Synthesis,characterization and pharmacological evaluation of pyrazolyl urea derivatives as potential anti-inflammatory agents

p38α mitogen activated protein kinase (MAPK) inhibitors provide a novel approach for the treatment of inflammatory disorders. A series of fifteen pyrazolyl urea derivatives (3ao) were synthesized and evaluated for their p38α MAPK inhibition and antioxidant potential. Compounds 3ae, 3g and 3h showed low micromolar range potency (IC₅₀ values ranging from 0.037 ± 1.56 to 0.069 ± 0.07 µmol/L) compared to the standard inhibitor SB 203580 (IC₅₀ = 0.043 ± 3.62 µmol/L) when evaluated for p38α MAPK inhibition by an immunosorbent-based assay. Antioxidant activity was measured by a 2,2′-diphenyl-1-picryl hydrazyl radical (DPPH) free radical scavenging method and one of the compounds, 3c, showed better percentage antioxidant activity (75.06%) compared to butylated hydroxy anisole (71.53%) at 1 mmol/L concentration. Compounds 3ae, 3g and 3h showed promising in vivo anti-inflammatory activity (ranging from 62.25% to 80.93%) in comparison to diclofenac sodium (81.62%). The ulcerogenic liability and lipid peroxidation activity of these compounds were observed to be less in comparison to diclofenac sodium. These compounds also potently inhibited the lipopolysaccharide (LPS)-induced TNF-α release in mice (ID₅₀ of 3ac = 19.98, 11.32 and 9.67 mg/kg, respectively). Among the screened compounds, derivative 3c was found to be the most potent and its binding mode within the p38α MAPK is also reported.     

Synthesis and pharmacological evaluation of amide derivatives of non-steroidal anti-inflammatory drugs

In an effort to produce antirheumatic drugs with an increased therapeutic index, we have explored whether pro-drugs could be targeted to releasable leucocyte amidase(s) that would selectively regenerate an active form of the drug upon hydrolysis in inflammatory exudates. Amides of the non-steroidal anti-inflammatory drugs (NSAIDs), indomethacin and diclofenac, were prepared by condensing methyl or ethyl esters of various amino acids with the drugs. During a 10 min reaction with peripheral blood leucocytes, blood plasma, or liver extracts, the parent drugs were not regenerated from the amide substrates at 10⁻⁴ M. However, the ester protection of some amino acids was hydrolysed efficiently by leucocyte or liver enzymes, indicating potentially exploitable esterase activities for future targeting studies. Condensation products of indomethacin or diclofenac with phenylalanine were less inhibiting than the parent drug on prostaglandin E₂ release from cultured fibroblasts. However, they were more potent than the corresponding NSAID in competing for formyl-Met-Leu-Phe receptor binding on human neutrophils. This study illustrates practical difficulties encountered while implementing a drug targeting strategy including the selection of a suitable and tissue-specific regenerating enzyme and the residual pharmacological activity of the pro-drug, either similar to or different from the parent drug.     

Synthesis and pharmacological evaluation of some 4-oxo-quinoline-2-carboxylic acid derivatives as anti-inflammatory and analgesic agents

The synthesis and the pharmacological activity of a series of 1-aroyl derivatives of kynurenic acid methyl ester (4-oxo-quinolin-2-carboxy methyl (KYNA) esters), structurally related to NSAID indomethacin are described. The derivatives were screened in vivo for anti-inflammatory and analgesic activities. Most of the compounds exhibited good anti-inflammatory and analgesic activities. An automatic docking of the synthesized compounds was performed using X-ray structures of COX-1 and COX-2. Docking results are in good accordance with the experimental biological data.     

Synthesis and pharmacological evaluation of 2-hydroxymethylbenzamides as anti-inflammatory and analgesic agents

The ring opening of some phthalimide derivatives with sodium borohydride in methanol/water (6:1) afforded the corresponding 2-hydroxymethylbenzamides irrespective of the substituents. The most active members of the series evaluated for anti-inflammatory and analgesic activities were 2-hydroxymethyl-N-[4-(2-methoxyphenyl)-piperazin-1-yl]-ethylbenzamide (3d) and 2-hydroxymethyl-N-[4-(2-methoxyphenyl)-piperazin-1-yl]-propylbenzamide (3e), respectively.     

