[[[ Ethnopharmacological relevance: ]]] Annickia polycarpa leaf is an effective anti-malarial agent. However, its chemical constituents have not been isolated and assayed against any pathogen. [[[ Aim of the study: ]]] To isolate and characterize anti-malarial compound(s) from the leaf of A. polycarpa. [[[ Materials and methods: ]]] Bioassay-guided fractionation was employed to isolated the compound (AL1) from the chloroform fraction (ALCF) of the basified ethanol extract of A. polycarpa leaf (ALE). AL1 was characterized by LC-MS, 1D and 2D NMR spectroscopic analysis. Anti-malarial activity was evaluated against drug resistance Dd2 and drug sensitive 3D7 Plasmodium falciparum strains using the SYBR green assay. Cytotoxicity and mechanistic studies were determined using tetrazolium-based colorimetric assay and molecular docking respectively. [[[ Results: ]]] AL1 was characterized as n-hexyl 1-O-rutinoside. The IC_{50} values of ALE and ALCF against 3D7 and Dd2 P. falciparum strains ranges from 3.441 (0.3389) – 4.255 (0.2246) μg/mL. The IC_{50}s obtained for n-hexyl 1-O-rutinoside and Artesunate (standard drug) were 7.71 (0.5473) and 0.001 (0.00008) nM against the 3D7 parasite strain respectively. Also, the efficacy of n-hexyl 1-O-rutinoside increased by 24.40% against the chloroquine resistance Dd2 P. falciparum strain whiles that of Artesunate decreased by 98.96%. Furthermore, ALE, ALCF and n-hexyl 1-O-rutinoside were weakly cytotoxic to human RBCs with high selectivity indices. N-hexyl 1-O-rutinoside inhibits P. falciparum chloroquine resistance transporter (PfCRT) and dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) better than chloroquine and pyrimethamine respectively. But, produced similar inhibition of P. falciparum 2-trans-enoyl -ACP-reductase (PfERN) as triclosan. [[[ Conclusion: ]]] These results show that A. polycarpa leaf and n-hexyl 1-O-rutinoside possessed profound anti-malarial activity and are not cytotoxic. N-hexyl 1-O-rutinoside could therefore, be developed into a new anti-malarial medicine. This is the first study to report the anti-malarial activity of n-hexyl 1-O-rutinoside and its isolation from the genus Annickia.
【저자키워드】 Ethnopharmacological relevance: Annickia polycarpa leaf is an effective anti-malarial agent. However, its chemical constituents have not been isolated and assayed against any patho,