Anti-protozoal and plasmodial FabI enzyme inhibiting metabolites of Scrophularia lepidota roots

Nine iridoid glycosides, two of which (8, 9) are new, an iridoid-related aglycone (10) and a phenylethanoid glycoside, angoroside C (11), were isolated from the roots of S. lepidota. Compound 9 showed remarkable leishmanicidal activity (IC50 6.1 μg/ml), while 10 exhibited anti-malarial (40.6 g/ml) and plasmodial FabI inhibitory potential (IC50 100 μg/ml). 10 is the second anti-malarial natural product targeting the FabI enzyme of Plasmodium falciparum.