HPLC-Based Activity Profiling for Antiprotozoal Compounds in and .

In a screening of Sudanese medicinal plants for antiprotozoal activity, the chloroform fractions obtained by liquid-liquid partitioning from ethanolic extracts of fruits of var. and stems of Roth ex Schult. exhibited activity against axenically grown amastigotes. This antileishmanial activity was localized by HPLC-based activity profiling. Targeted preparative isolation afforded flavonoids -, 3-methoxy-4-hydroxybenzoic acid (), and benzyltetrahydroisoquinoline alkaloids laudanine () and laudanosine () from , and pinoresinol (), isorhamnetin (), (-)-pseudosemiglabrin (), and kaempferol () from The antiprotozoal activity of - against (axenic and intracellular amastigotes), (bloodstream forms), and (erythrocytic stages), and the cytotoxicity in L6 murine myoblast cells were determined . Quercetin-3,7-dimethylether () showed the highest activity against axenic (IC 4.5 µM; selectivity index [SI], 12.3), (IC 7.3 µM; SI, 7.6), and (IC, 2.4 µM; SI, 23.2). The congener ayanin () exhibited moderate antileishmanial (IC, 8.2 µM; SI, 12.2), antiplasmodial (IC, 7.8 µM; SI, 12.9), and antitrypanosomal activity (IC, 11.2 µM; SI, 8.9). None of the compounds showed notable activity against the intramacrophage form of .