酮洛芬丹皮酚酯及其类似物的合成及抗炎活性研究

目的 合成5种酮洛芬酯类化合物,并研究其抗炎活性和胃肠道不良反应。方法 以丹皮酚及结构类似物和酮洛芬为原料,通过碳二亚胺法合成5种化合物;采用二甲苯致小鼠耳廓肿胀模型和角叉菜胶致大鼠足趾肿胀试验对化合物抗炎活性做了初步的药理学筛选;同时考察化合物对胃肠道不良反应的影响。结果 化合物的结构经¹H-NMR及MS得到确证;5个目标化合物均能显著地减轻小鼠的耳肿胀和大鼠的足趾肿胀程度,与其相应的阳性和阴性对照组相比,都具有良好的抗炎效果;同时,5个目标化合物对胃肠损伤面积明显小于阳性组和阴性组,能够明显地减轻胃肠道的不良反应。结论 合成了5种酮洛芬酯类化合物;抗炎活性均明显强于酮洛芬;且对胃肠道的不良反应明显地减轻。     

New thiazolidinyl analogs containing pyridine ring: synthesis, biological evaluation and QSAR studies

A series of pyridine derivatives of thiazolidin-4-ones (4a–4o) has been synthesized. Structures of these compounds were established on the basis of elemental analysis, IR, ¹H NMR, ¹³C NMR, and Mass spectral data. All the synthesized compounds have been evaluated for their anti-inflammatory and analgesic effects. The results showed that compound 2-[4-methylphenylimino]-5-(1H-pyridin-2-ylmethylidene)-1,3-thiazolidin-4-one (4d), 2-(2,4-dinitro-phenylhydrazinylidine)-5-(1H-pyridin-2-yl-methylidene)-1,3-thiazolidin-4-one (4h), and 2-[3-nitro-phenylimino]-5-(1H-pyridin-2-yl-methylidene)-1,3-thiazolidin-4-one (4j) exhibited good anti-inflammatory and analgesic activity. Compound 4h was found to be the most active compound of the series with an interesting dual anti-inflammatory and analgesic activity. Docking simulation was performed to position synthesized compounds into the active site of COX-2. The relationships of energy-based docking score with analgesic and anti-inflammatory activities were also investigated by linear regression method. The QSAR models with R ² of 0.621 and 0.740 were developed for analgesic and anti-inflammatory activities, respectively.     

Synthesis of new thiazolo[3,2-b][1,2,4]triazole-6(5H)-one derivatives as potent analgesic and anti-inflammatory agents

A series of thiazolo[3,2-b][1,2,4]triazole-6(5H)-ones were synthesized and evaluated for their analgesic and anti-inflammatory activities. The structures of these compounds were supported by FT-IR, ¹HNMR, and Mass spectra. All of the final compounds showed potent analgesic activity and the best compound 9d was 2.4 times more potent than mefenamic acid as the reference drug. In addition, most of them showed comparable or better anti-inflammatory activity in comparison with mefenamic acid and indomethacin. Moreover, compounds 9d, 9e, 9g, 9h, 9i, 9k, 9n, and 9o did not exhibit any significant ulcerogenic activity.     

Synthesis,pharmacological and biological screening of some novel pyrimidine derivatives

In the present study a new series of 4-substituted phenyl-6-(pyridin-2-yl)pyrimidin-2-ol (1–9) and 4-substituted phenyl-6-(pyridin-2-yl)pyrimidin-2-thiol (10–18) have been synthesized by cyclizing 3-substituted phenyl-1-(pyridin-2-yl)prop-2-en-1-one with urea/thiourea in the presence of NaOH as base (1a–18a). 3-Substituted phenyl-1-(pyridin-2-yl)prop-2-en-1-one was prepared by condensing 2-acetylpyridine with substituted benzaldehyde in the presence of 20 % NaOH as base. The structures of the newly synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, and mass spectroscopic studies. Newly synthesized compounds were screened for their anti-inflammatory, analgesic, cytotoxic, and antitubercular activities studies. Few of the compounds exhibited excellent anti-inflammatory activities compared to standard drug diclofenac sodium. Some compounds have shown moderate analgesic activities compared to standard drug pentazocine. Also, some compounds have exhibited moderate cytotoxic and antitubercular activities.     

