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.     

3,4-二氢吡咯[1,2-a]吡嗪-1-酮衍生物的合成及抗炎镇痛作用

目的研究(2H)-2-环己基-3,4-二氢吡咯[1,2-a]吡嗪-1-酮衍生物抗炎镇痛作用的构效关系。方法以2-吡咯甲酸甲酯为原料,经取代、环合,制备(2H)-2-环己基-3,4-二氢吡咯[1,2-a]吡嗪-1-酮(3);通过Friedel-Crafts酰基化反应,制得其6-酰基衍生物4a~4j。用小鼠测试了所合成化合物的抗炎和镇痛活性。结果与结论合成了10个未见文献报道的新化合物4a~4j,其结构经MS1、H-NMR分析确证。抗炎镇痛试验表明,有些化合物具有明显的抗炎和/或镇痛作用,其中化合物4d的活性与对照药布洛芬相当。     

Synthesis and evaluation of the analgesic and anti-inflammatory activity of new 3(2H)-pyridazinone derivatives

A series of 6-substituted-3(2H)-pyridazinone derivatives were synthesized and evaluated for analgesic and anti-inflammatory activities. The structures of these new pyridazinone derivatives were confirmed by their IR, 1H-NMR spectra and elementary analysis. Analgesic and anti-inflammatory activities of the title compounds have been evaluated. Four of the ten tested compounds possessed significant analgesic effects in the phenylbenzoquinone-induced writhing test (PBQ test). The most active derivatives 8a, 8b, 8d, 8e were void of gastric ulcerogenic effect or acute toxicity at the maximal dose (200 mg/kg p.o.). In the carrageenan-induced paw edema model, compound 8d (6- [4- (2-fluorophenyl) piperazin-1-yl]-3(2H)-pyridazinone) showed anti-inflammatory activity similar to that of the standard drug indometacin (CAS 53-86-1). A significant dependence of the anti-inflammatory effect on the substituents was observed; The pharmacological study of these compounds confirms that modification of the chemical group at position 6 of the 3(2H)-pyridazinone ring influences analgesic and anti-inflammatory activities.     

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 and anticoagulant activities of substituted 2,4-diketochromans, biscoumarins, and chromanocoumarins

Different substituted 2,4-diketochromans, biscoumarins, and chromanocoumarins are the final products when 4-hydroxycoumarin and aromatic aldehydes containing hydroxyl group in o-, m,- or p-position condense in boiling ethanol. We synthesized 14 compounds. Three of them are described for the first time. The X-ray crystal structure analysis of 3-[6-oxo-(6H, 7H)-benzopyrano[4,3-b]benzopyran-7-yl]-4-hydroxy-2H-1-benzopyran-2-one 1 confirmed the structure of this compound. Acute toxicity studies of the compounds were performed on mice by oral and intraperitoneal administration. A comparative pharmacological study of the in vivo anticoagulant effect of the derivatives with respect to warfarin showed that the synthesized compounds have different anticoagulant activities. The most prospective compounds are 3-(3'-hydroxybenzylidene)-2,4-diketochroman 4 and 3,3'-(2-pyridylmethylene)-bis-4-hydroxy-2H-1-benzopyran-2-one 11 with low toxicity and dose-dependent anticoagulant activity in vivo.     

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, acute toxicity, and analgesic activity of new derivatives of pyrrole

Ten pyrrole derivatives (including six new compounds) were synthesized and evaluated as potential platform for analgesic agents' development. Acute intraperitoneal toxicity and analgesic activity studies (acetic acid writhing test) were performed on mice with acetylsalicylic acid used as a reference substance. Products 3c, 3d, 3e, and 3h exhibited a dose-dependent activity demonstrating 1.5 to 2.5-fold better protections than the reference. The most prospective compounds comprised salicylic acid moieties, whose 4-substituted derivatives were related to lower acute toxicity and considerable activity. 4-[3-(Ethoxycarbonyl)-2-methyl-5-(3,4-dimethoxy-phenyl)-1H-pyrrol-1-yl]-2-hydroxy-benzoic acid 3c was pointed out as the most prospective substance due to its lower acute toxicity (378 mg/kg body weight, intraperitoneally) and highest analgesic activity (up to 89.3% protection) in a dose range of 1/10 to 1/40 parts of LD(50).     

