Browsing by Autor "Gabriela M. Cabrera"

Filter results by typing the first few letters
Now showing 1 - 1 of 1
  • Thumbnail Image
    Item type: Item ,
    Leishmanicidal Constituents from the Leaves of <i>Piper rusbyi</i>
    (Thieme Medical Publishers (Germany), 2007) Ninoska Flores; Gabriela M. Cabrera; Ignacio A. Jiménez; José E. Piñero; Alberto Giménez; Geneviève Bourdy; Fernando Cortés-Selva; Isabel L. Bazzocchi
    The kavapyrone (+)-(7 R,8 S)-epoxy-5,6-didehydrokavain (1) and the chalcone flavokavain B (2) were isolated from Piper rusbyi as the bioactive components by bioassay-guided fractionation, using an in vitro assay against promastigote forms of three Leishmania strains. In addition, the new kavapyrone, (7 R,8 R/7 S,8 S)-dihydroxy-5,6-didehydrokavain (3), which is very likely an artifact, and four known compounds (4-7) were isolated. Their structures were elucidated on the basis of spectral analysis, and the absolute configurations of compounds 1 and 3 were established by CD studies and the modified Mosher ester procedure, respectively. All compounds were evaluated for in vitro leishmanicidal activity. The most active compounds 1 (IC50=81.9 microM) and 2 (IC50=11.2 microM) were also evaluated in vivo against a New World strain of cutaneous leishmaniasis, and the results showed the efficacy of 2 at a dose of 5 mg/kg/day. Compounds 1 and 3 were also assayed as reversal agents against a multidrug-resistant Leishmania tropica line, but were found to be inactive.