Synthesis and analgesic and anti-inflammatory activity of 6-phenyl/(4-methylphenyl)-3(2H)-pyridazinon-2-propionamide derivatives.

For reducing gastrointestinal toxicity associated with non-steroidal anti-inflammatory drugs (NSAIDs) a variety of 6-phenyl/(4-methylphenyl)-3(2H)-pyridazinon-2-propionamide were synthesized. The structures of these new pyridazinone derivatives were confirmed by their IR, 1H-NMR spectra and elementary analysis. All the new compounds were tested in vivo for their analgesic and anti-inflammatory activities. The analgesic activity of the test compounds was determined by phenylbenzoquinone-induced writhing assay and the anti-inflammatory activity was evaluated by the carrageenan-induced rat paw edema model. 6-Phenyl-3(2H)-pyridazinon-2-yl-[4-(4-fluorophenyl)piperazinyl] propanamide IVa-3 was the most active one among the synthesized compounds. Also this compound exhibited most potent anti-inflammatory activity. Acetylsalicylic acid and indometacin were used as reference drugs. Adverse effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with the reference NSAIDs.

Design and synthesis of some (S)-2-(6-methoxynaphthalen-2-yl)-N-substituted ethyl propanamide derivatives as potent non-ulcerogenic anti-inflammatory and analgesic agents.

The carboxylic acid group of the anti-inflammatory drug, (S)-2-(6-methoxynaphthalen-2-yl) propanoic acid, naproxen (CAS 22204-53-1) was reacted with the substituted ethylamine derivatives to form (S)-2-(6-methoxynaphthalen-2-yl)-N-substituted ethyl propanamides by using N,N'-dicyclohexyl carbodiimide (DCC) and 4-(dimethylamino)pyridine (DMAP). Anti-inflammatory and analgesic activities of the compounds were assessed in vivo by carrageenan-induced hind paw edema and p-benzoquinone induced abdominal contraction tests in mice, respectively. In addition, the ulcerogenic properties of the new compounds were evaluated, and compared to that of naproxen. Among the newly synthesized compounds, compound 2f showed the highest analgesic and antiinflammatory activity at 100 mg/kg oral dose, without inducing any gastric lesion. Although this compound induced less gastric lesions than naproxen, it was found to have less anti-inflammatory and analgesic activity when compared to indometacin (CAS 53-86-1). These new compounds therefore deserve further attention to develop new lead drugs.

Synthesis and analgesic and anti-inflammatory activities 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(p-substituted/nonsubstituted benzal)hydrazone derivatives.

In this study new 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(p-substituted benzal)hydrazone V derivatives were synthesized as analgesic and anti-inflammatory agents. The structures of compounds were elucidated by spectral and elemental analysis. Compounds Va, Vb and Vc were exhibited more potent analgesic activity than ASA. Also these derivatives demonstrated anti-inflammatory activity as well as standard compound indomethacin. 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 (NSAIDs). On the basis of available data, the structure-activity relationship of V derivatives was also discussed.

Anti-inflammatory and antinociceptive potential of major phenolics from Verbascum salviifolium Boiss.

The potential effects of flavonoids, phenylethanoid and neolignan glycosides from the aerial parts of Verbascum salviifolium Boiss. were studied in the p-benzoquinone-induced writhing reflex, for the assessment of the antinociceptive activity, and in carrageenan- and PGE1-induced hind paw edema and 12-O-tetradecanoyl-13-acetate (TPA)-induced ear edema models in mice, for the assessment of the anti-inflammatory activity. Through bioassay-guided fractionation and isolation procedures ten compounds from the aqueous extract of the plant, luteolin 7-O-glucoside (1), luteolin 3'-O-glucoside (2), apigenin 7-O-glucoside (3), chrysoeriol 7-O-glucoside (4), beta-hydroxyacteoside (5), martynoside (6), forsythoside B (7), angoroside A (8), dehydrodiconiferyl alcohol-9'-O-beta-D-glucopyranoside (9) and dehydrodiconiferyl alcohol-9-O-beta-D-glucopyranoside (10), were isolated and their structures were elucidated by spectral techniques. Results have shown that 1, 2, 3 and 5 significantly inhibited carrageenan-induced paw edema at a 200 mg/kg dose, while 1, 2 and 5 also displayed anti-inflammatory activity against the PGE1-induced hind paw edema model. However, all the compounds showed no effect in the TPA-induced ear edema model. The compounds 1 and 2 also exhibited significant antinociceptive activity.

