Design, synthesis and SAR studies of 4-allyoxyaniline amides as potent 15-lipoxygensae inhibitors.

A group of 4-allyloxyaniline amides 5a-o were designed, synthesized and evaluated as potential inhibitors of soybean 15-lipoxygenase (SLO) on the basis of eugenol and esteragol structures. Compound 5e showed the best IC(50) in SLO inhibition (IC(50)=0.67+/-0.06 microM). All compounds were docked in SLO active site retrieved from RCSB Protein Data Bank (PDB entry: 1IK3) and showed that allyloxy group of compounds is oriented towards the Fe(3+)-OH moiety in the active site of enzyme and fixed by hydrogen bonding with two conserved His(513) and Gln(716). It is resulted that molecular volume of the amide moiety would be a major factor in inhibitory potency variation of the synthetic amides, where the hydrogen bonding of the amide group could also involve in the activity of the inhibitors.