Anti-inflammatory activity of substituted 1,3,4-oxadiazoles

Various 2-(4-biphenoxymethyl)-5-arylamino-1,3,4-oxadiazoles were synthesized by cyclization of the corresponding 1-(4-biphenoxyacetyl)-4-substituted thiosemicarbazides. These compounds were characterized by their elemental analyses and infrared, mass, and nuclear magnetic resonance spectral data. All substituted thiosemicarbazides (100 mg/kg, ip) and cyclized substituted oxadiazoles (100 mg/kg, ip) possessed anti-inflammatory activity, as reflected by their ability to provide protection against carrageenin-induced edema in the rat paw which ranged from 28 to 68% and 36 to 76%, respectively. Cyclization of the substituted thiosemicarbazides, in general, resulted in an increase in the anti-inflammatory activity of their corresponding substituted oxadiazoles, with the exception of those containing 2,4-dimethyl and 3,4-dimethyl substituents in their molecular structure. Hydrocortisone (10 mg/kg, ip) and oxyphenbutazone (40 mg/kg, ip) were used as the standard reference drugs and these provided 45 and 53% protection, respectively. All compounds (1 mM) possessed antiproteolytic activity and the in vitro inhibition of trypsin-induced hydrolysis of bovine serum albumin ranged from 13 to 75% for substituted thiosemicarbazides and 39 to 70% for substituted oxadiazoles. There was no relationship between the anti-inflammatory activity of substituted thiosemicarbazides and substituted oxadiazoles and their antiproteolytic effectiveness. The low toxicity of these compounds was reflected by their high approximate LD50 values, ranging from 500 to 1000 mg/kg.     

Selective chiral inhibitors of 5-lipoxygenase with anti-inflammatory activity

The studies described here, using enantiomers of an optically-active methoxy alkyl thiazole ICI216800 (1-methoxy-6-(naphth-2-yl-methoxyl)-1- (thiazol-2-yl)indane), provide unequivocal evidence for a specific, chiral interaction with 5-lipoxygenase. In accordance with their biochemical efficacy these compounds also demonstrate enantio-specific anti-inflammatory activity in a leukotriene-mediated model of inflammation. This is the first class of compounds for which 5-lipoxygenase inhibition and anti-inflammatory activity have been shown to be mediated via a specific chiral interaction.     

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.     

Synthesis and anti-inflammatory activity of fluorinated phenyl styryl ketones and N-phenyl-5-substituted aryl-3-p-(fluorophenyl) pyrazolins and pyrazoles.

Various N-phenyl-5-substituted aryl-3-p-(fluorophenyl) pyrazolins and pyrazoles were synthesized by cyclization of the corresponding 4-(fluorophenyl) styryl and 4-(fluorophenyl) dibromostyryl ketones. These compounds were characterized by elemental analysis and UV, infrared, and nuclear magnetic spectral data. All substituted p-(fluorophenyl) styryl ketones [250 mg/kg orally (po)] possessed anti-inflammatory activity, as reflected by their ability to provide protection (51-70%) against carrageenin-induced edema in rat paw. Indomethacin (10 mg/kg, po) and dehydrozingerone (70 mg/kg, po), used as standard reference drugs, provided 97 and 60% protection, respectively. All compounds (0.20 mM) showed ability to denature bovine serum albumin, as observed in in vitro inhibition studies. Inhibition ranged from 7 to 59% for substituted p-(fluorophenyl) styryl ketones and from 12 to 21% for pyrazoles. No correlation was found between the anti-inflammatory activity of p-(fluorophenyl) styryl ketones or substituted pyrazoles and their effectiveness at inhibiting bovine serum albumin denaturation. The low toxicity of p-(fluorophenyl) styryl ketones was reflected by the dose that was lethal in 50% of the cases tested (2000-2500 mg/kg).     