In vivo anti-inflammatory and antinociceptive activity evaluation of phenolic compounds from Sideritis stricta.

An acetone extract obtained from aerial parts of S. stricta Boiss. & Heldr. apud Bentham, its fractions and phenolic compounds were investigated for their in vivo anti-inflammatory and antinociceptive activities. For the anti-inflammatory activity and for the antinociceptive activity assessment, carrageenan-induced hind paw edema and p-benzoquinone-induced abdominal constriction tests were used, respectively. The acetone extract of the plant and its phenolic fraction exhibited potent inhibitory activity against both bioassay models in mice. From the active phenolic fraction a well-known phenylethanoid glycoside, verbascoside (acteoside) (1), and two flavonoid glycosides, isoscutellarein 7-O-[6"'-O-acetyl-beta-D-allopyranosyl-(1-->2)]-beta-D-glucopyranoside (2) and isoscutellarein 7-O-[6"'-O-acetyl-beta-D-allopyranosyl-(1-->2)]-6"-O-acetyl-beta-D-glucopyranoside (3), were isolated. During phytochemical studies we also isolated a methoxyflavone, xanthomicrol (4), from the non-polar fraction. The structures of the isolated compounds were established by spectroscopic evidence (UV, IR, 1D- and 2D-NMR, MS). Although antinociceptive and anti-inflammatory activities of the phenolic components were found not significant in the statistical analysis, compounds 1 to 3 showed a notable activity without inducing any apparent acute toxicity as well as gastric damage. Furthermore, a mixture of flavonoid glycosides (2 + 3) exhibited a significant inhibitory effect in both models at a higher dose.

Estimation of antinociceptive and anti-inflammatory activity on Geranium pratense subsp. finitimum and its phenolic compounds.

To obtain experimental evidence on the therapeutic efficacy of Geranium species and its phenolic compounds for inflammatory diseases, we examined the effects of the aqueous extract of the aerial parts of Geranium pratense subsp. finitimum (Woronow) Knuth, its fractions and isolated compounds, the mixture of quercetin 3-O-alpha-arabinopyranoside, kaempferol 3-O-beta-galactopyranoside (1), the mixture of quercetin 3-O-beta-glucopyranoside, quercetin 3-O-beta-galactopyranoside (2), kaempferol 3-O-beta-glucopyranoside (3), (-)-6-chloroepicatechin (4), the mixture of quercetin 3-O-(2''-O-galloyl)-beta-glucopyranoside, quercetin 3-O-(2''-O-galloyl)-beta-galactopyranoside (5) and myricetin 3-O-(2''-O-galloyl)-beta-glucopyranoside (6), on carrageenan-, PGE(2)- and TPA-induced inflammation in mice and p-benzoquinone-induced writhing reflex to assess anti-inflammatory and antinociceptive activities. The effective dose of materials for the inhibition of carragenan-induced hind paw edema assay was determined to be 100 mg/kg, which was also used in the assays with the extract, its fractions and isolated compounds in all other experiments. The aqueous extract, 1, 2 (100 mg/kg), as well as indomethacin (10 mg/kg) inhibited significantly the formation of the carrageenan-induced hind paw edema. There was also a significant reduction in PGE(2)-induced hind paw edema and TPA-induced ear edema models with 5, in addition to the aqueous extract and the other active components 1 and 2. In the antinociceptive assay, the aqueous extract and its fractions, as well as 1, 2, and 5 diminished significantly the number of writhings. Based on the results obtained it is suggested that the aqueous extract of Geranium pratense subsp. finitimum and its phenolic compounds display anti-inflammatory activity, supporting the folkloric use.

Assessment of anti-inflammatory and antinociceptive activities of Daphne pontica L. (Thymelaeaceae).

