screened for their anticonvulsant profile. Screening of these esters 7a-n and their starting alcohols 6a and 6b revealed that compound 7k was the most potent one in the scPTZ screening test with an ED50 value of 0.0056mmol/kg being about 10- and 164-fold more potent than phenobarbital (ED50=0.056mmol/kg) and ethosuximide (ED50=0.92mmol/kg) as reference drugs, respectively. Meanwhile, in the MES test, compounds 7b and 7k at doses 0.0821mmol/kg and 0.0334mmol/kg, exerted 66% and 50% protection of the tested mice, respectively, compared with diphenylhydantoin, which exerted 100% protection at dose 0.16mmol/kg. In the neurotoxicity screen test, almost all esters 7a-n did not show any minimal motor impairment at the maximum administrated dose. The anticonvulsant effectiveness of esters 7a-n was higher than their corresponding alcohols 6a and 6b. Compounds 7b and 7k exhibited pronounced anticonvulsant activity devoid of neurotoxicity in minimal motor impairment test and hepatotoxicity in the serum enzyme activity assay. 3D pharmacophore model using Discovery Studio 2.5 programs showed high fit value. The obtained experimental results of sc-PTZ activity of compounds 7a-n was consistent with the molecular modeling study.

Design, Synthesis, and Cytotoxic Evaluation of Certain 7-Chloro-4-(piperazin-1-yl)quinoline Derivatives as VEGFR-II Inhibitors.

Signaling pathway inhibition of VEGFR-II is visualized as valuable tool in cancer management. In the current study, the synthesis of novel 1-4-(7-chloroquinolin-4-yl)piperazin-1-yl)-2-(N-substituted-amino)-ethanone derivatives (4a-t) was achieved through the amination of 2-chloro-1-(4-(7-chloroquinolin-4-yl)piperazin-1-yl)ethanone (3) with different secondary amines. The structures of the target compounds were confirmed by IR, 1 H-NMR, 13 C-NMR, HRMS, and microanalysis. Compounds 4a-t were subjected to in vitro anticancer screening against human breast cancer (MCF-7) and prostate cancer (PC3) cell lines. The highest cytotoxicty against both cell lines was displayed by 2-(4-(4-bromobenzyl)piperazin-1-yl)-1-(4-(7-chloroquinolin-4-yl)piperazin-1-yl)ethanone (4q), with IC50 values of 6.502 and 11.751 µM against MCF-7 and PC3 cells, respectively, compared with the standard drug doxorubicin (MCF-7: 6.774 µM, PC3: 7.7316 µM). Due to its notable activity toward MCF-7 cells, 4q was further evaluated as VEGFR-II inhibitor, showing an IC50 of 1.38 µM compared to sorafenib (0.33 µM). The docking study proved that 4q has a binding mode akin to that of VEGFR-II inhibitors.

Synthesis and Anticonvulsant Activity of Substituted-1,3-diazaspiro[4.5]decan-4-ones.

A series of novel spiroimidazolidinone derivatives 6a-d and 8a-x were synthesized and biologically evaluated for their anticonvulsant activity in the maximal electroshock seizure (MES) assay and the subcutaneous pentylenetetrazole (scPTZ) screening test. Compound 8w was the most active derivative in the scPTZ screening test with an ED50 value by about 5- and 83.6-fold lower than those of phenobarbital and ethosuximide as reference drugs, respectively. Most of the tested compounds exhibited moderate to weak activity in the MES screen test, except for 8a which displayed 100% protection at 0.09 mmol/kg. Moreover, all the test compounds did not show any minimal motor impairment in the neurotoxicity test.

Design, synthesis and antibacterial potential of 5-(benzo[d][1,3]dioxol-5-yl)-3-tert-butyl-1-substituted-4,5-dihydropyrazoles.

A series of 5-(benzo[d][1,3]dioxol-5-yl)-3-tert-butyl-1-substituted-4,5-dihydropyrazole derivatives 4a-e and 6a-g have been synthesized and spectrally characterized. The antibacterial activity of the novel candidates has been screened using the agar diffusion test. These compounds were endowed with high antibacterial activity against different Gram +ve and Gram -ve bacteria when compared with standard antibacterial drugs. In the light of zone of inhibition and MIC results, Sarcina and Staphylococcus aureus are the most sensitive bacteria where pyrrolidinomethanone derivative 4e showed MICs at 80 and 110 nM, respectively. While hydroxypiperidinoethanone derivative 6c showed MIC at 90 nM for Sarcina.

