Synthesis,analgesic and anti-inflammatory activities of some novel 2,3-disubstituted quinazolin-4(3H)-ones

A series of novel 2-benzylamino-3-substituted quinazolin-4(3H)-ones have been synthesized by treating 3-amino-2-benzylamino quinazolin-4(3H)-one, with different aldehydes and ketones. The starting material 3-amino-2-benzylamino quinazolin-4(3H)-one was synthesized by nucleophilic substitution of thiomethyl group of 3-amino-2-methylthio quinazolin-4(3H)-one by benzylamine. The title compounds were investigated for analgesic and anti-inflammatory activities. All the test compounds exhibited significant analgesic activity, whereas the compound III is equipotent with diclofenac sodium. The compounds I, II and III showed more potent anti-inflammatory activity than diclofenac sodium.     

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.     

Synthesis of some novel azo derivatives of 3,5-dimethyl-1-(2-hydroxyethyl)pyrazole as potent analgesic agents

A series of 1-(2-hydroxyethyl)-3,5-dimethylpyrazolylazo derivatives, incorporating thiosemicarbazide 2a-c, 1,3,4-thiadiazole 3a-c, and 1,2,4-triazole-3-thione 4a-c were synthesized. The structure of these novel synthesized compounds 2a-c, 3a-c, and 4a-c was confirmed by spectral analysis. All these compounds were screened for their analgesic activity. Hot-plate and tail-immersion tests were used for the determination of the analgesic activity. Morphine, an analgesic through both spinal and supraspinal pathways, was used as a standard test drug. All compounds were administered at a dose of 100 mg/kg i.p. Among the compounds, 2-(butylamino)-5-[((1-(2-hydroxyethyl)-3,5-dimethylpyrazole-4-yl)azo)phenyl]-1,3,4-thiadiazole 3a and 4-[((1-(2-hydroxyethyl)-3,5-dimethylpyrazole-4-yl)azo)phenyl]-4-(2-phenethyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione 4c showed analgesic effects in both tests. Especially 4c exerted strong analgesia starting at 30 min after injection.     

Investigation of antioxidant and anti-nociceptive potential of isoxazolone,pyrazolone derivatives,and their molecular docking studies

A series of new isoxazolone ( 3a – d ) and pyrazolone ( 4a – d ) derivatives were synthesized and assessed for their antioxidant and analgesic activity. Among synthesized compounds, 3b and 4b having nitro (NO₂) group show high analgesic activity at a dose of 6 mg/kg. Analgesic activity was further proceeded to explore the contribution of opioidergic mechanisms in the mediation of analgesic effects. Animals were administered with naloxone, a nonselective opioid inverse agonist, at the dose of 0.5 mg/kg. The results obtained suggested that the analgesic effects of the synthesized compounds were not reversed by naloxone, specifying that the compounds 3b and 4b do not follow the opioidergic pathway in order to relieve pain in animal models. Further, the binding interactions of compounds 3b and 4b were analyzed by docking them against nonopioid receptors COX-1 (3N8X) and COX-2 (3LN1). The results demonstrate the analgesic potential of isoxazolone and pyrazolone derivatives, especially compounds 3b and 4b can be considered promising lead molecules for further investigation and development into potent analgesic drugs. In addition, the antioxidant potential of compounds was also found to be related to better analgesic activity, thus providing an insight into the role of oxidative stress in the mediation of analgesia.     

Facile synthesis of fused pyrazolo[1,5-a]pyrimidinepyrazolo [1,5-a]triazines and N-sulphonamidopyrazoles as antiinflammatory

Interaction of hydrazine hydrate with methyl (2-E)-2-cyano-3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]-3-(methylsulphanyl)-2-propenoate 2 which was obtained by the reaction of methyl-2-cyano-3,3-bis(methylsulphanyl) acrylate 1 with 4-amino-1-phenyl-2,3-dimethyl pyrazoline-5-one afforded methyl-5-amino-3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]-1H-pyrazole-4-carboxylate 3a. The pyrazolin derivative 3a is a good precursor for the synthesis of pyrazolo[1,5-a]pyrimidines which is based on the interaction of 3a with alpha,beta-unsaturated nitrile derivatives. The biological effects of some of the newly synthesized compounds were also investigated as antiinflammatory, analgesic and antipyretic drugs. Compounds 2b, 4a, 3a, 3b, 2a and 4b were found to have significant antiinflammatory activity in descending order in comparison to control groups phenylbutazone. Compounds 3a, 2a, 4b, 4a, 2b and 3b have analgesic activity in decreasing order. Compound 3a was the most potent and had 82.6% potency of Novalgin. Compounds 2b, 2a, 3b, 4b, 3a and 4a were found to have significant antipyretic activity in descending order. Compounds 2a, 4b induced no ulcerogenic activity, while compounds 3b, 2b, 4a and 3a showed only slight ulcerogenic activity.     