The n-hexane, diethylether, ethyl acetate and methanol extracts from roots, leaves, stems and flowers with young leaves of Daphne pontica L. (Thymelaeaceae) were investigated for their in vivo anti-inflammatory and antinociceptive activities. For the anti-inflammatory activity assessment, carrageenan-induced hind paw edema, PGE(2)-induced hind paw edema and 12-O-tetradecanoyl-13-acetate (TPA)-induced mouse ear edema models and for the antinociceptive activity, p-benzoquinone-induced abdominal constriction test were used. Only ethyl acetate extracts of the roots showed significant anti-inflammatory activity on carrageenan-induced (22.7-32.0% inhibition) and PGE(2)-induced hind paw edema (3.2-27.3% inhibition) as well as 12-O-tetradecanoyl-13-acetate (TPA)-induced mouse ear edema (47.8-43.3% inhibition) models at 50 mg/kg dose without inducing any apparent gastric lesion or acute toxicity, whereas the other extracts were shown to be ineffective. In addition to roots, ethyl acetate extracts of the stems exhibited 19.5-29.9%; 5.3-23.9%; 36.6-28.1% inhibition on carrageenan-induced and PGE(2)-induced hind paw edema as well as 12-O-tetradecanoyl-13-acetate (TPA)-induced mouse ear edema models, respectively. On the other hand, none of the extracts showed any significant antinociceptive activity.

A new therapeutic approach in Alzheimer disease: some novel pyrazole derivatives as dual MAO-B inhibitors and antiinflammatory analgesics.

The increasing life expectancy in our population makes Alzheimer's disease (AD) a growing public health problem. There is a great need to find a way to prevent and delay the disease. It was shown that monoamine oxidase-B (MAO-B) inhibitors and antiinflammatory agents might be effective in treating AD. Therefore, a novel series of 1-thiocarbamoyl-3-substituted phenyl-5-(2-pyrrolyl)-4,5-dihydro-(1H)-pyrazole derivatives as promising MAO-B inhibitors was synthesized and investigated for the ability to inhibit selectively the activity of the A and B isoforms of monoamine oxidase (MAO). Most of the synthesized compounds showed high activity against both the MAO-A (compounds 3e-3h) and the MAO-B (compounds 3i-3l) isoforms. All the synthesized compounds were also tested for their in vivo antiinflammatory activity by two different bioassays namely, carrageenan-induced oedema and acetic acid-induced increase in capillary permeability in mice. In addition, analgesic and ulcerogenic activities were determined. The combined antiinflammatory data from in vivo animal models showed that compound 3k exhibited anti-inflammatory activity comparable to that of indomethacin with no ulcerogenic effects. Since compound 3k exhibits both antiinflammatory-analgesic activity and MAO-B inhibition, it needs further detailed studies.

Flavonoids with anti-inflammatory and antinociceptive activity from Cistus laurifolius L. leaves through bioassay-guided procedures.

Extracts obtained from the leaves and branches of various Cistus species have been used worldwide as folk remedy for the treatment of various inflammatory ailments including rheumatism and renal inflammations. Effects of the extracts and fractions from the leaves with non-woody branches of Cistus laurifolius L. (Cistaceae) were studied using two in vivo models of inflammation in mice. Model one was based on observed potent inhibitory activity against carrageenan-induced hind paw oedema and the second model used was acetic acid-induced, increased vascular permeability model. Through bioassay-guided fractionation and isolation procedures three flavonoids; 3-O-methylquercetin (1), 3,7-O-dimethylquercetin (2) and 3,7-O-dimethylkaempferol (3) were isolated as the main active ingredients from the ethanol extract. Later on, these flavonoids were shown to possess potent antinociceptive activity, which was assessed through inhibition of p-benzoquinone-induced writhing reflex. Results of the present study have clearly supported the utilization of Cistus laurifolius in Turkish traditional medicine. Subsequently, three flavonoids were shown to have strong antinociceptive and anti-inflammatory activities, per os without inducing any apparent acute toxicity as well as gastric damage.

Design and synthesis of some new thiazolo [3,2-b]-1,2,4-triazole-5(6H)-ones substituted with flurbiprofen as anti-inflammatory and analgesic agents.

In the course of our ongoing studies, a series of thiazolo[3,2-b]-1,2,4-triazole-5(6H)-ones substituted with flurbiprofen (CAS 5104-49-4) has been prepared. The compounds were synthesized by the cyclization of the 3-[(2-fluoro-4-biphenyl)ethyl]-5-mercapto-1,2,4-triazole (3) with chloroacetic acid and relevant benzaldehydes in the presence of acetic acid, acetic anhydride and anhydrous sodium acetate in one step. The product of this one-pot synthesis that precipitated on cooling of the reaction mixture was identified undoubtedly by X-ray crystallographic analysis as thiazolo[3,2-b]-1,2,4-triazole. In-vivo anti-inflammatory and analgesic activities of the compounds were assessed by carrageenan-induced hind paw edema and p-benzoquinone-induced abdominal constriction tests in mice, respectively. In addition, the ulcerogenic risks were evaluated. It is worthy of saying that the compounds which maintained analgesic/antiinflammatory activity of the starting compound were found to be safer with regard to gastric lesion risks at 100 mg/kg oral dose when compared with flurbiprofen. Among the synthesized compounds 3d showed the highest analgesic and antiinflammatory activity without inducing any gastric lesion and deserves further attention in order to develop new lead drug candidates.