Anticonvulsant potential of certain new (2E)-2-[1-Aryl-3-(1H-imidazol-1-yl)propylidene]-N-(aryl/H)hydrazinecarboxamides.

Anticonvulsant potential and neurotoxicity of certain new imidazole-containing arylsemicarbazones 6a-p are reported. The test compounds 6a-p exhibited anticonvulsant activity mainly in the scPTZ screen. Compound 6p emerged as the most active surrogate displaying 100% protection at a dose level of 636 µ mol/kg in the scPTZ screen without any neurotoxicity. The assigned (E)-configuration of the title compounds 6a-p was confirmed via single crystal X-ray structure of compound 6g.

Anticonvulsant profiles of certain new 6-aryl-9-substituted-6,9-diazaspiro-[4.5]decane-8,10-diones and 1-aryl-4-substituted-1,4-diazaspiro[5.5]undecane-3,5-diones.

Synthesis and anticonvulsant potential of certain new 6-aryl-9-substituted-6,9-diazaspiro[4.5]decane-8,10-diones (6a-l) and 1-aryl-4-substituted-1,4-diazaspiro[5.5] undecane-3,5-diones (6m-x) are reported. The intermediates 1-[(aryl)(cyanomethyl)amino] cycloalkanecarboxamides (3a-f) were prepared via adopting Strecker synthesis on the proper cycloalkanone followed by partial hydrolysis of the obtained nitrile functionality and subsequent N-cyanomethylation. Compounds 3a-f were subjected to complete nitrile hydrolysis to give the respective carboxylic acid derivatives 4a-f which were cyclized under mild conditions to give the spiro compounds 5a-f. Ultimately, compounds 5a-f were alkylated or aralkylated to give the target compounds 6a-i and 6m-u. On the other hand, compounds 6j-l and 6v-x were synthesized from the intermediates 5a-f through alkylation, dehydration and finally tetrazole ring formation. Anticonvulsant screening of the target compounds 6a-x revealed that compound 6g showed an ED50 of 0.0043 mmol/kg in the scPTZ screen, being about 14 and 214 fold more potent than the reference drugs, Phenobarbital (ED50 = 0.06 mmol/kg) and Ethosuximide (ED50 = 0.92 mmol/kg), respectively. Compound 6e exhibited an ED50 of 0.019 mmol/kg, being about 1.8 fold more potent than that of the reference drug, Diphenylhydantoin (ED50 = 0.034 mmol/kg) in the MES screen. Interestingly, all the test compounds 6a-x did not show any minimal motor impairment at the maximum administered dose in the neurotoxicity screen.

Synthetic non-toxic anti-biofilm agents as a strategy in combating bacterial resistance.

The tremendous increase in the bacterial resistance to the available antibiotics is a serious problem for the treatment of various infections. Biofilm formation in bacteria significantly contributes to the bacterial survival in host cells, and is considered as an crucial factor, responsible for bacterial resistance. The response of the bacterial cells in the biofilm to antibiotics is completely different from that of the free floating planktonic cells of the same strain. The anti-biofilm agents that could inhibit the biofilm production without affecting the bacterial growth, apply less selective pressure over the bacterial strains than the traditional antibiotics; thus the development of bacterial resistance would be of low incidence. Many attempts have been performed to discover novel agents capable of interfering with the bacterial biofilm life cycle, and several compounds have shown promising activities in suppressing the biofilm production or in dispersing mature existing biofilms. This review describes the different chemical classes that have anti-biofilm effects against different Gram-positive and Gram-negative bacteria without affecting the bacterial growth.

N-Phenyl-2-(propan-2-yl-idene)-hydrazine-carboxamide.

In the title compound, C(10)H(13)N(3)O, the hydrazinecarboxamide N-N-C(=O)-N unit is nearly planar [maximum deviation = 0.018 (2) Å] and is inclined at a dihedral angle of 8.45 (10)° with respect to the plane of the phenyl ring. The mol-ecular structure is stabilized by an intra-molecular C-H⋯O hydrogen bond which generates an S(6) ring motif. In the crystal, mol-ecules are linked into an inversion dimer by pairs of N-H⋯O and C-H⋯O hydrogen bonds.

Synthesis and anti-candida potential of certain novel 1-[(3-Substituted-3-phenyl)propyl]-1H-imidazoles.

