Novel δ2-isoxazolines as group II phospholipase A2 inhibitors

The synthesized imidazolyl substituted δ2-isoxazolines were subjected to Phospholipase A2 (PLA2) enzyme inhibitory activity against snake venom source and their structure–activity relationship with respect to different groups attached to this moiety is reported for the first time. The crystal structure of the compound 2-butyl-5-chloro-3H-imidazolyl-4-carbaldehyde oxime 2, an intermediate for the construction of isoxazolines is reported. These compounds exerted a significant PLA2 enzyme inhibitory activity against group II PLA2. The in vivo activity on mice of selected compounds 3bI and 3bIV shows the comparable anti-inflammatory activity with the known standard ursolic acid.