2-（E）-亚苄基-5-芳氨基甲基环戊醇类化合物的合成及其抗炎活性研究

目的设计合成2-（E）-亚苄基-5-芳氨基甲基环戊醇类化合物，并对其抗炎活性进行初步的评价。方法以环戊酮为起始原料，通过Stork烯胺反应、Mannich缩合反应、胺交换反应和选择性还原制备目标化合物；以二甲苯致小鼠耳肿胀模型测试目标化合物的抗炎活性。结果共合成16个新化合物，其结构经^1H-NMR和MS谱确证。结论初步药理实验结果显示，4个目标化合物具有较强的抗炎活性。     

Synthesis of some novel oxadiazole and oxadiazoline analogues for their antiinflammatory activity

The search for newer non-steroidal antiinflammatory drugs (NSAIDs) and the importance of oxadiazoles as antiinflammatory agents prompted us to undertake the synthesis of some novel oxadiazole and related analogues with unreported antiinflammatory activities. The antiinflammatory potential of the compounds was investigated using the carrageenan-induced rat paw edema method and cotton pellet-induced granuloma method. Some compounds demonstrated marked antiinflammatory activities. The antiinflammatory activity of oxadiazoles at doses of 100 mg/kg was shown by their ability to provide 28-55%, 21-36%, and 27-49% protection against carrageenan-induced rat paw edema, moist cotton pellet-induced, and dry cotton pellet-induced granuloma, respectively. On the other hand, the antiinflammatory properties of oxadiazolines at doses of 100 mg/kg was reflected by their ability to provide 15-47%, 22-39%, and 23-47% protection against carrageenan-induced rat paw edema, moist cotton pellet-induced, and dry cotton pellet-induced granuloma, respectively. Structure-activity relationships among synthesized compounds were also studied.     

3D-QSAR and preliminary evaluation of anti-inflammatory activity of series of N-pyrrolylcarboxylic acids

The present study focuses on development of new potential inhibitors of cyclooxygenase-2 (COX-2): series of N-pyrrolylcarboxylic acids. 3D-QSAR (Quantitative Structure-Activity Relationship) CoMFA (Comparative Molecular Field Analysis) and CoMSIA (Comparative Molecular Similarity Index Analysis) models for predicting inhibitory activities against COX-1 and COX-2 as well as for evaluating in vivo anti-inflammatory activity were obtained and used for preliminary screening of new anti-inflammatory N-pyrrolylcarboxylic acids. Nine compounds were selected for in vivo testing and evaluated for their potency to decrease carrageenin-induced edema in rats. The compounds were applied i.p. at doses 20 mg/kg and 40 mg/kg and p.o. at doses 10 mg/kg and 40 mg/kg. Six compounds showed more than 70% protection of the edema. Indomethacin (2 mg/kg i.p.), used as a reference drug, possessed 54% anti-inflammatory activity under similar experimental conditions.     

Synthesis and evaluation of analgesic,anti-inflammatory and antimicrobial activities of 6-acyl-3-piperazinomethyl-2-benzoxazolinones

In this study, 16 new 6-difluorobenzoyl-3-piperazinomethyl-2-benzoxazolinones were synthesized by Mannich reaction. Their chemical structures were proven by IR, 1H-NMR and elemental analysis. The compounds were screened for their analgesic and anti-inflammatory activities. A modified Koster test, using acetylsalicylic acid (ASA, CAS 50-78-2) as the reference drug, was used to assess analgesic activity. The anti-inflammatory activity was evaluated by the carrageenan induced hind-paw oedema test. The analgesic activities of all compounds were higher than their anti-inflammatory activities and therefore the prominent analgesic actions of the compounds are thought to be due to a central effect. The microbiological effects of the compounds were evaluated in vitro against various pathogenic fungi and bacteria using the microdilution method. Most of the compounds were found to be inactive against bacteria and fungi. One of the compounds (31) possessed considerable analgesic activity as well as moderate antibacterial activity against S. aureus. Another compound (3m) showed analgesic and antifungal activities comparable to those of ASA and fluconazole (CAS 86386-73-4), respectively.     

Synthesis and anti-inflammatory activity of 2-substituted-((N, N-disubstituted)-1, 3-benzoxazole)-5-carboxamides

A series of 2-substituted-((N, N-disubstituted)-1, 3-benzoxazole)-5-carboxamides derivatives were synthesized by the reaction of 2-substituted-5-carbomethoxy benzoxazole with different secondary amines. The newly synthesized compounds were characterized on the basis of spectral (FT-IR, 1H NMR, MS) & elemental analysis. All these compounds were screened for anti-inflammatory activity using carrageenan induced rat paw edema method. All of these compounds exhibited significant activity. Among the tested compounds Ve, Vg, Vf and Va were considered to have potent anti-inflammatory activity and was comparable with standard.     

Substituted thiazolidones: selective inhibition of nicotinamide adenine dinucleotide-dependent oxidations and evaluation of their CNS activity.