Phenolic compounds of Sideritis ozturkii and their in vivo anti-inflammatory and antinociceptive activities.

Acetone extract from aerial parts of Sideritis ozturkii Aytaç & Aksoy and its fractions were investigated for its in vivo anti-inflammatory and antinociceptive activities. For the anti-inflammatory activity assessment, carrageenan-induced hind paw edema and for the antinociceptive activity, p-benzoquinone-induced abdominal constriction tests were used. Acetone extract of the plant and its phenolic fraction were found to possess significant inhibitory activity on these in vivo models in mice. Ozturkoside A (chrysoeriol 7-O-[2'''-O-caffeoyl-6'''-O-acetyl-beta-d-glucopyranosyl-(1-->2)-beta-d-glucopyranoside]); ozturkoside B (chrysoeriol 7-O-[2'''-O-caffeoyl-beta-d-glucopyranosyl-(1-->2)-beta-d-glucopyranoside]); and ozturkoside C (chrysoeriol 7-O-[2'''-O-p-coumaroyl-6'''-O-acetyl-beta-d-glucopyranosyl-(1-->2)-beta-d-glucopyranoside]) were isolated from the active phenolic fraction. The structures of isolated compounds were elucidated by spectroscopic techniques (UV, IR, 1D- and 2D-NMR, MS). Ozturkoside C showed notable antinociceptive and anti-inflammatory activities without inducing any apparent acute toxicity or gastric damage. Although the activity of ozturkosides A and B were found insignificant in statistical analysis, some inhibitory effect was observed. Accordingly, it is suggested that these components in phenolic fraction might possibly share the antinociceptive and anti-inflammatory activities together.

Effect of brining on biological activity of leaves of Vitis vinifera L. (Cv. Sultani Cekirdeksiz) from Turkey.

Leaves of Vitis vinifera (Fam. Vitaceae) cv. 'Sultani Cekirdeksiz' cultivated in Manisa-Alasehir in western Turkey, were processed with or without brine. Fresh, brined, and nonbrined leaves (after being subjected to 3 months of fermentation) were sampled and extracted with distilled water under reflux. Antioxidant, anti-inflammatory, and anti-nociceptive activities of the water extracts were investigated using in vitro and in vivo methods. Free radical scavenging activity (1,1-diphenyl-2-picrylhydrazyl, DPPH* assay), iron(III) reductive activity (reducing power activity assay), capacity of inhibition of linoleic acid peroxidation (ferric thiocyanate and thiobarbituric acid method), anti-nociceptive activity (p-benzoquinone-induced abdominal constriction test), and anti-inflammatory activity (carrageenan-induced hind paw edema model) were used to determine biological activities of the extracts. In addition, the contents of total phenolics, flavonoids, and flavonols in the extracts were determined by spectrophotometrical methods. Results were compared with those of ascorbic acid, butylated hydroxytoluene, and gallic acid as reference antioxidants. The extracts of fresh, brined, and nonbrined leaves showed almost the same activity in all antioxidant assays. These extracts inhibited the oxidation of linoleic acid to the same extent as BHT. Compositions of the extracts were analyzed by a reverse phase HPLC-PDA method. The occurrence of hydroxycinnamic acids (e.g., caffeic acid) and flavonoids (e.g., quercetin) was verified in the extracts. The content of total flavonoids as well as quercetin was increased by fermentation.

In vivo anti-inflammatory and antinociceptive activity of the crude extract and fractions from Rosa canina L. fruits.

The aqueous and ethanol extracts of Rosa canina L. (Rosaceae) fruits and the fractions prepared from the latter were investigated for their anti-inflammatory and antinociceptive activities in several in vivo experimental models. The ethanolic extract was shown to possess significant inhibitory activity against inflammatory models (i.e., carrageenan-induced and PGE(1)-induced hind paw edema models, as well as on acetic acid-induced increase in a capillary permeability model) and on a pain model based on the inhibition of p-benzoquinone-induced writhing in mice. Hexane, chloroform, ethylacetate, n-butanol and the remaining water fractions were obtained through bioassay-guided fractionation. Ethylacetate and n-butanol fractions displayed potent anti-inflammatory and antinociceptive activities at a dose of 919 mg/kg without inducing acute toxicity. Further attempts to isolate and define the active constituent(s) were inconclusive, possibly due to the synergistic interaction of components in the extract.