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, analgesic, anti-inflammatory and antibacterial activities of some novel 2-butyl-3-substituted quinazolin-4-(3H)-ones

A variety of novel 2-butyl-3-substituted quinazolin-4-(3H)-ones have been synthesized by reacting (2-butyl-4-oxo-3H-quinazolin-3-yl)dithiocarbamic acid methyl ester with a variety of amines; the starting material dithiocarbamate was synthesized from anthranilic acid. The title compounds were investigated for analgesic, anti-inflammatory and antibacterial activities. While the test compounds exhibited significant activity, compounds A1, A2, A3 and A4 showed more potent analgesic activity and compound A4 showed more potent anti-inflammatory activity than the reference diclofenac sodium.     

Design and SAR of novel potassium channel openers targeted for urge urinary incontinence. 2. Selective and potent benzylamino cyclobutenediones

A novel series of benzylamine, potassium channel openers (KCOs) is presented as part of our program toward designing new, bladder-selective compounds for the treatment of urge urinary incontinence (UUI). We have found that the in vitro potency of (R)-4-[3,4-dioxo-2-(1,2, 2-trimethyl-propylamino)-cyclobut-1-enylamino]-3-ethyl-benzo nitrile 1 in the relaxation of precontracted rat detrusor strips can also be obtained with cyanobenzylamine derivative 4 (IC(50) = 0.29 microM) (Figure 3). Addition of a 2-Cl substituted benzylamine moiety and changing the alkylamino substituent of 4 to a t-Bu amine gives 31 (IC(50) = 0.14 microM)-a compound with similar in vitro potency as 4 as well as relaxant activity on bladder smooth muscle in vivo when administered orally (31, ED(50) = 3 mg/kg) in a rodent model of bladder instability. Further modifications, particularly the replacement of the t-Bu amino substituent with a tert-amylamine, gave a similarly active compound 60 (IC(50) = 0.10 microM) which shows excellent in vivo efficacy (ED(50) = 0.6 mg/kg). Moreover, 60, 3-(2,4-dichloro-6-methyl-benzylamino)-4-(1, 1-dimethyl-propylamino)-cyclobut-3-ene-1,2-dione (WAY-151616), shows excellent tissue selectivity for bladder K channels over arterial tissue (60, MAP ED(20) = 100 mg/kg; selectivity: MAP ED(20)/bladder ED(50) = 166). Other manipulations of the benzylamino cyclobutenediones, acylation of the benzylamine, conversion of the benzylamine substituent to a benzamide, homologation of the benzylamine to a phenethylamine, and incorporation of a methyl group at the benzyl carbon, all led to substantial loss of in vitro activity, although some in vivo activity was maintained in the acylated analogues. Compound 60 represents an attractive candidate for development in the treatment of UUI.     

Synthesis, analgesic, anti-inflammatory and antibacterial activities of some novel 2-methylthio-3-substituted quinazolin-4-(3H)-ones

A variety of novel 2-methylthio-3-substituted quinazolin-4-(3H)-ones have been synthesized by reacting (2-methylthio-4-oxo-3H-quinazolin-3-yl)dithiocarbamic acid methyl ester with a variety of amines, the starting material dithiocarbamate was synthesized from methylanthranilate. The title compounds were investigated for analgesic, anti-inflammatory and antibacterial activities. While the test compounds exhibited significant activity, the compounds A1, A2, A3 and A4 shown more potent analgesic activity, and the compound A4 shown more potent anti-inflammatory activity than the reference diclofenac sodium.     

