Chemical constituents of Desmodium sequax

1081-108

SCREENING OF SYNTHETIC NEW HETEROCYCLIC DERIVATIVES OF 3- FORMYL-4-HYDROXYCOUMARIN FOR ANTI-INFLAMMATORY ACTIVITY IN ALBINO RATS

Coumarins have multiple biological activities; various coumarin-related derivatives arerecognized as inhibitors of the lipoxygenase and cycloxygenase pathways of arachidonatemetabolism. Several natural or synthetic coumarins with various hydroxyl and other substituteswere found to inhibit lipid peroxidation and to scavenge hydroxyl radical and superoxide anionand to influence processes involving free radical mediated injury. The heterocyclic derivatives of3-formyl-4-hydoxycoumarin were found to present significant anti-inflammatory effect, thecompounds inhibited formalin induced hind paw edema and they also significantly suppressedthe formation of granuloma tissue in cotton pellet induced chronic model of inflammation. Theresult showed that the anti-inflammatory (both acute & chronic) effect of the test compound Ib iscomparable to that of standard Antiinflammatory drug Diclofenac Sodium

Novel pyrazolopyrones from enol lactones

1609-1613The one pot and facile condensation reaction of 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde 1, 5-azido-3-methyl-1-phenylpyrazole-4-carboxaldehyde 2 with triacetic acid lactone 3 and 4-hydroxycoumarin 4 affords isomeric pyrazolopyrones viz. 4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-2-one-3-yl)-3,7-dime­th­yl-1-phenylpyrazolo­[3,4:2,3]-4H-pyrano [3,2-b]pyran-5-one 6, 4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-2-one-3-yl)-3,7-dimethyl -1-phenylpyrazolo[3,4:2,3]-4H-pyrano[3,2-c]pyran-5-one 7 and 4-(4-hydroxy-2-oxo-2H-1-benzopyran-2-one-3-yl)-3-methyl-1-phenyl­pyrazolo[3,4:2,3]-4H-pyrano[3,2-b]-1-benzopyran-5-one 8, 4-(4-hydroxy-2-oxo-2H-1-benzopyran-2-one-3-yl)-3-methyl-1-phenyl­pyrazolo[3,4:2,3]-4H-pyrano[3,2-c]-1-benzopyran-5-one 9 res­pecti­­vely. The condensation reaction which has led to the forma­tion of isomeric compounds is similar to Simonis conden­sa­tion reaction of oxoesters. The structures of all newly synthesized compounds have been determined by IR, 1H NMR and mass spectral data

New heterocyclic derivatives of 3-formyl-4-hydroxycoumarin

2704-2709Condensation of 4-hydroxy-2-oxo-2H-[1]benzopyran-3-carboxaldehyde 1 with triacetic acid lactone 2, 5, 5-dimethylcyclohexan-1,3-dione 5 and 3-methyl-1-phenyl-5-pyrazolone 7 in refluxing ethanol affords 3-acetoacetyl­pyrano[3,2-c][1]benzopyran-2,5-dione 3, 7-(4-hydroxycoumarin-3-yl)-10,10-dimethyl-8-oxo-8,9, 10,11-tetrahydropyrano [3,2-c] coumarin 6 and methylidine-bis-4,4' -[3-methyl-5-oxo-1-phenylpyrazole] 9. Pyrazoles 4a,b and isoxazole 4c are obtained by treatment of 3 in acetic acid with hydrazine, phenylhydrazine and hydroxylamine. Structures of all these compounds have been established by IR, 1H NMR and mass spectral data

One pot synthesis of 3-acetoacetyl-5-oxo-5<i style="">H</i>-[1] benzopyrano [3,2-<i style="">e</i>]pyridin-2-one from triacetic acid lactone

2341-2345The nucleophilic character of triacetic acid lactone has been exploited here in the Michael condensation reaction involving 2-amino-3-formylchromone as the starting material. The reaction, as visualized, afforded yellow crystalline product 4. The compound has been characterized on the basis of spectral data and evaluated for antimicrobial activit

Synthesis and antibacterial evaluation of novel heterocycles from 5-chloro-3-methyl-1-phenylpyrazole-4-carbaldehyde

910-9175-Chloro-3-methyl-1-phenylpyrazole-4-carbaldehyde 1 reacts with acetylpyrone 2 and acetylbenzopyrone 3 via Claisen-Schmidt condensation to afford heterochalcones 4a,b which undergo facile cyclisation with hydrazines to give 3,5-heteroaryl-2-pyrazolines 5a-d in quantitative yield. Further, heterochalcones 4a,b undergo addition reaction using Br2/MeOH in the presence of Pb(NO3)2 or AgNO3 to afford addition products 6a,b. The structures of the newly synthesized compounds have been established on the basis of their spectral studies. The newly synthesized heterochalcones and pyrazolines have been screened for their antibacterial activity against two kinds of strains using the Agar well diffusion method. Some of the compounds showed significant activity against both the strains