Eight 2-arylimino-3-(3-N-morpholinopropyl) thiazolid-4-ones were synthesized from the corresponding 1-aryl-3-(3-N-morpholinopropyl) thiocarbamides, characterized, and tested for their effects on the cellular respiratory activity of rat brain homogenates. All substituted 4-thiazolidones selectively inhibited nicotinamide adenine dinucleotide (NAD)-dependent oxidations of pyruvate, citrate, DL-isocitrate, alpha-ketoglutarate, malate, beta-hydroxybutyrate, L-glutamate, and NADH, while the NAD-independent oxidation of succinate remained unaltered. All thiazolidones possessed some degree of anticonvulsant activity against pentylenetetrazol-induced convulsions, and the protection afforded by these compounds at a dose of 100 mg/kg ranged from 30 to 80%. The low toxicity possessed by most of these thiazolidones was reflected by their approximate LD-50 values from 300 mg/kg to greater than 1000 mg/kg. In the present study, the anticonvulsant activity possessed by these substituted 4-thiazolidones was unrelated to their ability to inhibit selectively the NAD-dependent oxidations by rat brain homogenates. These thiazolidones exhibited depression of the CNS activity which, in some cases, was associated with the increase in respiration. All thiazolidones potentiated pentobarbital (sodium) sleeping time in mice when administered in a dose of 100 mg/kg.     

Anti-inflammatory activity of quinazolinoformazans

Eight substituted quinazolonoformazans were synthesized and evaluated for anti-inflammatory activity. The degree of protection provided by seven of these compounds, at a dose of 100 mg/kg, po, against carrageenin-induced edema in rat paw ranged from 26 to 57%. The four active substituted quinazolonoformazans (1, 2, 6, 8), on further evaluation for antiwrithmogenic activity, provided 10-80% protection against the aconitine-induced writhing response in mice. The ulcerogenic liabilities of two of the most active compounds were also determined. The doses producing ulcers in 50% of the treated rats (UD50) were 155 and 260 mg/kg, ip, for 2 and 8, respectively. The low toxicities possessed by these substituted quinazolonoformazans were indicated by their LD50 values which ranged from 600 to 1300 mg/kg, ip, in mice.     

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.     

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。     

4-sulphamoylphenyl semicarbazones with anticonvulsant activity

A series of 4-sulphamoylphenyl semicarbazone derivatives were prepared starting from sulphanilamide and screened for anticonvulsant activity. The results indicated that greater protection was obtained in the maximal electroshock screen (MES) and subcutaneous strychnine (scSTY) than the subcutaneous pentylenetetrazole (scPTZ) tests. All the compounds showed low neurotoxicity when compared to the clinically used drugs. Compounds with substituted acetophenone (8-11) showed good activity in the rat oral MES screen. Seven compounds (6, 8-10, 12, 14 and 15) exhibited anticonvulsant activity greater than sodium valproate. Among the new derivatives evaluated, compound 10 emerged as the most active compound as indicated by its protection in the MES and scSTY screens and with low neurotoxicity. Seven compounds possessed sedative-hypnotic activity.     

Inhibition of amyloidogenesis by nonsteroidal anti-inflammatory drugs and their hybrid nitrates

Poor blood-brain barrier penetration of nonsteroidal anti-inflammatory drugs (NSAIDs) has been blamed for the failure of the selective amyloid lowering agent (SALA) R-flurbiprofen in phase 3 clinical trials for Alzheimer's disease (AD). NO-donor NSAIDs (NO-NSAIDs) provide an alternative, gastric-sparing approach to NSAID SALAs, which may improve bioavailability. NSAID analogues were studied for anti-inflammatory activity and for SALA activity in N2a neuronal cells transfected with human amyloid precursor protein (APP). Flurbiprofen (1) analogues were obtained with enhanced anti-inflammatory and antiamyloidogenic properties compared to 1, however, esterification led to elevated Aβ(1-42) levels. Hybrid nitrate prodrugs possessed superior anti-inflammatory activity and reduced toxicity relative to the parent NSAIDs, including clinical candidate CHF5074. Although hybrid nitrates elevated Aβ(1-42) at higher concentration, SALA activity was observed at low concentrations (≤1 μM): both Aβ(1-42) and the ratio of Aβ(1-42)/Aβ(1-40) were lowered. This biphasic SALA activity was attributed to the intact nitrate drug. For several compounds, the selective modulation of amyloidogenesis was tested using an immunoprecipitation MALDI-TOF approach. These data support the development of NO-NSAIDs as an alternative approach toward a clinically useful SALA.     