Analgesic and antiinflammatory activities of some new Mannich bases of 5-nitro-2-benzoxazolinones.

In this study, the synthesis of a novel series Mannich bases of 5-nitro-3-substituted piperazino-methyl-2-benzoxazolinones are described. The structures attributed to compounds 3a-3k were elucidated using IR, 1H-NMR spectroscopic techniques besides elemental analysis. The compounds were examined for their in vivo antiinflammatory and analgesic activities in two different bioassays, namely, carrageenan-induced hind paw edema and p-benzoquinone-induced abdominal constriction tests in mice, respectively. In addition, the ulcerogenic effects of the compounds were determined. Among the tested derivatives most promising results were obtained for the compounds bearing electron-withdrawing substituents (F, Cl, COCH3) in the ortho/para position of the phenyl nucleus on the piperazine ring at 3 position of benzoxazolinone moiety (3a, 3b, 3c, 3d, 3h). The analgesic activities of all compounds are higher than their antiinflammatory activities. Antiinflammatory inhibitory ratios for all compounds were above 30% for the last two measurements. Because of this compounds 3a, 3b, 3c, 3d deserve attention and may be considered for further evaluation.

Appraisal of anti-inflammatory potential of the clubmoss, Lycopodium clavatum L.

Studies on four extracts prepared with petroleum ether, chloroform, ethyl acetate and methanol as well as the alkaloid fraction from the aerial parts of Lycopodium clavatum L. of Turkish origin using acetic acid-induced increase in capillary permeability assessment in mice revealed that only the chloroform extract and the alkaloid fraction displayed marked anti-inflammatory effect at a dose of 500mg/kg having percentage of inhibition 24.3 and 32.1, respectively, as compared to indomethacin, which exhibited 44.6% of inhibition at 10mg/kg dose. Bioassay-guided fractionation of the alkaloid fraction of Lycopodium clavatum revealed that the alkaloidal-type of compounds might possibly be responsible for the anti-inflammatory activity of the extract, which supports the folk medicinal utilization of the plant. Gas chromatographic-mass spectrophotometric analysis of the active alkaloid fraction revealed that lycopodine (84.5%) is the major component.

Clematis vitalba L. aerial part exhibits potent anti-inflammatory, antinociceptive and antipyretic effects.

Extracts obtained from the dried aerial parts of Clematis species are used as folk remedy worldwide for the treatment of various inflammatory ailments such as rheumatism and to reduce fever. In order to test the effectiveness of extracts, fractions and subfractions from dried Clematis vitalba L. (Ranunculaceae) aerial parts were studied on mice. Extracts are shown to have a potent effect on carrageenan-induced hind paw edema and acetic acid-induced increased vascular permeability models. Through bioassay-guided fractionation procedures a new C-glycosylflavon, 4'-O-coumaroyl-isovitexine (vitalboside) was isolated as the main active ingredient of the aerial parts. Vitalboside showed a potent and dose-dependent (in 75 and 150 mg/kg does, per os) in vivo anti-inflammatory activity against acute (carrageenan-, serotonin- and PGE(2)-induced hind paw edema model, castor oil-induced diarrhea), subacute (subcutaneous air-pouch) and chronic (Freund's complete adjuvant-induced arthritis) models of inflammation. The same compound was also isolated as the main antinociceptive principle which was assessed by using the models based on the inhibition of p-benzoquinone-induced writhings, as well as antipyretic activity against Freund's complete adjuvant-induced increased body temperature. Acute and subchronic toxicity studies were also performed.

Bioassay-guided isolation of anti-inflammatory and antinociceptive glycoterpenoids from the flowers of Verbascum lasianthum Boiss. ex Bentham.