Design,synthesis, physicochemical,and pharmacological evaluation of gallic acid esters as non-ulcerogenic and gastroprotective anti-inflammatory agents

In our effort to identify the effective gastric sparing and protective anti-inflammatory agents, a series of gallic acid esters were synthesized, characterized, and studied to assess their physicochemical properties. Subsequently, the esters were evaluated for their anti-inflammatory activity and effect on gastric mucosa by most active compounds. All the compounds exhibited promising anti-inflammatory activity in carrageenan-induced rat paw edema model. In particular, 7a, 7c, 7f, and 7h emerged as the most active compounds in the series. The findings of gastric ulcer and antioxidant studies suggested these compounds as non-ulcerogenic and gastroprotective. Further, the predicted ADME properties of all the tested compounds were found to be in the ranges as predicted by QikProp for 95 % of known oral drugs and also satisfy the Lipinski’s rule of five.     

Synthesis and pharmacological evaluation of imidazopyridinium derivatives as neuromuscular blocking agents

A series of new imidazo[1,2-a]pyridinium derivatives have been prepared and studied as neuromuscular blocking agents in rats. These new substances are structurally related to fazadinium whose heterocyclic moieties were retained. All the new synthetized compounds are endowed with competitive neuromuscular blocking activity both in vitro and in vivo. Some were found to be equieffective with fazadinium with similar cardiovascular effects while some others possess more favorable therapeutic indexes.     

Synthesis and pharmacological evaluation of novel quinoxalines as potential nonulcerogenic anti-inflammatory and analgesic agents

Some new substituted quinoxaline and furo[2,3-b]quinoxaline derivatives have been synthesized and tested for their anti-inflammatory and analgesic activities and for their ulcerogenic potential. The pharmacological evaluation of selected synthesized compounds revealed that 5a was equipotent and compounds 3, 4b, 4e and 5b possessed strong anti-inflammatory activity in chronic inflammatory models compared with indometacin (CAS 53-86-1) as reference drug. In addition, compound 4a was the safest one and the others showed little ulcerogenic activity. All the tested compounds showed moderate analgesic activity compared to the reference drug.     

Synthesis and biological evaluation of novel pyrazoline derivatives as anti-inflammatory and antioxidant agents

A series of novel 5-aryl-3-cyclopropyl-4,5-dihydropyrazole derivatives 2a-p were synthesized via cyclization of chalcones 1a-h with thiosemicarbazide or semicarbazide HCl and evaluated as anti-inflammatory/antioxidant agents. The structures were confirmed by elemental analyses and spectral data. The free radical scavenging activity toward superoxide was determined. Their effect on hepatocytes viability and nitric oxide (NO) production in LPS-stimulated macrophages was also determined. The results showed that compounds 2e and 2n demonstrated the highest free-radical scavenging and anti-inflammatory activities, thus can be useful in the prevention of oxidative stress and inflammation-related disorders.     

Synthesis and biological evaluation of new quinoxaline derivatives as antioxidant and anti-inflammatory agents

We report the synthesis, anti-inflammatory, and antioxidant activities of novel quinoxaline and quinoxaline 1,4-di-N-oxide derivatives. Microwave-assisted methods have been used to optimize reaction times and to improve yields. The tested compounds presented important scavenging activities and promising in vitro inhibition of soybean lipoxygenase (LOX). Two of the best LOX inhibitors (compounds 7b and 8f) were evaluated as in vivo anti-inflammatory agents using the carrageenin-induced edema model. One of them (compound 7b) showed important in vivo anti-inflammatory effect (41%) similar to that of indomethacin (47%) used as the reference drug.     