Synthesis and antinociceptive activity of (5-chloro-2(3H)-benzothiazolon-3-yl)propanamide derivatives

Ten new (5-chloro-2(3H)-benzothiazolon-3-yl)propanamide derivatives have been synthesized. The compounds were tested for antinociceptive activity by tail clip, tail flick, hot plate and writhing test by using aspirin and dipyrone as standards. Among these compounds, 1-[3-(5-chloro-2(3H)-benzothiazolon-3-yl)-propanoyl]-4-(4-chlorophenyl)piperazine (11e) has been found to be significantly more active than the other compounds synthesized as well as the standards in all tests.     

黄酮衍生物的合成及其抗炎活性研究

目的 设计合成一系列黄酮衍生物,并考察其抗炎活性。方法 采用Baker-Venkataraman反应合成单羟基取代的黄酮,进而经Williamson反应合成黄酮衍生物;以布洛芬为阳性对照药,采用巴豆油致小鼠耳肿胀实验对5个目标化合物（1a、1c、1d、2a、2c）的抗炎活性进行了评价。结果与结论 以2’,5’-二羟基苯乙酮或2’,4’-二羟基苯乙酮为原料,合成了12个未见文献报道的新化合物,其结构经核磁共振氢谱、高分辨质谱及红外光谱确证。初步的药理筛选结果表明化合物6-[2-(4-吗啉基)乙氧基]黄酮(1a)和2’-氟-7-(2-二甲氨基甲酰甲氧基)黄酮(2c)具有潜在的抗炎活性。     

Synthesis, Analgesic, and Anti-Inflammatory Activities of [6-(3,5-Dimethyl-4-Chloropyrazole-1-yl)-3(2H)-Pyridazinon-2-yl]Acetamides

A series of structurally diverse amide derivatives of [6-(3,5-dimethyl-4-chloro-pyrazole-1-yl)-3(2H)-pyridazinone-2-yl]acetic acid were prepared and tested for their in vivo analgesic and anti-inflammatory activity by using p-benzoquinone-induced writhing test and carrageenan-induced hind paw edema model, respectively. The analgesic and anti-inflammatory activity of the compounds, 7c, 7d and 7k were found to be equipotent to aspirin (as an analgesic) and indometacin (as an anti-inflammatory drug), respectively. The other amide derivatives generally resulted in lower activity on comparision with reference compounds.     

Non-carboxylic analogues of naproxen: design, synthesis, and pharmacological evaluation of some 1,3,4-oxadiazole/thiadiazole and 1,2,4-triazole derivatives

A series of substituted 1,3,4-oxadiazole (2-7 and 14-19), 1,2,4-triazole (20-25), and 1,3,4-thiadiazole (26-31) derivatives of naproxen have been synthesized by cyclization of 2-(6-methoxy-2-naphthyl)propanoic acid hydrazide 1 and N(1)[2-(6-methoxy-2-naphthyl) propanoyl]-N(4)-alkyl/aryl-thiosemicarbazides (8-13) under various reaction conditions. All the compounds were screened for their anti-inflammatory activity by carrageenan-induced rat paw edema test method. Compounds showing high anti-inflammatory activity were also tested for their analgesic, ulcerogenic, and lipid peroxidation. Few of the synthesized compounds showed significant anti-inflammatory and analgesic activities along with reduced ulcerogenic effect and lipid peroxidation.     