Anticonvulsant activity and selective inhibition of nicotinamide adenine dinucleotide-dependent oxidations by 10-(2-arylimino-3-acetylamino-4-thiazolidonyl) phenothiazines.

Several Several 10-(1-acetyl-4-arylthiosemicarbazido) phenothiazines and their corresponding cyclized 10-(2-arylimino-3-acetylamino-4-thiazolidonyl)phenothiazines were synthetized and characterized by their sharp melting points and elemental analyses. All compounds inhibited nicotinamide adenine dinucleotide (NAD)-dependent oxidation of pyruvate and alpha-ketoglutarate selectively, whereas NAD-independent oxidation of succinate remained unaltered. All phenothiazine derivatives exhibited anticonvulsant activity, which was reflected by the 20-60% protection observed against pentylenetetrazol-induced convulsions in mice. The ability of substituted thiosemicarbazidophenothiazines to inhibit cellular respiratory activity was reduced considerably by cyclization to the corresponding substituted thiazolidinophenothiazines. On the other hand, cyclization generally resulted in increased anticonvulsant activity. Thus, the anticonvulsant activity possessed by these substituted phenothiazines bore no relationship with their ability to inhibit selectively the NAD-dependent oxidations. Selective inhibition of NAD-dependent oxidation of pyruvate and alpha-ketoglutarate in isolated rat brain mitochondria by some 10-(1-acetyl-4-arylthiosemicarbazido) phenothiazines was concentration dependent and competitive in nature.     

Synthesis of N,N'-bis(3-substituted benzylideneaminopropyl)-piperazines and their anti-inflammatory, antiproteolytic, and anticonvulsant properties.

Some N,N'-bis(3-substituted benzylideneaminopropyl) piperazines were synthesized and characterized by their sharp melting points and elemental analyses. These substituted piperazines possessed anti-inflammatory activity, and the protection afforded by these compounds against carrageenan-induced edema ranged from 23 to 67%. The antiproteolytic activity of these piperazines was reflected by their ability to inhibit in vitro hydrolysis of bovine serum albumin and casein by trypsin. The inhibition of trypsin-induced hydrolysis was concentration dependent and competitive in nature.     

Synthesis and anti-inflammatory evaluation of some pyrazolo[3,4-b]pyridines

Novel series of pyrazolo[3,4-b]pyridines with basic skeleton different from the known COX inhibitors were synthesized from 5-amino-1-[4-(aminosulfonyl)phenyl]-3-phenyl-1H-pyrazole, which in turn was prepared by the condensation of (4-sulfamoylphenyl)hydrazine with α-cyanoacetophenone. All the newly synthesized compounds were tested for their in vivo anti-inflammatory activity by carrageenan-induced rat paw edema assay. Some of the most potent compounds were evaluated in different COX and LOX assays. Some of the new compounds were found to possess moderate anti-inflammatory activity.     

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 of substituted thiobenzoxazoles/benzothiazoles: inhibition of cellular respiratory and monoamine oxidase activities and anticonvulsant property.

Several 2-(substituted alkoxy/hydrazinocarbonyl acetanilidothio)benzoxazoles/benzothiazoles were synthesized and characterized by their sharp melting points, elemental analyses, and IR spectra. All thiobenzoxazoles/benzothiazoles possessed low anticonvulsant activity, which was reflected by the 10-40% protection afforded by these compounds against pentylenetetrazol-induced convulsions. All thiobenzoxazoles/benzothiazoles inhibited selectively the nicotinamide adenine dinucleotide (NAD)-dependent oxidation of pyruvate, DL-isocitrate, and alpha-ketoglutarate by rat brain homogenates. NAD-independent oxidation of succinate remained unaltered. All 2-(substituted hydrazinocarbonyl acetanilidothio)benzoxazoles/benzothiazoles inhibited monoamine oxidase activity of rat brain homogenates. Greater monoamine oxidase inhibition was observed with thiobenzothiazoles than with the corresponding thiobenzoxazoles/benzothiazoles was found to be unrelated with their ability to inhibit cellular respiratory and monoamine oxidase activities of rat brain homogenates.