Synthesis and pharmacological evaluation of the novel pseudo-symmetrical tamoxifen derivatives as anti-tumor agents

Four pseudo-symmetrical tamoxifen derivatives, RID-B (13), RID-C (14), RID-D (15), and bis(dimethylaminophenetole) (16), were synthesized via the novel three-component coupling reaction, and the structure-activity relationships of these pseudo-symmetrical tamoxifen derivatives were examined. It was discovered that 13 and 16 strongly inhibit the viability of the HL-60 human acute promyelocytic leukemia cell line, whereas 14 possesses a medium activity against the same cell line and 15 has no effect on the cell viability. The global anti-tumor activity of 13-16 against a variety of human cancer cells was assessed using a panel of 39 human cancer cell lines (JFCR 39), and it was shown that RID-B (13) strongly inhibited the growth of several cancer cell lines at concentrations of less than 1 microM (at 0.38 microM for SF-539 [central nervous system], at 0.58 microM for HT-29 [colon], at 0.20 microM for DMS114 [lung], at 0.21 microM for LOX-IMVI [melanoma], and at 0.23 microM for MKN74 [stomach]).     

Synthesis and biological evaluation studies of novel quinazolinone derivatives as antibacterial and anti-inflammatory agents

Some novel 6,8-diiodo-2-methyl-3-substituted-quinazolin-4(3H)-ones bearing sulfonamide derivatives (4–11) were synthesized in good yields and evaluated for their possible antibacterial, anti-inflammatory activities and acute toxicity. The structures of the synthesized compounds were confirmed on the basis of their spectral data and elemental analysis. Their antibacterial activities were evaluated by the agar well diffusion method while their anti-inflammatory activities were evaluated by the carrageenan-induced hind paw edema test. All the tested compounds showed considerable antibacterial activities and high to moderate anti-inflammatory activities that last for 12 h compared to ibuprofen. All the tested compounds showed no toxic symptoms or mortality rates 24 h post-administration at tested anti-inflammatory doses. In addition, LD₅₀ for all tested compounds was higher than that for ibuprofen implying their good safety margin. The obtained results showed that the most active compounds could be useful as a template for future design, modification and investigation to produce more active analogs.     

Synthesis and evaluation of fused pyrimidine derivatives as anti-inflammatory, antiproliferative and antimicrobial agents

In this study, condensation of 2-amino-5-chlorobenzoic acid with benzoyl chloride afforded 2-benzamido-5-chloro benzoic acid which on cyclization with different primary amines yielded the corresponding 6-chloro-2-phenyl-3-substituted quinazolin-4(3H)-ones (V1–V8). The reaction was monitored by thin layer chromatographic analysis. The structure of the synthesized compounds was confirmed by spectral studies and elemental analysis. All these compounds were screened for their anti-inflammatory, antiproliferative and antimicrobial activities. Anti-inflammatory activity was done by rat paw oedema method. Compounds V6 and V5 showed a good percentage inhibition of inflammation at the 2nd and the 3rd?h, respectively. Antiproliferative activity was carried out by MTT assay against Chang liver, Hep2 and HeLa cell lines. Compounds V1, V5 and V8 showed antiproliferative activity at low concentrations. The minimum inhibitory concentrations (MIC) of the synthesized compounds against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus flavus was studied by microdilution assay. Compound V4 was found to be a potent antimicrobial agent against the organisms tested. Further, it was selected for time kill study. These data revealed that the compounds containing chloro- and/or fluoro-substituted phenyl ring or N,N-dimethyl ethyl substitutions in the quinazolin-4(3H)-ones led to increase of their biological activities.     

Synthesis, evaluation, and molecular docking studies of cycloalkyl/aryl-3,4,5-trimethylgallates as potent non-ulcerogenic and gastroprotective anti-inflammatory agents

In our effort to identify the effective gastric sparing and protective anti-inflammatory agents, a series of cycloalkyl/aryl-3,4,5-trimethylgallates were synthesized and characterized. The physicochemical properties were studied to assess the lipophilicity and chemical stability. Subsequently, the compounds were evaluated for their anti-inflammatory activity and effect on gastric mucosa by most active compounds. All the compounds exhibited promising anti-inflammatory activity. In particular, 4a, 4b, 4g, and 4h emerged as the most active compounds in the series. The results of gastric mucosal studies and biochemical estimations suggested that these compounds are non-ulcerogenic and gastroprotective. The molecular docking analysis was performed to understand the binding interactions of these compounds to cyclooxygenase isoenzyme (COX-1 and COX-2). The results from this investigation suggests cycloalkyl/aryl-3,4,5-trimethylgallates as potent safer gastrosparing and protective anti-inflammatory agents.     

