Synthesis, analgesic and anti-inflammatory evaluation of some new 3H-quinazolin-4-one derivatives

In this study, we have synthesized a series of 3H-quinazolin-4-ones in order to obtain new compounds with potential analgesic and anti-inflammatory activity. The structures of the newly synthesized compounds were confirmed by means of infrared, nuclear magnetic resonance and mass spectroscopy. Some compounds were evaluated for their analgesic and anti-inflammatory activities by writhing and carrageenan-induced rat paw edema tests, respectively. In comparison to the standard drug indomethacine, compounds 4, 6c, 12-14, 16, 18, 19, and 22 induced significant reduction in the writhing response while compounds 6c, 12, 14, 16, 18, and 22 produced a good dose-dependent anti-inflammatory activity. The best dual analgesic / anti-inflammatory relative activity was observed with compounds 6c, 14, 16, 18, and 22.     

Synthesis and pharmacological evaluation of some 3-(4-methylphenyl)-2-substituted amino-3H-quinazolin-4-ones as analgesic and anti-inflammatory agents

A variety of 3-(4-methyl phenyl)-2-substituted amino-3H-quinazolin-4-ones were synthesized by reacting the amino group of 2-hydrazino-3-(4-methyl phenyl)-3H-quinazolin-4-one with a variety of aldehydes and ketones. The starting material 2-hydrazino-3-(4-methyl phenyl)-3H-quinazolin-4-one was synthesized from 4-methyl aniline. The title compounds were investigated for analgesic, anti-inflammatory, and ulcerogenic index activities. While the test compounds exhibited significant activity, compounds Al, A2, and A3 showed more potent analgesic activity and the compound A3 showed more potent anti-inflammatory activity when compared to the reference standard diclofenac sodium. Interestingly, the test compounds showed only mild ulcerogenic potential when compared to aspirin.     

Synthesis, anti-inflammatory and analgesic activity of some new 4(3H)-quinazolinone derivatives

4(3H)-quinazolinone and pyrazole derivatives have been shown to have analgesic and anti-inflammatory properties. In this study, 14 new 3-methyl-4(3H)quinazolinone derivatives bearing 2-[1'-phenyl-3'-(substituted-phenyl)-2'-propenylidene]hydrazino or 2[5'-(substituted phenyl)-3'-phenyl-2'-pyrazolin-1'-yl] groups have been synthesized with the aim of obtaining new analgesic and anti-inflammatory leads. The structures were elucidated by means of UV, IR, 1H-NMR, 13C-NMR, mass spectroscopy, and elemental analysis data. The anti-inflammatory activities of the synthesized compounds were determined by carrageenan-induced hind paw edema test in mice. All the compounds showed statistically significant effects. For analgesic activity assessment, p-benzoquinone-induced writhing test was applied in mice. The results obtained were in accordance with the anti-inflammatory activity tests.     

Synthesis, analgesic and anti-inflammatory activity of 4-(2-phenoxyphenyl)semicarbazones

A series of 4-(2-phenoxyphenyl)semicarbazones was synthesized and evaluated for their analgesic and anti-inflammatory activities. Several compounds (e. g. 10h, 10i, and 11i) were found to be more potent than the reference drug mefenamic acid in the formalin test. Based on the results of an anti-inflammatory study, 1-(1-(2,5-dimethoxyphenyl)ethylidene)-4-(2-phenoxyphenyl)semicarbazide 11i was the most active compound.     

Synthesis and pharmacological investigation of 3-subsituted-amino-2-methylsulfanyl-5,6,7,8-tetrahydro-3H-benzo[4,5]thieno[2,3-d]pyrimidin-4-ones as analgesic and anti-inflammatory agents

In the present work, design, synthesis, and pharmacological evaluation of the analgesic, anti-inflammatory, and ulcerogenic-index activities of new 3-subsituted-amino-2-methylsulfanyl-5,6,7,8-tetrahydro-3H-benzo[4,5]thieno[2,3-d]pyrimidin-4-ones, structurally planed by exploiting a clear concept of bio-isosterism, are reported. All compounds exhibited significant analgesic and anti-inflammatory activity. Compounds A1, A3 showed higher analgesic activity and more potent anti-inflammatory activity than that of the reference compound diclofenac sodium. Interestingly, the test compounds showed only mild ulcerogenic potential when compared to that of acetylsalicylic acid.     