Synthesis,analgesic and anti-inflammatory activities of new methyl-imidazolyl-1,3,4-oxadiazoles and 1,2,4-triazoles

Background

Long-term clinical employment of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with significant side effects including gastrointestinal (GI) lesions and kidney toxicity. In this paper we designed and synthesized new imidazolyl-1,3,4-oxadiazoles and 1,2,4-triazoles by molecular hybridization of previously described anti-inflammatory compounds in the hope of obtaining new safer analgesic and anti-inflammatory agents.

Methods

The target structures were synthesized by preparation of 5-methyl-1H-imidazole-4-carboxylic acid ethyl ester 5. The reaction of hydrazine hydrate with this ester afforded the 5-methyl-1H-imidazole-4-carboxylic acid hydrazide 6 which was converted to target compounds 7-15 according to the known procedures. In silico toxicity risk assessment and drug likeness predictions were done, in order to consider the privileges of the synthesized structures as drug candidates.

Results and discussion

The analgesic and anti-inflammatory profile of the synthesized compounds were evaluated by writhing and carrageenan induced rat paw edema tests respectively. Compounds 8, 9 and 11-13 and 15 were active analgesic agents and compounds 8, 9 and 11-13 showed significant anti-inflammatory response in comparison with control. Compounds 11 and 13 were screened for their ulcerogenic activities and none of them showed significant ulcerogenic activity. The active Compounds 11 and 12 showed the highest drug likeness and drug score.

Conclusions

The analgesic and anti-inflammatory activities of title compounds were comparable to that of standard drug indomethacin with a safer profile of activity. The results revealed that both of oxadiazole and triazole scaffolds can be determined as pharmacophores. The in silico predictions and pharmacological evaluations showed that compounds 11 and 12 can be chosen as lead for further investigations.     

Synthesis and pharmacological evaluation of N-(6-chlorobenzo[d]thiazol-2-yl)hydrazine carboxamide derivatives of benzothiazole

A series of 6-substituted-1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole (6a–g) and 1,3,4-oxadiazole (7a–g, 8) derivatives of benzothiazole were synthesized in satisfactory yield and pharmacologically evaluated for their anti-inflammatory, analgesic, ulcerogenic, and lipid peroxidation activities by known experimental models. All the synthesized compounds were in good agreement with elemental and spectral data. Some of the synthesized compounds have significant anti-inflammatory and analgesic activities. Ulcerogenic and irritative action on the gastrointestinal mucosa, in comparison with standard are low.     

Novel 2-(E)-substituted benzylidene-6-(N-substituted aminomethyl)cyclohexanones and cyclohexanols as analgesic and anti-inflammatory agents

Twenty-two new 2-(E)-substituted benzylidene-6-(N-substituted aminomethyl)cyclohexanones (6a–6j) and cyclohexanols (7a–7l) were designed and synthesized. Target compounds were obtained through Stork enamine, Mannich, and Grignard reactions taking cyclohexanone as starting material. The structures were confirmed by the application of IR, ¹H NMR, MS, and HR-MS data. The analgesic activities were evaluated by acetic acid-induced writhing test and hot plate method. The anti-inflammatory activities were assayed by xylene-induced ear swelling and carrageenan-induced paw edema in mice model. All tested compounds showed analgesic and anti-inflammatory capacities in oral administration. Some compounds (6a, 6c, 6h, 6i, 7c, 7h, and 7i) displayed the moderate analgesic activity compared with positive control ibuprofen, and some compounds (6a, 6b, 6d, 6h, 7a, and 7d) exhibited more anti-inflammatory activity than ibuprofen. Among them, compound 6a could be a potential nonsteroidal anti-inflammatory agent with significant analgesic activities and remarkable anti-inflammatory activities. Further research is being conducted.     

