Anthraquinones with antiplasmodial activity from the roots of Rennellia elliptica Korth. (Rubiaceae).
Dichloromethane root extract of Rennellia elliptica Korth. showed strong inhibition of Plasmodium falciparum growth in vitro with an IC₅₀ value of 4.04 µg/mL. A phytochemical study of the dichloromethane root extract has led to the isolation and characterization of a new anthraquinone, 1,2-dimethoxy-6-methyl-9,10-anthraquinone (1), and ten known anthraquinones: 1-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone (2), nordamnacanthal (3), 2-formyl-3-hydroxy-9,10-anthraquinone (4), damnacanthal (5), lucidin-ω-methyl ether (6), 3-hydroxy-2-methyl-9,10-anthraquinone (7), rubiadin (8), 3-hydroxy-2-methoxy-6-methyl-9,10-anthraquinone (9), rubiadin-1-methyl ether (10) and 3-hydroxy-2-hydroxymethyl-9,10-anthraquinone (11). Structural elucidation of all compounds was accomplished by modern spectroscopic methods, notably 1D and 2D NMR, IR, UV and HREIMS. The new anthraquinone 1, 2-formyl-3-hydroxy-9,10-anthraquinone (4) and 3-hydroxy-2-methyl-9,10-anthraquinone (7) possess strong antiplasmodial activity, with IC₅₀ values of 1.10, 0.63 and 0.34 µM, respectively.
Osman
Che Puteh
CP
Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia.
Ismail
Nor Hadiani
NH
Ahmad
Rohaya
R
Ahmat
Norizan
N
Awang
Khalijah
K
Jaafar
Faridahanim Mohd
FM
D000818:Animals; D000880:Anthraquinones / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018517:Plant Roots / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects*; D019666:Rubiaceae / Q000033:anatomy & histology / Q000737:chemistry
D000880:Anthraquinones