Synthesis of some floctafenine derivatives of expected anti-inflammatory/analgesic activity

New derivatives related to floctafenine were synthesized and representative examples were screened for their anti-inflammatory and analgesic activities. All compounds tested were found to exhibit anti-inflammatory and analgesic activities and some were more potent than the references, floctafenine and indomethacin, in carragenan-induced rat's paw edema. None of the tested compounds showed an ulcerogenic effect on the p-benzoquinone-induced writhing test in mice.     

Synthesis of novel 1-pyrazolylpyridin-2-ones as potential anti-inflammatory and analgesic agents

A new series of 4-alkyl/aryl-2-oxo-1-pyrazolyl-1,2-dihydropyridine-3-carbonitriles, pyrazolo[3,4-b]pyridine-5-carbonitriles and pyrido[2,3-d]pyrimidine-6-carbonitriles have been synthesized and tested for their anti-inflammatory and analgesic activities. Among the tested compounds, 3e and 8b exhibited comparable anti-inflammatory activity to the standard (indomethacin). Compounds 5, 7a, and 8b displayed potent analgesic activity. Detailed syntheses, spectroscopic and biological data are reported.     

Synthesis and anti-inflammatory activity evaluation of novel 7-alkoxy-1-amino-4,5-dihydro[1,2,4]triazole[4,3-a]quinolines

In this study, a novel series of 7-alkoxy-1-amino-4,5-dihydro[1,2,4]triazole[4,3-a]quinolines were synthesized by using 6-hydroxy-3,4-dihydro-2(1H)-quinolone as the starting material. These compounds were evaluated for anti-inflammatory activity through monitoring their ability to inhibit xylene-induced ear edema in mice. Some of the tested compounds exhibited significant activity, and the compounds 5f (7-(benzyloxy)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinolin-1-amine) and 5i (7-(p-chlorobenzyloxy)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinolin-1-amine) showed the highest anti-inflammatory activity (52% and 58% inhibition, respectively, at 2 h pre-administration) which were comparable to or even slightly more potent than the reference drug ibuprofen (55%). Furthermore, the structure-activity relationship of these 1,2,4-triazole quinolines was demonstrated.     

Synthesis of some new 2-(6-methoxy-2-naphthyl)- 5-aryl-1,3,4-oxadiazoles as possible non-steroidal anti-inflammatory and analgesic agents

The synthesis of some new 2-(6-methoxy-2-naphthyl)-5-aryl-1,3,4-oxadiazoles (4a-k) has been described. Ethyl-6-methoxy-2-naphthoate (1) yielded on treatment with hydrazine hydrate to 6-methoxy-2-naphthoic acid hydrazide (2). Compound 2 reacted with substituted aromatic carboxylic acids (3a-k) in phosphorus oxychloride yielded 2-(6-methoxy-2-naphthyl)-5-aryl-1,3,4-oxadiazoles (4a-k). Newly synthesized compounds were characterized by IR, (1)H-NMR and mass spectral data. All the compounds were screened for their anti-inflammatory and analgesic activity. Compound 4j exhibited promising anti-inflammatory and analgesic activities.     

Investigations of new pyridazinone derivatives for the synthesis of potent analgesic and anti-inflammatory compounds with cyclooxygenase inhibitory activity

In this study we describe the synthesis of two novel 4-phenyl-and 4-(2-chlorophenyl)-6-(5-chloro-2-oxo-3H-benzoxazol-7-yl)-3(2H)-pyridazinone derivatives (compounds 8a and b) and their testing as inhibitors of cyclooxygenases (COX-1 and COX-2). Both compounds inhibited COX-1 (by 59 % and 61 % for compounds 8a and 8b respectively and COX-2 (by 37 % and 28 % for compounds 8a and 8b respectively) at a concentration of 10 microM. Furthermore, we tested the analgesic and anti-inflammatory activities of the synthesized compounds in vivo by using the p-benzoquinone-induced writhing test and the carrageenan-induced hind paw edema model, respectively. Compounds 8a and 8b showed potent analgesic and anti-inflammatory activities without causing gastric lesions in the tested animals.     

