NISCAIR Online Periodicals Repository Collection: IJC-B Vol.44B(04) [April 2005]

Isolation and hypotensive activity of five new phytoconstituents from chloroform extract of flowers of Hibiscus rosasinensis Linn.

Tue, 29 Mar 2005 22:58:59 GMT

Title: Isolation and hypotensive activity of five new phytoconstituents from chloroform extract of flowers of Hibiscus rosasinensis Linn.

Authors: Siddiqui, Anees A; Wani, Sachin M; Rajesh, R; Alagarsamy, V

Abstract: Three extracts of Hibiscus rosasinensis Linn have been prepared and studied for their hypotensive activity. Hydroalcoholic extract is found to exhibit prominent activity when compared to the reference standard minoxidil followed by chloroform extract. In an attempt to isolate the active constituents responsible for this activity, five new phytoconstituents have been isolated and their structures are elucidated from spectral evidence (IR, NMR and mass spectra). Hypotensive activity of these compounds is also studied.

Page(s): 806-811

Synthesis of novel naphtho[2,1-b]furo pyrazolyl, isoxazolyl and pyridyl derivatives as potential antimicrobial agents

Tue, 29 Mar 2005 22:58:59 GMT

Title: Synthesis of novel naphtho[2,1-b]furo pyrazolyl, isoxazolyl and pyridyl derivatives as potential antimicrobial agents

Authors: Mahadevan, K M; Basavaraj, K M; Mathias, D A Prathima; Vaidya, V P

Abstract: The treatment of chalcones 2a-f with substituted hydrazines in ethanol results in the formation of 3-(3-aminonaphtho[2,1-b]fur-2-yl)-5-arylpyrazolines 3a-l.The reaction of these chalcones 2a-f with hydroxylamine hydrochloride in presence of catalytic amount of hydrochloric acid affords 3-(3-aminonaphtho[2,1-b]fur-2-yl)-5-arylisoxazolines 4a-f. The synthesis of another biheterocycle, 2-amino-3-cyano-4-aryl-6-(3-aminonaphtho[2,1-b]fur-2yl)pyridines 5a-f is accomplished by reacting chalcones 2a-f with malanonitrile in presence of ammonium acetate. All the newly synthesized compounds are characterized by elemental analysis and spectral studies, and evaluated for antimicrobial activity.

Page(s): 789-793

Synthesis of biogenetically possible 2-phenyl-4-oxopyrano[2,3-]carbazoles

Tue, 29 Mar 2005 22:58:59 GMT

Title: Synthesis of biogenetically possible 2-phenyl-4-oxopyrano[2,3-]carbazoles

Authors: Vandana, T; Prasad, K J Rajendra

Abstract: Synthesis of 2-cinnamoyl-1-hydroxycarbazoles 2 by the condensation of 1-hydroxycarbazoles with aluminium chloride and phosphorousoxy chloride in good yield followed by acid catalysed cyclisation and dehydrogenation with DDQ to obtain the biogenetically possible 2-phenyl-4-oxopyrano[2,3- ]carbazoles 4 is described.

Page(s): 819-822

Synthesis and pharmacological evaluation of heterocycles from benzocycloheptenones

Tue, 29 Mar 2005 22:58:59 GMT

Title: Synthesis and pharmacological evaluation of heterocycles from benzocycloheptenones

Authors: Venkateswarlu, Peesapati; Vasireddy, Nageswara Rao

Abstract: A new series of benzocyclohepten-5-one thiosemicarbazones 2a,b obtained by condensation of benzocyclohepten-5-ones 1a,b with thiosemicarbazide, are treated with monochloroacetic acid, 3-bromopropionic acid, chloroacetyl chloride, 1,3-dichloroacetone, phenacyl bromide and acetic anhydride, respectively to yield nitrogen and sulphur containing heterocycles. The structures of all these compounds have been determined by analytical and spectral methods. A few of them exhibit promising antibacterial activity.

Page(s): 783-788