Multifunctional toxin phospholipase A2 (PLA2) in Naja oxiana venom, a promising target for 2,5-disubstituted-1,3,4-oxadiazole derivatives

The present work is designed to synthesize 2,5-disub­stituted-1,3,4-oxadiazole derivatives 5a–5d as snake venom phospholipase A2 (PLA2) inhibitors. The snake venom was isolated from Naja oxiana by pressing their glands below eyes to perform anti-PLA2 activity. The compounds 5a–5d showed good PLA2 inhibitory potential, especially 5d exhibited excellent activity having IC50 value 0.002 mM (0.01 > p > 0.001) followed by 5c having IC50 value 0.003 mM (0.01 > p > 0.001). Compounds 5a and 5b have IC50 values 0.027 mM (p < 0.001) and 0.014 mM (p < 0.001) respectively. The docking results showed that all compounds have binding interactions with amino acid residues in active binding site. They have good binding affinities, particularly 5d has binding energy –6.8 kcal/mol compared to other analogues. On the basis of dry and wet lab results, it may proposed that 5d may act as a potent inhibitor of PLA2 in N. oxiana venom.