Amide derivatives of [6-(5-methyl-3-phenylpyrazole-1-yl)-3(2H)-pyridazinone-2-yl]acetic acids as potential analgesic and anti-inflammatory compounds

In this study, amide derivatives of [6-(5-methyl-3-phenyl-pyrazole-1-yl)-3(2H)-pyridazinone-2-yl]acetic acid were synthesized and tested for their in vivo analgesic and anti-inflammatory activity by using the p-benzoquinone-induced writhing test and carrageenan-induced hind paw edema model, respectively. The analgesic and anti-inflammatory activity of the compounds 6a, 6d, 6e, 6g, 6h and 6m were more potent than that of aspirin as an analgesic and indomethacin as an anti-inflammatory drug, respectively. The other derivatives generally resulted in comparable activity to reference compounds. Inhibitor activity of the active compounds on cyclooxygenase isoforms was also investigated by using in vitro human whole blood assay and found that these derivatives did not exert their analgesic and anti-inflammatory activities through COX inhibition and other mechanisms might be involved.     

Synthesis of new 2-[1(2H)-phthalazinon-2-yl]acetamide and 3-[1(2H)-phthalazinon-2-yl]propanamide derivatives as antinociceptive and anti-inflammatory agents

As a consequence of our ongoing studies on heterocyclic compounds for new antinociceptive and anti-inflammatory agents bearing lactam functional group, new 2-[1(2H)-phthalazinon-2-yl]acetamide and 3-[1(2H)-phthalazinon-2-yl]propanamide derivatives have been synthesized. Among the compounds synthesized, compound (4e) was found the most active derivative in terms of antinociceptive and anti-inflammatory activities, without gastric lesions and bleeding at the given dose.     

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 analgesic and antiinflammatory activity of methyl 6-substituted-3(2h)-pyridazinone-2-ylacetate derivatives

A series of methyl 6-substituted-3(2H)-pyridazinone-2-ylacetates 9 were synthesized and their analgesic and anti-inflammatory effects were evaluated in the phenylbenzoquinone-induced writhing test (PBQ test) and carrageenan-induced paw edema method, respectively. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with reference nonsteroidal anti-inflammatory drugs. Methyl 6-(4-(4-fluorophenyl)piperazine)-3(2H)-pyridazinone-2-ylacetate 9e was found to be more active than acetylsalicylic acid (ASA). Methyl 6-(4-(2-ethoxyphenyl)piperazine)-3(2H)-pyridazinone-2-ylacetate 9c has shown an anti-inflammatory activity as compared to the standard compound indometacin at the carrageenan-induced paw edema method.A significant dependence of the anti-inflammatory effect on the substituents has been observed. The pharmacological study of these compounds confirms that modification of the chemical group at the position 6 of the 3(2H)-pyridazinone system influences analgesic and anti-inflammatory activities. The structures of these new pyridazinone derivatives were confirmed by their IR and (1)H-NMR spectra and elemental analysis.     

Synthesis, anticonvulsant, and anti-inflammatory activities of some new benzofuran-based heterocycles

Treatment of 2-bromoacetylbenzofuran (2) with pyridine afforded its corresponding pyridinium bromide 3. The latter salt reacted with some activated alkenes and acetylenes to give the corresponding indolizine derivatives. Treatment of the salt 3 with benzylidenemalononitriles 9 afforded polysubstituted aniline derivatives, however with arylidenecyanothioacetamides 15 it gave the corresponding 4,5-dihydrothiophenes. Bromide 3 also coupled with p-chlorobenzenediazonium salt followed by ammonium acetate to give the corresponding 1,2,4,5-tetrazine derivative. The biological activity of the newly synthesized compounds was examined and some of them were found to possess anticonvulsant and anti-inflammatory activities.     

Synthesis and analgesic and anti-inflammatory activity of some new (6-acyl-2-benzoxazolinone and 6-acyl-2-benzothiazolinone derivatives with acetic acid and propanoic acid residues

In this study for developing potent analgesic and anti-inflammatory compounds, we synthesized 6-acyl-2-benzoxazolinone and 6-acyl-2-benzothiazolinone derivatives with acetic acid and propanoic acid side chain, and performed preliminary screening of their in vivo analgesic and anti-inflammatory activities at a single dose of 100 mg/kg inmice by a p-benzoquinone-induced writhing test and a Carrageenaninduced hind paw edema model, respectively. We also determined their gastric ulceration effects in the tested animals. Propanoic acid derivatives were generally found to have higher analgesic and anti-inflammatory activities, and among them, 3-(6-benzoyl-2-benzothiazolinon-3-yl)propanoic acid (Compound 4 a) exhibited the highest analgesic and anti-inflammatory activity. However, all compounds showed lower anti-inflammatory effects than we observed for indomethacin at 10 mg/kg dose. Consequently, 6-acyl-2-benzoxazolinone/2-benzothiazolinones having propanoic acid side chain might lead to further studies for developing better candidates with potent analgesic and anti-inflammatory effects while acetic acid derivatives do not exhibit comparable satisfactory features.     

