showed that the smaller tail fully resides in the PTR1 binding pocket (Figure ) and is stabilized by surrounding hydrophobic residues, not only in PTR1, but also in parasite DHFR (Figure ). Rigid-body docking studies suggested that the bulky naphthalene of 3c may be particularly beneficial in LmPTR1, since this target has a more elongated, open pocket compared to TbPTR1 (Figure ). The PABA moiety modifications are therefore suitable for modulating the compound interaction profile in a species-specific manner.