Synthesis and pharmacological evaluation of new topical anti-inflammatory steroids.

The purpose of this research was to develop new topical steroid derivatives showing reduced systemic effects. Pregna-16 alpha,17-carboxycyclic acetal derivatives have been recently synthesized by reacting triamcinolone with methyl acetylalkanoate in the presence of a catalytic amount of perchloric acid. In testing for the anti-inflammatory activity of the compounds, rat cotton-pellet granuloma inhibition bioassay and mouse croton-oil-induced ear oedema inhibition bioassay were employed. One of the synthesized compounds, (22R)-9 alpha-fluoro-11 beta,21-dihydroxy-3,20-dioxo-16 alpha, 17-(methyl, methoxycarbonylmethyl)methylenedioxy-1,4-pregnadiene (I), showed more or less the same activity as shown by prednisolone in the granuloma inhibition test. However, compound I showed higher activity in the ear oedema inhibition test when applied topically (ID50 = 0.002 mg), as compared to prednisolone (ID50 = 0.006 mg) and triamcinolone (ID50 = 0.026 mg). When compound I was applied to mice, and thymus involution was measured for judging systemic effects, it was found that compound I did not show any significant thymus involution up to 0.1 mg/mouse (systemic administration) and 0.5 mg/mouse (topical administration). Because of its significantly reduced systemic effects, this compound is a promising topical anti-inflammatory steroid.     

Synthesis of baicalein derivatives as potential anti-aggregatory and anti-inflammatory agents

The direct acylation of trimethoxyphenol (1) with substituted cinnamoyl chlorides followed by Fries rearrangement and cyclization afforded a practical route for the synthesis of novel baicalein derivatives 4 functionalized on the B-ring in good overall yields. In the methylthiazoletetrazolium bromide (MTT) assay, none of the synthetic polyhydroxyflavonoids were cytotoxic at concentrations up to 200 microM on lipopolysaccharide (LPS)-activated murine RAW 264.7 macrophages over 24 h, while in the same cells they significantly inhibited NO production. Among the derivatives, 4d (IC50=46.1 +/- 0.3 microM) was found to exhibit the most potent activity compared with N-nitro-(L)-arginine methyl ester (L-NAME, IC50 >300 microM). Compounds 4b, 4e, 4f, 4h and 4i remarkably inhibited platelet aggregation induced by arachidonic acid and collagen in rabbit washed platelets compared with aspirin. Analysis of their structure-activity relationships indicated that, in the structural modification on the B-ring of baicalein (4a), introduction of appropriate electro-withdrawing substituents such as 2-Cl (4b), 4-Cl (4d), and 4-phenyl (4i) notably increased the potency on the inhibition of LPS-activated NO production and arachidonic acid- and collagen-induced aggregation. Baicalein itself was equally effective in the inhibition of LPS-activated NO production and collagen-induced aggregation but less active against arachidonic acid-induced aggregation. Our in-vitro results suggested that by appropriate structural modification of baicalein it may be possible to develop novel therapeutic agents against platelet-aggregation and inflammation.     

Synthesis and pharmacological evaluation of some novel 2-pyrazolines bearing benzenesulfonamide as anti-inflammatory and blood glucose lowering agents

A series of novel pyrazolines (2a–l) bearing benzenesulfonamide moiety were synthesized by condensing appropriate chalcone (1a–l) with 4-hydrazinobenzenesulfonamide hydrochloride. Structure of all novel synthesized compounds was characterized on basis of elemental analysis data and spectral data (IR, ¹HNMR, MS). Compounds (2a–l) were screened for in vivo anti-inflammatory action in carrageenan-induced rat paw edema model and blood glucose lowering action in glucose fed hyperglycemic normal rats. Compounds 2a, 2e, and 2l showed significant anti-inflammatory action (more than 75 %) at 5 h and also showed superior gastrointestinal safety profiles as compared to celecoxib. One compound (2i) was found to exhibit significant blood glucose lowering activity.     