Synthesis of new Mannich bases of arylpyridazinones as analgesic and anti-inflammatory agents

A series of 2-[[4-(substituted-phenyl/ benzyl)-1-piperazinyllmethyl]-6-(4-methoxyphenyl)-3(2H)pyridazinone derivatives was prepared and examined for analgesic and anti-inflammatory activities. The structures of these new pyridazinone derivatives were confirmed by their IR and 1H-NMR spectra and elementary analysis. Among the compounds prepared, 2-[[4-(4-fluorophenyl)-1-piperazinyl]methyl]-6-(4-methoxyphenyl)-3(2H)pyridazinone IVe was found to be a most promising analgesic and anti-inflammatory agent. Compound IVe showed more potent analgesic activity than acetylsalicyclic acid in the phenylbenzoquinone-induced writhing test. Also IVe showed anti-inflammatory activity comparable to that of the standard compound indometacin against the carrageenan-induced paw edema. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed a gastric ulcerogenic effect compared with reference nonsteroidal anti-inflammatory drugs. On the basis of the available data, the structure-activity relationship of the series of 2-[[4-(substituted-phenyl/benzyl)-1-piperazinyl]methyl]-6-(4-methoxyphenyl)-3(2H) pyridazinones is also discussed.     

Synthesis of amide derivatives of [6-(3,5-dimethylpyrazol-1-yl)-3(2H)-pyridazinone-2-yl] acetic acid and their analgesic and anti-inflammatory properties

A series of structurally different amide derivatives of [6-(3,5-dimethylpyrazol-1-yl)-3(2H)-pyridazinone-2-yl]acetic acid were prepared and tested for their analgesic and anti-inflammatory activity in vivo by using p-benzoquinone-induced writhing test and carrageenan-induced hind paw edema model, respectively. The analgesic and anti-inflammatory activity of the compounds 6a and 6b were equipotent, and 6m was more potent than acetyl salicylic acid (CAS 50-78-2) as an analgesic and indometacin (CAS 53-86-1) as an anti-inflammatory drug, respectively. The other amide derivatives and parent carboxylic acid molecule generally resulted in lower activity to reference compounds. Inhibitor activity of the active compounds on cyclooxygenase isoforms was also investigated by using in vitro COX inhibitor screening assay and found that these derivatives did not exert their analgesic and anti-inflammatory activities through COX inhibition and that other mechanisms might be involved.     

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 N-substituted 4,6-dioxo-imidazo[3,4-c] thiazoles and their analgesic activity in mice

A new series of N-substituted dioxo-imidazo[3,4-c]thiazoles have been prepared and evaluated for their analgesic activity. The structures of these new derivatives were confirmed by lR, 1H NMR and 13C NMR spectra, and by elemental analysis. When administered intraperitoneally to mice all derivatives were devoid of any toxic effect, even at the high dose of 800 mg kg(-1). In the phenylbenzoquinone-induced abdominal constriction test in mice, eight of the nine synthesized compounds exhibited significant antinociceptive properties with ED50 values (50% effective dose) ranging from 46.7 to 104.7 mg kg(-1) intraperitoneally. Further investigation demonstrated that analgesic activity of the most effective derivatives 5e and 5f partly involved opioidergic and/or noradrenergic pathways.     

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.     

3-芳基-2-甲基-1-吡咯并[1,2-a]吡嗪酮类衍生物的合成和抗炎镇痛作用

目的研究3-芳基-2-甲基-1-吡咯并[1,2-a]吡嗪酮(2)类化合物抗炎镇痛作用的构效关系.方法通过吡咯-2-甲酸甲酯与α-溴代芳基乙酮的烃基化反应,制得1-(2-氧代-2-芳基)乙基吡咯-2-甲酸甲酯(4),4与甲胺反应经过环合直接生成目的化合物2;用小鼠测试了所合成化合物的抗炎镇痛活性.结果与结论合成了15个目标化合物;小鼠试验表明,一些所合成的化合物具有明显的抗炎和/或镇痛作用,其中化合物2o的作用活性与阳性对照药布洛芬相似.     

