Design and Synthesis of 2‐Phenoxynicotinic Acid Hydrazides as Anti‐inflammatory and Analgesic Agents

A series of 2‐phenoxynicotinic acid hydrazides were synthesized and evaluated for their analgesic and anti‐inflammatory activities. Several compounds having an unsubstituted phenyl/4‐pyridyl or C‐4 methoxy substituent on the terminal phenyl ring showed moderate to high analgesic or anti‐inflammatory activity in comparison to mefenamic acid as the reference drug. The compounds with highest anti‐inflammatory activity were subjected to in vitro COX‐1/COX‐2 inhibition assays and showed moderate to good COX‐1 and weak COX‐2 inhibition activities.     

Dependency of Gastrointestinal Toxicity on Release Rate of Tiaprofenic Acid: A Novel Pharmacokinetic-Pharmacodynamic Model

Purpose. To test the hypothesis that modification of release pattern of nonsteroidal anti-inflammatory drugs (NSAIDs) formulations shifts gastrointestinal (GI) toxicity of the drugs from the upper GI region to the distal intestine. Methods. We assessed tiaprofenic acid (TA)-induced upper and lower increased GI permeability (a surrogate marker of toxicity) after administration of 20 mg and 40 mg/kg regular release (powder) and modified release formulations [sustained release (SR) beads and diethyl--cyclo-dextrin (DCD):TA inclusion complex (INC)]. Urinary excretion of oral doses of GI permeability probes sucrose and ⁵¹Cr-EDTA was determined as measures of gastroduodenal and distal intestine, respectively. Pharmacokinetics of TA enantiomers were also studied following administration of a single 20 mg/kg dose of racemic TA as oral SR beads and iv solution. For powder and INC, previously reported pharmacokinetic data were used. Results. Regular powder significantly increased the permeability at the gastroduodenal level. Modified-release formulations, on the other hand, did not cause damage in the gastroduodenum but produced significant increase in the permeability of the lower intestine. Consequently, to assess the pharmacokinetic-pharmacodynamic relationship, a new model was developed in which contribution of toxicity resulted from direct exposure to the drug was considered. Conclusions. Since the observed site of GI damage corresponds to the site of release and absorption of NSAID from the formulation, the possibility of a shift in the site of damage must be considered for the modified release formulations. A parallel evaluation of upper and lower GI toxicity is essential for a complete assessment of NSAID-induced GI damage.     

Synthesis,Molecular Docking,and Biological Evaluation of Some Novel Hydrazones and Pyrazole Derivatives as Anti‐inflammatory Agents

2‐Hydrazinyl‐N‐(4‐sulfamoylphenyl)acetamide 3 was the key intermediate for the synthesis of novel hydrazones 4–10 and pyrazole derivatives 11–17 . All compounds were tested for their in vivo anti‐inflammatory activity and their ability to inhibit the production of PGE₂ in serum samples of rats. IC₅₀ values for the most active compounds for inhibition of COX‐1 and COX‐2 enzymes were determined in vitro, and they were also tested for their ulcerogenic effect. Molecular docking was performed on the active site of COX‐2 to predict their mode of binding to the amino acids. Most of the synthesized compounds showed good anti‐inflammatory activity especially compounds 3, 4, 8, 9, 15, and 17 which showed better activity than diclofenac as the reference drug. Compounds 3, 8, 9, 13, and 15–17 were less ulcerogenic than indomethacine as the reference drug. Most of the synthesized compounds interacted with Tyr 385 and Ser 530 in molecular docking study with additional hydrogen bond for compound 17 . Compound 17 showed good selectivity index value of 11.1 for COX‐1/COX‐2 inhibition in vitro.     

Synthesis and Evaluation of Novel 2‐Substituted‐quinazolin‐4(3H)‐ones as Potent Analgesic and Anti‐inflammatory Agents

A novel series of 2‐substituted‐quinazolin‐4(3H)‐ones were synthesized by reacting 3,5‐disubstituted‐anthranilic acid with acetic anhydride/benzoyl chloride, which were further reacted with different primary amines to obtain 2,6,8‐substituted‐quinazolin‐4(3H)‐ones 6a–f , 7 , 8 . All the synthesized compounds were characterized and screened for analgesic and anti‐inflammatory activities. Compounds 6,8‐dibromo‐2‐phenyl‐3‐(4′‐carboxyl phenyl)quinazolin‐4(3H)‐one 7 and 6,8‐dibromo‐2‐phenyl‐3‐(2′‐phenylethanoic acid)quinazolin‐4(3H)‐one 8 displayed good analgesic and anti‐inflammatory activity in comparison to the reference standards acetyl salicylic acid and indomethacin, respectively.     

