SN00799639, also known as SN639, is a potent inhibitor of the motility and development of parasitic larvae of Haemonchus contortus, a blood-feeding parasitic nematode of major economic importance in ruminants. SN639 displayed lower potency, with IC50 values of 8.4 μM (xL3 motility) and 0.29 μM (L4 development).