Synthesis and pharmacological properties of 9-(N, N-dimethylaminopropyl)-1,2,3,4-tetrahydro-beta-carbolines

Three novel tetrahydro-beta-carbolines: 9-(N, N-dimethyl-aminopropyl)-1,2,3,4-tetrahydro-beta carboline (2a), and its 1-methyl (2b) and 1-ethyl (2c) derivatives, were synthesized and investigated for their central action in mice. The compounds given in subtoxic doses caused sedation and loss of righting reflex. At low doses (approx 0.2 LD50) compounds 2a and 2b initially depressed, and then stimulated the locomotor activity, and at high doses they inhibited pentylenetetrazole convulsions. All three compounds displayed some analgesic action. Compunds 2a and 2b transeintly depressed the body temperature.     

Synthesis and Biological Evaluation of ��-Aroylpropionic acid based 1,3,4-Oxadiazoles

In the present investigation, two new series, 1-(4-benzylphenyl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)-1-propanone and 1-(4-ethylphenyl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)-1-propanone from β-(4-benzylbenzoyl)propionic acid and β-(4-ethylbenzoyl)propionic acid, respectively, were synthesized and tested for antiinflammatory, analgesic, lipid peroxidation, ulcerogenic and antibacterial actions. A fair number of compounds were found to have good antiinflammatory activity in carrageenan-induced rat paw edema test, while a few compounds showed significant antibacterial activity. The newly synthesized compounds showed very low ulcerogenic action.     

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

A variety of novel 3-(2-methylphenyl)-2-substituted amino-quinazolin-4(3H)-ones were synthesized by reacting the amino group of 2-hydrazino-3-(2-methylphenyl)-quinazolin-4(3H)-one with a variety of aldehydes and ketones. The starting material 2-hydrazino-3-(2-methylphenyl)-quinazolin-4(3H)-one was synthesized from 2-methyl aniline. The title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic index activities. Among these, the compound 2-(1-ethylpropylidene)-hydrazino-3-(2-methylphenyl)-quinazolin-4(3H)-one emerged as the most active compound for analgesic activity, while the compound 2-(1-methylbutylidene)-hydrazino-3-(2-methylphenyl)-quinazolin-4(3H)-one showed most potent anti-inflamma-tory activity of the series and was moderately more potent in its anti-inflammatory activity when compared to the reference standard diclofenac sodium (CAS 15307-86-5). Interestingly, the test compounds showed only mild ulcerogenic potential when compared to acetylsalicylic acid (CAS No: 50-78-2).     

Synthesis and pharmacological evaluation of 1-(1-((substituted)methyl)-5-methyl-2-oxoindolin-3-ylidene)-4-(substituted pyridin-2-yl)thiosemicarbazide

Some novel Mannich base isatin derivatives were synthesized by reacting 1-(5-methyl-2-oxoindolin-3-ylidene)-4-(substitutedpyridin-2-yl)thiosemicarbazide with formaldehyde and several secondary amines. Their chemical structure was elucidated by means of spectral (FT-IR, (1)H- and (13)C-NMR and mass) analysis. Investigation of anti-inflammatory activity of synthesized compounds was done by carrageenan induced paw oedema method using diclofenac sodium as standard drug and analgesic activity was done by acetic acid induced writhing method. The synthesized compounds showed significant anti-inflammatory and analgesic activity.     

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.     

Effect of the oral absorption of benzenesulfonanilide-type cyclooxygenase-1 inhibitors on analgesic action and gastric ulcer formation

A benzensulfonanilide-type cyclooxygenase-1 (COX-1)-selective inhibitor, ZXX2-77: 4-amino-4'-chloro-N-methylbenzenesulfonanilide (4a), has been reported as a novel analgesic that does not cause gastric damage. This compound has a weak analgesic effect but has potent in vitro COX-1 inhibitory activity. Since the reason for the weak analgesic effect in vivo was thought to be the low rate of oral absorption, the blood concentration of ZXX2-77 (4a) was measured in rats. It was found that the C(max) value (1.2 microM) of ZXX2-77 (4a) at a dose of 30 mg/kg did not reach the COX-1 IC(50) value (3.2 microM). On the other hand, ZXX2-79 (4b) (SO(2)NH derivative of ZXX2-77 (4a); 4-amino-4'-chlorobenzenesulfonanilide), which shows less potent COX inhibitory activities (COX-1 IC(50) = 12 microM, COX-2 IC(50) = 150 microM) than those of ZXX2-77 (4a) in vitro, was found to be more absorbable (C(max) = 16 microM at a dose of 30 mg/kg in rats) than ZXX2-77 (4a). Furthermore, ZXX2-79 (4b) not only showed a potent analgesic effect in a formalin test but also caused little gastric damage. These findings indicate that demethylated sulfonamide compounds are more easily absorbed than are N-methylated sulfonamide compounds and suggest that COX-1-selective inhibitors will be useful as analgesics that do not cause gastric damage.     