Design,Synthesis, and Biological Evaluation of Novel Quinazoline Derivatives as Anti‐inflammatory Agents against Lipopolysaccharide‐induced Acute Lung Injury in Rats

Quinazoline has been reported to exhibit multiple bioactivities. The aim of this study was to discover new quinazoline derivatives with preventive effect on lipopolysaccharide‐induced acute lung injury via anti‐inflammatory actions. Thirty‐three 4‐amino quinazolin derivatives were synthesized and screened for anti‐inflammatory activities in lipopolysaccharide‐induced macrophages. The most potent four compounds, 6h, 6m, 6p , and 6q , were shown dose‐dependent inhibition against lipopolysaccharide‐induced TNF‐α and IL‐6 release. Then, the preliminary structure–activity relationship and quantitative structure–activity relationship analyses were conducted. To further determine the effects of quinazolines on acute lung injury treatment, lipopolysaccharide‐induced acute lung injury model was employed. Male Sprague Dawley rats were pretreated with 6m or 6q before instillation of lipopolysaccharide. The results showed that 6m and 6q, especially 6q , obviously alleviated lung histopathological changes, inflammatory cells infiltration, and cytokines mRNA expression initiated by lipopolysaccharide. Taken together, this work suggests that 6m and 6q suppressed the lipopolysaccharide‐induced acute lung injury through inhibition of the inflammatory response in vivo and in vitro, indicating that quinazolines might serve as potential agents for the treatment of acute lung injury and deserve the continuing drug development and research.     

Synthesis of Novel Substituted Thiourea and Benzimidazole Derivatives Containing a Pyrazolone Ring as Anti‐Inflammatory Agents

Two series of new 1‐(alkyl/aryl)‐3‐{2‐[(5‐oxo‐4,5‐dihydro‐1H‐pyrazol‐3‐yl)amino]phenyl}thioureas 2a – h and 5‐[2‐(substituted amino)‐1H‐benzimidazol‐1‐yl]‐4H‐pyrazol‐3‐ols 3a – i were designed and synthesized as anti‐inflammatory agents. The cyclooxygenase inhibitory activity of the newly synthesized compounds was investigated. All the compounds showed non‐selective inhibition of COX‐1 and COX‐2 enzymes which was consistent with their docking results. Compounds 2c , 2f , 2g , 3b , and 3g that showed the highest COX‐2 inhibitory activity were selected for further in vivo testing as anti‐inflammatory agents using diclofenac as a reference drug. Two of the test compounds ( 2c and 3b ) showed potent anti‐inflammatory activity comparable to that of diclofenac with lower ulcerogenic effect relative to indomethacin. SAR study of the two series as cyclooxygenase inhibitors and anti‐inflammatory agents was also provided.     

Synthesis and Biological Evaluation of 4‐Arylphthalazones Bearing Benzenesulfonamide as Anti‐Inflammatory and Anti‐Cancer Agents

Nine 4‐arylphthalazones bearing benzenesulfonamide (2a – i ) were synthesized by the condensation of the appropriate 2‐aroylbenzoic acid ( 1a – i ) and 4‐hydrazinobenzenesulfonamide in ethanol. The structures of these compounds were elucidated by elemental analysis, IR, ¹H NMR, ¹³C NMR, and MS spectroscopy. Two compounds, 2b and 2i , showed significant anti‐inflammatory activity comparable to that of the standard drug celecoxib in the carrageenan‐induced rat paw edema model. These compounds ( 2b and 2i ) had selective inhibitory activity towards the COX‐2 enzyme. Compound 2b had a better selectivity ratio (COX‐1/COX‐2) compared to that of celecoxib and can be used as a novel template for the design of selective COX‐2 inhibitors. Compounds 2d and 2i were screened for their antiproliferative activity toward 60 human cancer cell lines by the National Cancer Institute (USA). The compounds 2d and 2i displayed mild activity toward the renal cancer cell line UO‐31.     

Synthesis,Molecular Modeling,and Biological Evaluation of Novel 1, 3‐Diphenyl‐2‐propen‐1‐one Based Pyrazolines as Anti‐inflammatory Agents

A novel series of 1,3‐diphenyl‐2‐propen‐1‐one (chalcone) derivatives was synthesized by a simple, eco‐friendly, and efficient Claisen–Schmidt condensation reaction and used as precursors for the synthesis of new pyrazoline derivatives. All the synthesized compounds were screened for anti‐inflammatory related activities such as inhibition of phospholipase A₂ (PLA₂), cyclooxygenases (COX‐1 and COX‐2), IL‐6, and TNF‐α. The results of the above studies show that the compounds synthesized are effective inhibitors of above pro‐inflammatory enzymes and cytokines. Overall, the results of the studies reveal that the pyrazolines with chlorophenyl substitution ( 1b – 6b ) seem to be important for inhibition of enzymes and cytokines. Molecular docking experiments were performed to clarify the molecular aspects of the observed COX‐inhibitory activities of the investigated compounds.     

Synthesis,Anti‐MRSA,and Anti‐VRE Activity of Hemin Conjugates with Amino Acids and Branched Peptides

The increasing prevalence of antibiotic‐resistant bacterial strains has necessitated the synthesis of novel antibacterial agents. It was previously shown that naturally occurring metalloporphyrin hemin possesses dark antibacterial activity against Gram‐positive bacteria. To improve hemin antibacterial activity, we synthesized a number of hemin conjugates with amino acids and branched peptides. Arginine‐containing hemin conjugates demonstrated high antibacterial activity against Gram‐positive bacteria including methicillin‐ and vancomycin‐resistant strains in vitro. Most of the synthesized conjugates showed low toxicity against human erythrocytes and leukocytes.     

Aryl‐Heteroaryl Derivatives as Novel Wake‐Promoting Agents

In search of a next generation molecule to the novel wake‐promoting agent modafinil, a series of aryl‐heteroayl‐derived wakefulness enhancing agents (in rats) was developed. From this work, compound 16 was separated into its enantiomers to profile them individually.