jm010970c_si_003.pdf (1.17 MB)
Chemosensitization of a Multidrug-Resistant Leishmania tropica Line by New Sesquiterpenes from Maytenus magellanica and Maytenus chubutensis
journal contribution
posted on 2001-11-22, 00:00 authored by María L. Kennedy, Fernando Cortés-Selva, José M. Pérez-Victoria, Ignacio A. Jiménez, Antonio G. González, Orlando M. Muñoz, Francisco Gamarro, Santiago Castanys, Angel G. RaveloParasite resistance to drugs has emerged as a major problem in current medicine, and therefore,
there is great clinical interest in developing compounds that overcome these resistances. In an
intensive study of South American medicinal plants, herein we report the isolation, structure
elucidation, and biological activity of dihydro-β-agarofuran sesquiterpenes from the roots of
Maytenus magellanica (1−14) and M. chubutensis (14−17). This type of natural products may
be considered as privileged structures. The structures of 10 new compounds, 1, 3, 6−9, and
12−15, were determined by means of 1H and 13C NMR spectroscopic studies, including
homonuclear (COSY and ROESY) and heteronuclear correlation experiments (HMQC and
HMBC). The absolute configurations of eight hetero- and homochromophoric compounds, 1, 3,
6−9, 12, and 13, were determined by means of CD studies. Fourteen compounds, 1−3 and
6−16, have been tested on a multidrug-resistant Leishmania tropica line overexpressing a
P-glycoprotein-like transporter to determine their ability to revert the resistance phenotype
and to modulate intracellular drug accumulation. From this series, 1, 2, 3, 14, and 15 showed
potent activity, 1 being the most active compound. The structure−activity relationships of the
different compounds are discussed.