A series of novel tetra substituted
thiophenes were synthesized, characterized, and evaluated for their anti-inflammatory activity in
carrageenin induced rat paw
edema model-an acute in vivo model. Compounds V1, V3, V11, V12, V17, and V18 showed good anti-inflammatory activity, indicating the importance of
oxime moiety in modulating the activity. The structure-activity relationship studies explore "the aliphatic
oxime esters" attached via a
ketone bridge to fifth position of the
thiophene, and indicate that this feature may enhance the anti-inflammatory activity as compared to aromatic
oximes. Since
free radicals are implicated in various inflammatory disorders, the
free radical scavenging activity of some of the synthesized candidates was assessed using 1,1-diphenyl-2-picryl hydrazyl assay. The
oxime containing analogs exhibited weak to moderate activity as
free radical scavengers in DPPH assay. A plausible reasoning for its
free radical scavenging ability is discussed. All the compounds were also screened in nitro blue tetrazolium model, to assess them as
superoxide anion radical scavengers. A direct correlation between anti-inflammatory activity and
free radical scavenging activity was not seen. The results disclose a new class of
anti-inflammatory agents designed and synthesized for the first time wherein the utility of aliphatic
oxime esters in modulating the anti-inflammatory activity profile is apparent. This will give us potential anti-inflammatory leads.