Synthesis, characterization, and biological evaluation of some N-aryl hydrazones and their 2,3-disubstituted-4-thiazolidinone derivatives

A series of 2,3-disubstituted 4-thiazolidinones 6 and 8a-p have been prepared by the cyclo condensation reaction of various substituted N-aryl hydrazones 5 and 7a–p with mercapto acetic acid. The intermediate N-aryl hydrazones 5 and 7a–p were synthesized by the condensation of 2-bromo-5-methoxy benzohydrazide 4 with 2 or various substituted aromatic aldehydes. The new Naphthalene-2-carboxaldehyde 2 has been synthesized by Vilsmeier-Haack reaction of naphthalen-1(2H)-one 1. The key starting compound 2-bromo-5-methoxy benzohydrazide 4 was prepared from methyl 2-bromo-5-methoxybenzoate 3 by the reaction with hydrazine hydrate in alcoholic medium. The formulae of the compounds were confirmed by elemental analyses and their structures were determined based on IR, ¹H-NMR, ¹³C-NMR, ¹³C-NMR-DEPT, and mass spectral data. The newly synthesized compounds were evaluated for their antioxidant, anti-inflammatory, and analgesic activities. The antibacterial activities of the newly synthesized compounds against E. coli ATCC 8739, S. aureus ATCC 6538, P. aeruginosa ATCC 1539, and Bacillus cereus, while the antifungal activities of the compounds against Candida albicans were tested. The acute cytotoxicity data of compounds 7h and 8a are tested and are found to be nontoxic up to 2,500 mg/kg.     

Design and synthesis of niflumic acid-based N-acylhydrazone derivatives as novel anti-inflammatory and analgesic agents

A new series of niflumic acid-based N-acylhydrazone derivatives 5a–p were synthesized and evaluated for their anti-inflammatory and analgesic activities. Most of the compounds have shown anti-inflammatory activity with a moderate-to-excellent activity range (20–80 % reduction in inflammation). Among them, 3-chlorophenyl 5d and 3-pyridyl derivatives 5o exhibited the most potent anti-inflammatory activity relative to niflumic acid as the reference drug (77, 76, and 70 % reduction in inflammation at 1-h postdrug administration, respectively). Also, molecular simplification of niflumic acid through replacing the N-aryl group with N-methyl group produced compounds 6a–f with anti-inflammatory activity in a quite similar manner to those of their parent derivatives. In this subgroup, 4-pyridyl derivative 6f showed the most potent anti-inflammatory activity relative to niflumic acid (80 % reduction in inflammation at 1-h postdrug administration). The compounds with highest anti-inflammatory activity were subjected to analgesic assays and showed moderate-to-excellent analgesic activities. The compound 5j, 4-methoxy derivative, exhibited the highest analgesic activity relative to niflumic acid (97 and 68 % activity, respectively).     

Amino acid conjugates of 2-mercaptobenzimidazole provide better anti-inflammatory pharmacology and improved toxicity profile

Benzimidazole is an important pharmacophore for clinically active drugs against inflammation and treatment of pain, however, it is associated with gastrointestinal side effects. Here we synthesized benzimidazole based agents with significant analgesic/anti-inflammatory potential but with less gastrointestinal adverse effects. In this study, we synthesized novel, orally bioavailable 2-mercaptobenzimidazole amino acid conjugates ( 4a–4o ) and screened them for analgesic, anti-inflammatory and gastro-protective effects. The synthesized 2-mercaptbenzimidazole derivatives were characterized for their structure using FTIR, ¹H NMR and ¹³C NMR spectroscopic techniques. The 2-mercaptobenzimidazole amino acid conjugates have found to possess potent analgesic, anti-inflammatory and gastroprotective activities, particularly with compound 4j and 4k . Most of the compounds exhibited remarkable anti-ulcer and antisecretory effects. Molecular docking studies were carried out to study the binding affinities and interactions of the synthesized compounds with target proteins COX-2 (PDB ID: 3LN1) and H⁺/K⁺-ATPase (PDB ID: 5Y0B). Our results support the clinical promise of these newly synthesized 2-mercaptobezimidazol conjugates as a component of therapeutic strategies for inflammation and analgesia, for which the gastric side effects are always a major limitation.     

