ABSTRACT
Four dimeric chalcone derivatives, 8â³,9â³-dihydrowelwitschin H, uvarins A-C, a naphthalene derivative, 2-hydroxy-3-methoxy-6-(4'- hydroxyphenyl)naphthalene, and the known dimeric chalcones, dependensin and welwitschin E, flavonoids, a cyclohexane oxide derivative, an aromatic aldehyde were isolated from the roots of Uvaria siamensis (Annonaceae). The structures of the compounds were elucidated by spectroscopic analysis, as well as by comparison with literature data. The isolated compounds with a sufficient amount for biological assays were evaluated for their antimalarial, antimycobacterial, and cytotoxic activities. The dimeric chalcones 8â³,9â³-dihydrowelwitschin H, uvarins B and C, dependensin and welwitschin E showed strong antiplasmodial activity with IC50 values of 3.10, 3.02, 3.09, 4.21 and 3.99 µg/mL, respectively. A possible biosynthesis pathway of the dimeric chalcones is discussed.
Subject(s)
Antimalarials/isolation & purification , Antimalarials/pharmacology , Chalcones/pharmacology , Plant Roots/chemistry , Uvaria/chemistry , Anti-Bacterial Agents/pharmacology , Antimalarials/chemistry , Chalcones/chemistry , Chalcones/isolation & purification , Flavonoids/chemistry , Flavonoids/isolation & purification , Flavonoids/pharmacology , Inhibitory Concentration 50 , Molecular StructureABSTRACT
A novel anthraquinone, 1,3-dihydroxy-5,6-dimethoxy-2-methoxymethyl-9,10-anthraquinone (9) and a new natural product, 2-hydroxymethyl-1-methoxy-9,10-anthraquinone (8) were isolated from the roots of Prismatomeris malayana together with seven known anthraquinones, tectoquinone (1), 1-hydroxy-2-methyl-9,10-anthraquinone (2), rubiadin (3), rubiadin-1-methyl ether (4), 1,3-dihydroxy-5,6-dimethoxy-2-methyl-9,10-anthraquinone (5), nordamnacanthal (6), and damnacanthal (7). Their structures were determined on the basis of spectroscopic data. Some of the anthraquinones were tested for anticancer, antifungal, and antimalarial activities.
