Isolation of secondary metabolites from Hortia oreadica (Rutaceae) leaves through high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) with a two-phase solvent system (hexane-ethanol-acetonitirile-water 10:8:1 : 1, v/v) was applied to examine the leaves of Hortia oreadica, which afforded the known limonoid guyanin (1), the alkaloids rutaecarpin (2) and dictamnine (6). the dihydrocinnamic acid derivatives methyl 5,7-dimethoxy-2,2-dimethyl-2H-1-benzopyran-6-propanoate (3), 5,8-dimethoxy-2,2-dimethyl-2H-1-benzopyran-6-propanoic acid (4), together with the new E-3,4-(dimethoxy-alpha(3-hydroxy-4-carbomethoxyphenyl)cinnamic acid acid (5). The recovery of compounds 1-6 was determined by comparison with LC-atmospheric pressure chemical ionization MS/MS data: 66.2%, 93.1%. 102.5%, 101.2%, 99.0% and 84.9%, respectively. Compound 3 showed IC50 of 23.6 mu M against Plasmodium falciparum and 15.6 mu M against Trypanosoma brucei rhodesienses and was not toxic to KB cells (IC50 > 100 mu M). (C) 2009 Elsevier B.V. All rights reserved.