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, characterization and their anticonvulsant, anti-inflammatory studies of some novel chromeno oxadiazoles

In this study, a series of new 1,2,4-oxadiazole derivatives containing 3,4-dihydro-2H-chromen-2-amine moiety were synthesized by efficient microwave reaction of 2-amino-N′-hydroxychroman-3-carboxamidine and suitable aldehyde. Structures of all the synthesized compounds were confirmed by spectral studies and C, H, N analyses. Newly synthesized compounds were screened for their anticonvulsant and anti-inflammatory properties. Few of the compounds exhibited excellent anticonvulsant activity as compared to the standard drug Diazepam. Also compounds have exhibited moderate anti-inflammatory activity as compared to the standard drug Diclofenac sodium.     

Synthesis,Anti-Inflammatory,and Ulcerogenicity Studies of Novel Substituted and Fused Pyrazolo[3,4-d]pyrimidin-4-ones

In the present investigation, some new pyrazolo[3,4-d]pyrimidin-4(5H)-one derivatives (7–12) as well as fused pyrazolo[3′,4′:4,5]pyrimido[1,2-b]pyridazin-4(1H)-one (14–16) and 7,8,9,10-tetrahydropyrazolo[3′,4′:4,5]pyrimido[1,2-b]-cinnolin-4(1H)-one (17) ring systems were synthesized using the starting compound 5-amino-6-methyl-1-phenyl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one (5). The structures of the newly synthesized compounds were elucidated by IR, ¹H NMR, ¹³C NMR, mass spectroscopy, and elemental analysis. The theoretical calculation of their lipophilicity as C log P was performed. The anti-inflammatory activity of all newly synthesized compounds was evaluated using the carrageenan-induced paw edema test in rats using indomethacin as the reference drug. Ulcer indices for the most active compounds were calculated. Seven compounds (10b, 11a–f) showed consistently good anti-inflammatory activity. In particular, 5-{[4-(4-bromophenyl)-3-(4-chlorophenyl)-1,3-thiazol-2(3H)-ylidene]amino}-6-methyl-1-phenyl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one (11e) and its 3,4-bis(4-chlorophenyl) analog (11f) were found to be the most effective among the other derivatives, showing activity comparable to that of indomethacin with minimal ulcerogenic effects. Correlation of the biological data of the active compounds with their theoretically calculated C log P values revealed that lipophilicity influences the biological response.     

Synthesis of new oxadiazole derivatives as anti-inflammatory, analgesic, and antimicrobial agents

In search of pharmalogically active molecules in the class of oxadiazoles, the present article deals with the synthesis of 5-(5′-fluoro-2′-methoxybiphenyl-3-yl)-1,3,4-oxadiazol-2(3H)-one 2 from its hydrazide analog 1. The compound 2 was regioselectively N-alkylated with alkyl halides and produced the compounds 3a–f. Compound 3f was further functionalized with substituted benzenesulfonyl chlorides to give compounds 3g–j. The synthesized compounds were characterized by elemental and spectral analysis. Newly synthesized compounds were tested for their in vivo anti-inflammatory, analgesic, and in vitro antimicrobial activities. The compounds 3a–c were found to have promising anti-inflammatory and analgesic activities. Compounds 3b, 3f, and 3g showed significant antibacterial and antifungal activities.     