Synthesis and evaluation of analgesic, anti-inflammatory and antioxidant activities of new 6-acyl-3-alkyl-5-methyl-2(3H)-benzoxazolones

A new series of 6-acyl-3-alkyl-5-methyl-2(3H)-benzoxazolones have been obtained starting from 5-methyl-2(3H)-benzoxazolone. All the compounds have been characterized by IR, 1H-NMR and mass spectroscopy. The new compounds were screened for analgesic and anti-inflammatory activities and ulcerogenic effect. The in vitro antioxidant capacity of the synthesized compounds were tested by the nitric oxide radical scavenging assay. Most of the compounds showed antiinflammatory activity. Among them, 3-[4-(4-fluorophenyl)piperazinomethyl] -6-(3-chlorobenzoyl)-5-methyl-2(3H)-benzoxazolone (3j) was found more potent than the reference drug indometacin (CAS 53-86-1) with 41.66% decrease in edema. Compared with the control, some of the compounds exhibited analgesic effects. Similar to the anti-inflammatory activity results, compound 3j showed the highest analgesic profile with 48.56% inhibition. No active hemorragic focus was observed in the microscopic evaluation in the ulcerogenic effect studies of the tested compounds. 6-(3-Chlorobenzoyl)-5-methyl-2(3H)-benzoxazolone (2b) and 3-[4-(4-fluorophenyl-piperazino)methyl]-6-(3-chlorobenzoyl)-5-methyl-2(3H)-benzoxazolone (3j) showed nearly maximum antioxidant activity compared to ascorbic acid (CAS 50-81-7) with IC50 values of 27.6 and 30.1 microg/mL, respectively.     

Synthesis,molecular properties,toxicity and biological evaluation of some new substituted imidazolidine derivatives in search of potent anti-inflammatory agents

The aim of this study was to design and synthesize pharmaceutical agents containing imidazolidine heterocyclic ring in the hope of developing potent, safe and orally active anti-inflammatory agents. A number of substituted-imidazolidine derivatives (3a–k) were synthesized starting from ethylene diamine and aromatic aldehydes. The imidazolidine derivatives (3a–k) were investigated for their anticipated anti-inflammatory, and analgesic activity in Wistar albino rats and Swiss albino mice, respectively. Bioactivity score, molecular and pharmacokinetic properties of the imidazolidine derivatives were calculated by online computer software programs viz. Molinspiration and Osiris property explorer. The results of biological testing indicated that among the synthesized compounds only three imidazolidine derivatives namely 4-[1,3-Bis(2,6-dichlorobenzyl)-2-imidazolidinyl]phenyl-diethylamine (3g), 4-[1,3-Bis(3-hydroxy-4-methoxybenzyl)-2-imidazolidinyl]phenyl-diethylamine (3i) and 4-(1,3-Bis(4-methoxybenzyl)-4-methylimidazolidin-2-yl)-phenyl-diethylamine (3j) possess promising anti-inflammatory and analgesic actions. Additionally these derivatives displayed superior GI safety profile (low severity index) with respect to the positive control, Indomethacin. All synthesized compounds showed promising bioactivity score for drug targets by Molinspiration software. Almost all the compounds were predicted to have very low toxicity risk by Osiris online software. Compound number (3i) emerged as a potential candidate for further research as it obeyed Lipinski’s rule of five for drug likeness, exhibited promising biological activity in-vivo and showed no risk of toxicity in computer aided screening.     

Synthesis of new pyrroles of potential anti-inflammatory activity

We herein disclose a series of novel pyrrole derivatives 1-4 and pyrrolo[2,3-d]pyrimidine derivatives 6-11 as novel potent anti-inflammatory compounds. The structures were confirmed by IR, (1) H-NMR, and MS. Some newly synthesized compounds were examined for their in-vivo anti-inflammatory activity. Several derivatives showed a promising anti-inflammatory activity compared to ibuprofen. In this paper, we examine and discuss the structure-activity relationships and anti-inflammatory activities of these compounds.