Varshney H. M., Rajnish kumar, Shailender Mohan

 A novel series of 3-hydroxy-2-(substituted phenyl)-4H-chromen-4-one derivatives(IIa-d) were synthesized by Algar-Flym-Oyamada reactions, o-hydroxy acetophenone and substituted aromatic aldehyde were reacted in ethanol followed by addition of sodium hydroxide (40%) which leads to the formation of substituted chalcone (Ia-d). synthesized compounds (Ia-d) were further reacted with ethanol, sodium hydroxide and hydrogen peroxide for 2-3 hours at room temperature which give the titled compound 3-hydroxy-2-(substituted phenyl)-4H-chromen-4-one(IIa-d). The structures of all these compounds have been established on the basis of analytical and spectral data. Synthesized compounds were characterized by their IR, 1H-NMR, elemental and mass spectroscopic data.  Synthesized compounds were then screened for anti-oxidant, anti-inflammatory and ulcerogenic activity. The anti-oxidant activity was performed by DPPH free radical scavenging method using ascorbic acid as standard and compound IIa, IIc and IId showed significant free radical scavenging activity. The anti-inflammatory activity was performed using carrageenan induced rat paw edema method and compound IIa and IId showed most significant anti-inflammatory activity. The acute ulcerogenic activity was performed on albino-wistar rats by ceoli et al method using aspirin as standard drug.  Among the synthesized compounds only IId was found to have significant antioxidant and potential anti-inflammatory activity with no ulcerogenic effect. Among the synthesized compounds significant activity were shown by the compounds having substitution such as- 4-nitro, 3-nitro and 2, 6-dichloro respectively on the phenyl ring of the flavonol nucleus.
Keywords: Antioxidant, anti-inflammatory, flavonol, ulcerogenic.