Synthesis and antibacterial activity of some new hydrazones

New hydrazone derivatives were synthesized by the condensation of some selected heteroaromatic hydrazines with appropriate aromatic ketones at high temperature (100 °C). The structures of the synthesized compounds were established by elemental (CHN) and spectral (IR, ¹HNMR, and Mass) analysis. The synthesized compounds were screened for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Proteus mirabilis) activities, which reveal that all the compounds possess activity against all the tested organisms.     

Synthesis of 2-(aryl)-5-(arylidene)-4-thiazolidinone derivatives with potential analgesic and anti-inflammatory activity

A series of novel N-[5-(arylidene)-2-(aryl)-4-oxo-thiazolidin-3-yl]-4-biphenylcarboxamide derivatives was synthesized and evaluated for analgesic and anti-inflammatory activity. In this study, biphenyl-4-carboxylic acid hydrazide was converted to the corresponding aryl hydrazones using aryl aldehydes in the presence of catalytic amount of glacial acetic acid. The aryl hydrazones on reaction with thioglycolic acid in the presence of anhydrous zinc chloride yielded N-[2-(aryl)-4-oxo-thiazolidin-3-yl]-4-biphenylcarboxamide which further on reaction with aromatic aldehydes in the presence of anhydrous sodium acetate and glacial acetic acid furnished the title compounds. All compound exhibited anti-inflammatory activity at the dose 10?mg/kg. The structures of all these newly synthesized compounds were confirmed by their elemental analyses (C, H, N) and spectral data (IR and ¹H NMR).     

Design,synthesis of new chiral fluorine-containing β-hydroxysulfonamides from natural amino acids and study of their anti-inflammatory and analgesic activities

A series of new chiral fluorine-containing β-hydroxysulfonamides were conveniently synthesized in three steps, starting from natural L-amino acids, and evaluated for their anti-inflammatory and analgesic activities. The structures of these compounds were supported by FT-IR, ¹H, ¹³C and ¹⁹F NMR, elemental analysis and HRMS. Among the tested compounds, 4c, 4g and 4h exhibited promising anti-inflammatory activity. Moreover, compound 4h showed a significant analgesic activity. The structure–activity relationships of selected compounds were discussed.     

血小板活化因子受体拮抗剂——芳氨酮类化合物的合成及其抗炎活性

以取代亚苄基丙酮和二级胺盐酸盐经Mannich反应合成了一系列具有抗炎活性的芳氨酮类化合物，其结构经¹H NMR、MS、元素分析或HRMS确证。同时测定了所合成化合物对血小板活化因子(PAF)引起的大鼠胸腔多形核白细胞β-葡糖苷酸酶释放的抑制作用，初步药理实验结果表明，大部分芳氨酮类(MA)化合物对PAF引起的大鼠胸腔多形核白细胞β-葡糖苷酸酶的释放有明显的抑制作用，其中化合物MA12、MA13、MA18、MA21和MA33的抑制活性较强。提示化合物可通过抑制β-葡糖苷酸酶释放发挥抗炎作用，可能是潜在的PAF受体拮抗剂。     

Synthesis and Biological Activity of New [1,3]Thiazolo[4,5-d]pyridazin-4(5H)-ones

A series of novel 2-(N-pyrrolidino, N-piperidino or N-morpholino)-7-phenyl(α-furoyl or α-thienyl)-[1,3]thiazolo[4,5-d]pyridazinones 10a–c, 14–16a,b was synthesized in 78–87% yields via the reaction of methyl 5-benzoyl(α-furoyl or α-thienyl)-2-aminosubstituted-thiazol-4-carboxylates 9a–c, 13a–e with hydrazine. These new compounds have been tested for their in vivo analgesic and anti-inflammatory activities. All compounds have been characterized by ¹H-NMR, ¹³C-NMR spectroscopy, and liquid chromatography–mass spectrometry.