A diazen-1-ium-1,2-diolated nitric oxide donor ester prodrug of 3-(4-hydroxymethylphenyl)-4-(4-methanesulfonylphenyl)-5 H -furan-2-one: Synthesis, biological evaluation and nitric oxide release studies

New indomethacin analogs as selective COX-2 inhibitors: Synthesis, COX-1/2 inhibitory activity, anti-inflammatory, ulcerogenicity, histopathological, and docking studies

New indomethacin analogs 4a-g, 5, 6, 8a, and 8b were synthesized to overcome the nonselectivity and ulcer liability of indomethacin. All newly synthesized compounds were more potent against cyclooxygenase 2 (COX-2; IC₅₀ value range: 0.09-0.4 μМ) as compared with celecoxib (IC₅₀  = 0.89 μМ). Compounds 4a, 4b, 4d, 5, and 6 showed the highest COX-2 selectivity index (SI range = 4.07-6.33) as compared with indomethacin (SI = 1.14) and celecoxib (SI = 3.52). Additionally, 4a, 4b, 4d, 5, and 7 showed good anti-inflammatory activity with edema inhibition (79.36-88.8%), relative to celecoxib (78.96%) and indomethacin (90.43%), after 5 h. Also, ulcerogenic effects and histopathological examination were assessed for the most potent analogs, 4b, 4d, 5, and 6, to determine their safety. The results can shed light on indomethacin analog 5 as a remarkable anti-inflammatory lead compound with a good safety profile (ulcer index = 10.62) close to the nonulcerogenic drug celecoxib (ulcer index = 10.53) and better than indomethacin (ulcer index = 18.50). Docking studies were performed in the COX-2 active site for the most active compounds, to test their selectivity and to confirm their mechanism of action.

Design, Synthesis and Evaluation of Novel Phthalimide Derivatives as in Vitro Anti-Microbial, Anti-Oxidant and Anti-Inflammatory Agents

Sixteen new phthalimide derivatives were synthesized and evaluated for their in vitro anti-microbial, anti-oxidant and anti-inflammatory activities. The cytotoxicity for all synthesized compounds was also determined in cancer cell lines and in normal human cells. None of the target derivatives had any cytotoxic activity. (ZE)-2-[4-(1-Hydrazono-ethyl) phenyl]isoindoline-1,3-dione (12) showed remarkable anti-microbial activity. Its activity against Bacillus subtilis was 133%, 106% and 88.8% when compared with the standard antibiotics ampicillin, cefotaxime and gentamicin, respectively. Compound 12 also showed its highest activities in Gram negative bacteria against Pseudomonas aeruginosa where the percentage activities were 75% and 57.6% when compared sequentially with the standard antibiotics cefotaxime and gentamicin. It was also found that the compounds 2-[4-(4-ethyl-3-methyl-5-thioxo-1,2,4-triazolidin-3-yl)phenyl]isoindoline-1,3-dione (13b) and 2-[4-(3-methyl-5-thioxo-4-phenyl-1,2,4-triazolidin-3-yl)phenyl]isoindoline-1,3-dione (13c) had anti-oxidant activity. 4-(N'-{1-[4-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-phenyl]-ethylidene}-hydrazino)-benzenesulfonamide (17c) showed the highest in vitro anti-inflammatory activity of the tested compounds (a decrease of 32%). To determine the mechanism of the anti-inflammatory activity of 17c, a docking study was carried out on the COX-2 enzyme. The results confirmed that 17c had a higher binding energy score (-17.89 kcal/mol) than that of the ligand celecoxib (-17.27 kcal/mol).

Synthesis, characterization and biological evaluation of novel 4'-fluoro-2'-hydroxy-chalcone derivatives as antioxidant, anti-inflammatory and analgesic agents

In an effort to develop safe and potent anti-inflammatory agents, a series of novel 4'-fluoro-2'-hydroxychalcones 5a-d and their dihydropyrazole derivatives 6a-d was prepared. It was synthesized via aldol condensation of 4'-fluoro-2'-hydroxyacetophenone with appropriately substituted aldehydes followed by cyclization with hydrazine hydrate. All the synthesized compounds were evaluated for their antioxidant, anti-inflammatory, cyclooxygenase inhibition selectivity and analgesic activities. The dimethoxychalcone 5a and its dihydropyrazole derivative 6a showed the highest antioxidant activity, while the monomethoxychalcone 5d and its dihydropyrazole derivative 6d showed the highest analgesic and anti-inflammatory activities. It was also found that there is a close correlation between 4'-fluoro-2'-hydroxychalcones 5a-d and their dihydropyrazole derivatives 6a-d in the screened biological activities. To explain the correlation between the synthesized chalcones and their dihydropyrazole derivatives, especially for the anti-inflammatory activity, docking studies were performed.

Structure-activity relationship of celecoxib and rofecoxib for the membrane permeabilizing activity

Non-steroidal anti-inflammatory drugs (NSAIDs) achieve their anti-inflammatory effect by inhibiting cyclooxygenase activity. We previously suggested that in addition to cyclooxygenase-inhibition at the gastric mucosa, NSAID-induced gastric mucosal cell death is required for the formation of NSAID-induced gastric lesions in vivo. We showed that celecoxib exhibited the most potent membrane permeabilizing activity among the NSAIDs tested. In contrast, we have found that the NSAID rofecoxib has very weak membrane permeabilizing activity. To understand the membrane permeabilizing activity of coxibs in terms of their structure-activity relationship, we separated the structures of celecoxib and rofecoxib into three parts, synthesized hybrid compounds by substitution of each of the parts, and examined the membrane permeabilizing activities of these hybrids. The results suggest that the sulfonamidophenyl subgroup of celecoxib or the methanesulfonylphenyl subgroup of rofecoxib is important for their potent or weak membrane permeabilizing activity, respectively. These findings provide important information for design and synthesis of new coxibs with lower membrane permeabilizing activity.