A novel indole alkaloid from deep-sea sediment metagenomic clone-derived Escherichia coli fermentation broth

To explore secondary metabolites in deep-sea sediment metagenomic clone-derived Escherichia coli fermentation broth, different kinds of chromatography methods were used in the isolation procedures, while the structures of the isolated compounds were assigned based on the MS analysis and their (1)H and (13)C NMR spectra including 2D NMR techniques such as COSY, HMQC, and HMBC experiments. As a result, a novel compound was isolated and characterized as N-{1-[4-(acetylamino)phenyl]-3-hydroxy-1-(1H-indol-3-yl)propan-2-yl}-2,2-dichloroacetamide (1). In addition, eight known compounds were also obtained. Fatty acid amide hydrolase and monoacylglycerol lipase were used to screen analgesic activity, and the new compound showed analgesic activity to some extent in pharmacological test.     

Synthesis, analgesic, anti-inflammatory, and in vitro antimicrobial activities of some novel quinazolin-4(3H)-one derivatives

With the aim of developing potent analgesic, anti-inflammatory, and antimicrobial agents a series of novel quinazolin-4(3H)-one derivatives were synthesized and characterized by FT-IR, ¹H-NMR, mass spectroscopy and bases of elemental analysis. Tail-flick technique, carrageenan-induced foot paw edema test, and agar streak dilution test were performed for screening analgesic, anti-inflammatory, and in vitro antimicrobial activity, respectively. Moreover, all compounds were examined for its ulcerogenicity. Results revealed that entire series of compounds exhibited mild to good analgesic, anti-inflammatory, and antimicrobial activity with low to moderate ulcer index. The relationship between the functional group variation and the biological activity of the evaluated compounds were discussed. Compound 2-(2-(4-(trifluoromethyl)benzylidene)hydrazinyl)-N-(4-(2-methyl-4-oxoquinazolin-3(4H)-yl) phenyl) acetamide 5e was determined to be the most active compound.     

Synthesis,analgesic, anti-inflammatory and antibacterial activities of some novel 2-phenyl-3-substituted quinazolin-4(3H) ones

A series of novel 2-phenyl-3-substituted quinazolin-4(3H)-ones have been synthesized by treating methyl-N-(2-phenyl quinazolin-3-yl-4(3H)-one) dithiocarbamate with different amines, the starting material dithiocarbamate was synthesized from anthranilic acid. The title compounds were investigated for analgesic, anti-inflammatory and antibacterial activities. All the test compounds exhibited significant activity, the compounds A1, A2 and A3 shown more potent analgesic activity, and the compound A3 shown more potent anti-inflammatory activity than the reference standard diclofenac sodium.     

Cannabilactones: a novel class of CB2 selective agonists with peripheral analgesic activity

The identification of the CB2 cannabinoid receptor has provided a novel target for the development of therapeutically useful cannabinergic molecules. We have synthesized benzo[ c]chromen-6-one analogs possessing high affinity and selectivity for this receptor. These novel compounds are structurally related to cannabinol (6,6,9-trimethyl-3-pentyl-6 H-benzo[ c]chromen-1-ol), a natural constituent of cannabis with modest CB2 selectivity. Key pharmacophoric features of the new selective agonists include a 3-(1',1'-dimethylheptyl) side chain and a 6-oxo group on the cannabinoid tricyclic structure that characterizes this class of compounds as "cannabilactones." Our results suggest that the six-membered lactone pharmacophore is critical for CB2 receptor selectivity. Optimal receptor subtype selectivity of 490-fold and subnanomolar affinity for the CB2 receptor is exhibited by a 9-hydroxyl analog 5 (AM1714), while the 9-methoxy analog 4b (AM1710) had a 54-fold CB2 selectivity. X-ray crystallography and molecular modeling show the cannabilactones to have a planar ring conformation. In vitro testing revealed that the novel compounds are CB2 agonists, while in vivo testing of cannabilactones 4b and 5 found them to possess potent peripheral analgesic activity.