Infusions of Verbascumlasianthum flowers have been used for hemorrhoids in Turkish folk medicine. In order to evaluate the scientific basis for this practice, in vivo anti-inflammatory and antinociceptive activities of Verbascum lasianthum Boiss. ex Bentham flowers were investigated. A methanolic extract of the flowers was shown to possess significant inhibitory activity in the carrageenan-induced hind paw edema model and in p-benzoquinone-induced writhings in mice. Through bioassay-guided fractionation and isolation procedures eight compounds, 6-O-(4'''-O-trans-p-coumaroyl)-alpha-L-rhamnopyranosylaucubin (1), 6-O-(4'''-O-trans-p-methoxycinnamoyl)-alpha-L-rhamnopyranosylaucubin (2), sinuatol (3), aucubin (4), geniposidic acid (5), catalpol (6), ajugol (7) and ilwensisaponin A (8) were isolated and their structures were elucidated by spectral techniques. An iridoid glucoside, aucubin (4) and a triterpenoid saponin, ilwensisaponin A (8) were found to possess significant antinociceptive and anti-inflammatory activities, per os without inducing any apparent acute toxicity or gastric damage. Results of the present study support the continued and expanded utilization of plants employed in Turkish folk medicine.

Preparation of 5-aryl-3-alkylthio-l,2,4-triazoles and corresponding sulfones with antiinflammatory-analgesic activity.

In this study, a series of 5-aryl-3-alkylthio-1,2,4-triazoles and corresponding sulfones were prepared with the objective of developing better analgesic-antiinflammatory compounds with minimum ulcerogenic risk. The structures of the compounds were elucidated by spectral and elemental analysis. The compounds were assayed per os in mice for their antiinflammatory and analgesic activity as well as the ulcerogenic risk and acute toxicity. Several of these compounds showed significant activity. Alkylsulfone derivatives were found to be much more potent analgesic-antiinflammatory agents than the corresponding alkylthio analogs. Compounds 9 and 11 were the most active of the series in both analgesic and antiinflammatory activity tests. In contrast to reference compound acetyl salicylic acid, these compounds did not induce gastric lesions in the stomach of experimental animals at the doses that exhibited analgesic/antiinflammatory activity.

Antioxidant, anti-inflammatory, anti-nociceptive activities and composition of Lythrum salicaria L. extracts.

Lythrum salicaria (purple loosestrife) known as "Tibbi hevhulma" in Turkish is used for its several beneficial health effects against as diarrhea, chronic intestinal catarrh, hemorrhoid and eczema in the form of a decoction or a fluid extract and to treat varicose veins, bleeding of the gums, hemorrhoid and eczema, externally. Dried herbal parts of Lythrum salicaria L. (Lythraceae) were sequentially extracted with different solvents such as petroleum ether, ethyl acetate, methanol and 50% aqueous methanol. Water extract of Lythrum salicaria was also prepared under reflux. Antioxidant, anti-inflammatory and anti-nociceptive activities of all the extracts were investigated using in vitro and in vivo methods, respectively. Free radical scavenging activity (1,1-diphenyl-2-picrylhydrazyl, DPPH* assay), iron(III) reductive activity, capacity of the inhibition of linoleic acid peroxidation and MDA formation, anti-nociceptive activity (p-benzoquinone-induced abdominal constriction test) and anti-inflammatory activity (carrageenan-induced hind paw edema model) were used for all the extracts. In addition, the content of total phenolics, flavonoids and flavonols in all the extracts were determined with spectrophotometric methods. Results were compared with reference antioxidants via ascorbic acid, butylated hydroxytoluene, and gallic acid. Qualitative and quantitative compositions of all the extracts were analysed using a HPLC-PDA system. Polar fractions were found to be rich in flavonoids such as isovitexin and isoorientin.

Synthesis and analgesic and anti-inflammatory activity of ethyl (6-substituted-3 (2H)-pyridazinone-2-yl)acetate derivatives.

A number of 6-substituted-3(2H)-pyridazinones and the corresponding methyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate derivatives carrying the arylpiperazinyl structure present in potent antinociceptive agents reported in the literature were synthesized. As part of a programme a series of diverse arylpiperazine derivatives of ethyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate 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. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with reference non-steroidal anti-inflammatory drugs (NSAIDs). On the basis of available data, the structure-activity relationship in the series of ethyl (6-substituted-3(2H)-pyridazinone-2-yl)acetate derivatives was also discussed. When compared to parent 6-substituted-3(2H)-pyridazinones, the new ester derivatives, for example ethyl (6-4-[(2-fluoro)phenyl]piperazine-3(2H)-pyridazinone-2-yl)acetate exhibited better analgesic and anti-inflammatory activity and a lower ulcerogenic effect.