Synthesis and pharmacological evaluation of the antifibrillatory effect of fluorinated derivatives of carazolol and celiprolol: Comparison with propranolol

• 1.1. The effects of carazolol, celiprolol and their respective fluorinated derivatives (FD) on electrical stimulation threshold (EST) and ventricular fibrillation threshold (VFT) were compared with those of propranolol and propranolol-FD in Langendorff-perfused rabbit hearts.
• 2.2. Carazolol, carazolol-FD, propranolol and propranolol-FD produced significant dose-dependent elevation of both EST and VFT at all tested concentration levels. In contrast, celiprolol and celiprolol-FD did not produce a significant change in either threshold.
• 3.3. On a dosage basis, the order of antifibrillatory potency of these compounds is: carazolol-FD > propranolol-FD > carazolol > propranolol > celiprolol-FD > celiprolol.
• 4.4. The results of this study seem to indicate the importance of membrane stabilizing effect for a potent antifibrillatory action of β-adrenoceptor blocking agents. Furthermore, fluorination is demonstrated to produce more potent antifibrillatory activity than that of the parent drugs.

     

Synthesis and pharmacological evaluation of some thiolupinine derivatives.

A small set of 9-(lupinylthio)xanthene, -thioxanthenes and alpha-(lupinylthio)diphenylmethanes was prepared and found to inhibit the angiotensin II-induced contractions of guinea pig ileum. Some of these compounds were also moderately active in vitro as tracheal relaxants and one compound was more active than aspirin against arachidonic acid-induced platelet aggregation.     

Synthesis, anti-inflammatory and analgesic evaluation of thioxoquinazolinone derivatives

A series of 3-substituted-2-thioxoquinazolin-4(3H)-one derivatives have been synthesized and their structures have been elucidated on the basis of IR, (1)H-NMR, elemental analysis and mass spectroscopic studies. Anti-inflammatory and analgesic activity of the synthesized compounds was evaluated by Carrageenan induced rat paw edema method and Eddy's hot plate method respectively. Among the synthesized compounds N-(4-hydroxyphenyl)-N-(4-oxo-3-phenyl-2-thioxo-3,4-dihydroquinazolin-1(2H)methyl)acetamide (PTQ01) showed excellent anti-inflammatory activity. N-(4-ethoxyphenyl)-N-(3-(naphthalen-2yl)-4-oxo-2-thioxo-3,4-dihydroquinazolin-1(2H)-yl)methyl)acetamide (NTQ02), N-(4-Hydroxyphenyl)-N-((3-naphthalen-2-yl)-4-oxo-2-thioxo-3,4-dihydorquinazolin-1(2H)-ylmethyl)acetamide (NTQ01), N-((3-(4-ethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydoquinazolin-1(2H)-yl)methyl)-N-(4-hydroxyphenyl)acetamide (ETQ01) N-(3-(4-ethoxyphenyl)-4-oxo-2thioxo-3,4-dihydroquinazolin-1(2H)-ylmethyl)-N-(4-hydroxyphenyl)acetamide (ETQ04), N-(4-ethoxyphenyl)-N-((4-oxo-3-phenyl-2-thioxo-3,4-dihydoquinazolin-1(2H)-yl)methyl)acetamide (PTQ02) and N-(4-ethoxyphenyl)-N-(3-(4-ethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydoquinazolin-1(2H)-yl)methyl)acetamide (ETQ02) at a dose of 20 mg/kg exhibited significant anti-inflammatory activity compared to that of standard drug diclofenac sodium. The compound 2-(2,3-dimethylphenyl)(3-(4-ethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydroquinazolin-1-2H)-1ylmethylamino)benzoic acid PTQ03 and sodium 2-(2-((2,6-dichlrophenyl)(3-(4-oxo-2-thioxo-3,4-dihydroquinazolin-1(2H)-yl)methyl)amino)phenylacetate (PTQ04) showed moderate anti-inflammatory activity. The compounds PTQ01, PTQ02, PTQ04, ETQ01 and ETQ02 showed significant analgesic activity compared with that of standard drug pentazocin.