Synthesis of beta-hydroxypropanoic acid derivatives as potential anti-inflammatory, analgesic and antimicrobial agents

A series of new 3-(substituted) 3-hydroxy-propanoic acid ethyl esters 1a-c, hydrazides 2a-c, thiosemicarbazides 3a-f, and semicarbazides 3g, 3h has been synthesized. Cyclization of compounds 3a-d in basic medium yielded 1,2,4-triazole-5-thiones 4a-d. On the other hand, reaction of hydrazides 2a-c with CS(2 )in basic medium afforded 1,3,4-oxadiazole-5-thiones 5a-c. All the synthesized compounds were characterized by their physical and spectral analyses data. The newly synthesized compounds were evaluated for their anti-inflammatory, analgesic, and antimicrobial activities. Compounds 1c, 3g, 4a, 4b, 4c, and 5c exhibited comparable anti-inflammatory activity to that of indomethacin and compounds 1c, 4c, and 5c were more analgesics than acetyl salicylic acid. Compounds 4b, 4c, and 5c showed superior GI safety profile (33.3%, 33.3% and 50.0% ulceration) than that of indomethacin (100% ulceration) at 100 mg/kg oral dose. Compounds 4b, 4c, and 5c were also non-toxic with a median lethal dose (LD(50)) up to 200 mg/kg. The antibacterial and antifungal screenings identified compounds 3c, 4b, 4d, 5a, and 5b as the most effective against a variety of tested microorganisms.     

Synthesis and anti-inflammatory activities of new cyanopyrane derivatives fused with steroidal nuclei

Thirteen new heterocyclic derivatives containing a cyanopyrane ring fused to a steroidal moiety were conveniently synthesized and screened for their anti-inflammatory potencies comparable to that of the glucocorticoid prednisolone. Four compounds 5a, 5b, 6b, and 8 exhibited superior anti-inflammatory indices (in rats, protection against carrageenan induced edema and inhibition of plasma PGE). All the candidates were less toxic than the reference drug concerning LD(50) values. Synthetic steroidal structures fused to a substituted cyanopyrane ring seem to be a promising approach in search for novel leads for potent anti-inflammatory agents.     

Synthesis of novel substituted 7-(benzylideneamino)-4-methyl-2H-chromen-2-one derivatives as anti-inflammatory and analgesic agents

A series of novel Schiff' base-containing a 7-amino-4-methylcoumarin moiety have been synthesized III a-l, characterized by spectroscopic data and studied for their anti-inflammatory and analgesic activity. The results of the anti-inflammatory and analgesic activity evaluation of 7-(substituted benzylideneamino)-4-methyl-2H-chromen-2-one derivatives III a-l proved to be comparable or more potent with respect to the reference drugs. In particular, compounds 7-(4-chlorobenzylideneamino)-4-methyl-2H-chromen-2-one III f, 7-(2,4-dichlorobenzylideneamino)-4-methyl-2H-chromen-2-one III g and 7-(4-bromobenzylideneamino)-4-methyl-2H-chromen-2-one III h exhibited potent anti-inflammatory and analgesic activity.     

Synthesis,biological evaluation of certain pyrazolo[3,4-d]pyrimidines as novel anti-inflammatory and analgesic agents

In the present study, a series of pyrazolo[3,4-d]pyrimidin-4(5H)-ones linked at 5-position to thiazoline or thiazolidinone ring systems through imino linkage (5–8) was designed and synthesized. The compounds were assessed for their anti-inflammatory activity and analgesic in vivo. Also, their ability to inhibit ovine COX-1/COX-2 isozymes was evaluated using in vitro cyclooxygenase (COX) inhibition assay. The newly synthesized compounds 7, 8d, and 8e showed potent anti-inflammatory and analgesic activity. Moreover, compound 7 displayed preferential COX-2 inhibitory potency (IC₅₀ = 0.53 µM and COX-2 selectivity index = 10.07) which is more potent than the standard drug meloxicam. Interestingly, the tested compounds showed excellent gastrointestinal safety profile and were well tolerated by experimental animals with high safety margins than the reference drug meloxicam.