Phytochemical investigation on the stems and roots of Tripterygium wilfordii led to the isolation and characterization of three new prenylated flavanones, tripteryols A-C (1-3), along with (±)-5,4'-dihydroxy-2'-methoxy-6',6″-dimethypyraro-(2″,3″:7,8)-6-methyflavanone (4), and ((2S)-5,7,4'-trihydroxy-2'-methoxy-8,5'-di(3-methyl-2-butenyl)-6-methylflavanone (5). Structures of the compounds 1-5 were elucidated using spectroscopic techniques, such as UV, IR, NMR (1D and 2D), and HRESI-MS. Tripteryols B (2) was found active in the antimicrobial assay against Cryptococcus neoformans, Pseudomonas aeruginosa, vancomycin-resistant Enterococcus faecalis (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) with IC50 values in the range of 2.95-8.59μg/mL. Compounds 4 and 5 showed significant antimicrobial activities against C. neoformans, MRSA and Staphylococcus aureus with IC50 values in the range of 1.06-2.60μg/mL. Additionally, significant antimalarial activities of tripteryols A-B (1-2) against chloroquine-sensitive D6 and resistant W2 clones of Plasmodium falciparum were observed and none of the compounds 1-5 were cytotoxic to Vero cells.
Keywords: Antimalarial; Antimicrobial; Celastraceae; Flavanone; NMR; Tripterygium wilfordii.
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