The synthesis and anti-Candida activity of 1-[(3-aroyloxy-3-phenyl)propyl]-1H-imidazoles 5a-f and 1-[(3-alkyl/aralkyl/phenyl-3-phenyl)propan-3-ol]-1H-imidazoles 5g-j are reported. The influence of the ester formation and different substitutions on the anti-Candida activity of the alcohol 4 was investigated. Among the newly developed bioactive chemical entities, compounds 5b and 5c displayed minimum inhibitory concentrations (MICs) against Candida albicans and Candida pseudotropicales comparable to that of tioconazole and more potent than miconazole.

A validated HPLC method for separation and determination of promethazine enantiomers in pharmaceutical formulations.

A simple, rapid, and validated method for separation and determination of promethazine enantiomers was developed. Promethazine was separated and quantitated on a Vancomycin Chirobiotic V column (250 x 4.6 mm), using a mixture of methanol, acetic acid, and triethylamine (100:0.1:0.1%, by volume) as a mobile phase at 20 degrees C and at a flow rate of 1 mL/min. The UV-detector was set to 254 nm. Acetyl salicylic acid (Aspirin) was used as an internal standard. The applied HPLC method allowed separation and quantification of promethazine enantiomers with good linearity (r > .999) in the studied range. The relative standard deviations (RSD) were 0.29 and 0.36 for the promethazine enantiomers with accuracy of 100.06 and 100.08. The limit of detection and limit of quantification of promethazine enantiomers were found to be 0.04 and 0.07 microg/mL, respectively. The method was validated through the parameters of linearity, accuracy, precision, and robustness. The HPLC method was applied for the quantitative determination of promethazine in pharmaceutical formulations.

A cyclohexanecarboxamide derivative with inhibitory effects on Schistosoma mansoni cercarial serine protease and penetration of mice skin by the parasite.

A cyclohexanecarboxamide derivative, N-phenyl-N-[1-(piperidine-1-carbonyl)cyclohexyl] benzamide (MNRC-5), was evaluated for its inhibitory effects on Schistosoma mansoni cercarial serine protease activity and cercarial penetration. MNRC-5 exerted an inhibitory effect on S. mansoni cercarial serine protease at serial concentrations of the specific chromogenic substrate Boc-Val-Leu-Gly-Arg-PNA for such enzyme family and the inhibitory coefficient (Ki) value was deduced. Moreover, topical treatment of mice tails with the most potent inhibitory concentration of MNRC-5 formulated in jojoba oil successfully blocked cercarial penetration as demonstrated by a significant reduction (75%; p < 0.05) in the recovered S. mansoni worms from treated mice in comparison to control ones whose tails were painted with jojoba oil base containing no MNRC-5. In addition, the IgM and IgG reactivities to crude S. mansoni cercarial, worm and egg antigens were generally lower in sera from treated infected mice than untreated infected mice. In conclusion, we report on a new serine protease inhibitor capable for blocking penetration of host skin by S. mansoni cercariae as measured by lowering worm burden and decrease in the levels of both IgM and IgG towards different bilharzial antigens upon topical treatment.

Design, synthesis and anticancer evaluation of novel 1,3-benzodioxoles and 1,4-benzodioxines.

A new set of 1,3-benzodioxoles and 1,4-benzodioxines was designed and synthesized starting from gallic acid as anticancer agents. The antiproliferative effect of the target compounds was evaluated against a panel of cancer cell lines (HepG2, PC-3, MCF-7 and A549) using MTT assay. The 1,4-benzodioxine derivative 11a manifested broad spectrum effect towards the four tested cancer cell lines (IC50 < 10 µM) with lower toxic effect on normal human cell line BJ1. Cell cycle progression of MCF-7 after treatment with compound 11a was studied where it induced cells accumulation at G2/M phase as well as increasing in the percentage of cells at pre-G1. Compound 11a is found to be a tubulin polymerization inhibitor with IC50 = 6.37 µM. Also, flow cytometeric analysis revealed that compound 11a could induce both early and late stage apoptosis in MCF-7 cell line. Moreover, the ability of this compound to stimulate apoptosis in the latter cell line was further confirmed by: increment of Bax/Bcl-2 ratio, increase the expression of tumor suppressor gene p53, boosting the levels of initiator and executioner caspases as well as raise in the amount of cytochrome C. In addition molecular docking study was accomplished on the colchicine binding site of tubulin (pdb: 1SA0) to illustrate the interactions of the most potent compound 11a to the receptor.