RESUMO
From a CH2Cl2 extract of the bark of Taxus wallichiana, six new taxoids, wallitaxanes A-F (1-6), were isolated, together with 29 known compounds. The structures of the new compounds were elucidated on the basis of spectroscopic data interpretation. Wallitaxane D (4) was identified as an opened oxetane-type taxoid having the first naturally occurring C(H)-20 acetal group, while wallitaxanes E (5) and F (6) are representative of the rare abeo-taxoid class. The isolated compounds were evaluated for their α-glucosidase inhibitory activity and for cytotoxicity against the HeLa human cervical cancer cell line. In the present work, taxanes were found to exhibit α-glucosidase inhibitory activity for the first time, and wallitaxane A (1) showed the most potent effect, with an IC50 value of 3.6 µM. In turn, 7-epi-taxol (16) and 7-epi-10-deacetyltaxol (17) showed IC50 values of 0.05 and 0.085 nM, respectively, against HeLa cells.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Hidrocarbonetos Aromáticos com Pontes/química , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/farmacologia , Casca de Planta/química , Taxoides/isolamento & purificação , Taxoides/farmacologia , Taxus/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Diterpenos/química , Inibidores de Glicosídeo Hidrolases/química , Humanos , Estrutura Molecular , Paclitaxel/farmacologia , Taxoides/química , alfa-GlucosidasesRESUMO
A method for the synthesis of 2-aryl(alkyl)aminopyrimidines from readily available 3,4-dihydropyrimidin-1H-2-thiones (DHPMs) via dehydrosulfurative C-N cross-coupling and concomitant oxidative dehydrogenation under a Pd/Cu catalytic system is described. This reaction protocol provides unprecedented diversity of fully substituted 2-aryl(alkyl)aminopyrimidines in a single step from a wide range of DHPMs and amine coupling partners.
