ABSTRACT
The chromatographic fractionation of the Mauritia flexuosa L. f., Arecaceae, leaves extract, a plant known by the name of buriti palm tree, resulted in the isolation of six flavonoids: tricin-7-O-rutinoside, apigenin-6-C-arabinoside, 8-C-glucoside (isoschaftoside), kaempferol-3-O-rutinoside (nicotiï¬orine), quercetin-3-O-rutinoside (rutin), luteolin-8-C-glucoside (orientin) and luteolin-6-C-glucoside (isoorientin). The flavonoids were found out and previously reported as constituents of the Arecaceae family plants, but the occurrence of C-glucoside flavonoids, in the species being analyzed, is described for the first time on this study. The structural elucidations of all of the isolated compounds were performed by means of the comparison of their spectral data (¹H and 13C NMR, UV and ESI-MS) with those ones of the literature.
ABSTRACT
Many phenolic compounds such as xanthones, quinones and coumarins have been isolated from Kielmeyera species; however the presence of flavonoids have been showed in other genera in the Calophylleae tribe as Caraipa, Mesua and Calophyllum. Six known glycosidic flavonoids: quercetin 3-β-O-galactopyranoside (1), quercetin 3-β-O-glucopyranoside (2), quercetin 3-O-α-rhamnoside (3), luteolin 6-C-β-glucopyranoside (4), isovitexin (5), kaempferol 3-O-α-rhamnoside (6) and one triterpene, lupenone (7) were isolated, for the first time, from organic crude extract of Kielmeyera variabilis Mart. & Zucc., Calophyllaceae, leaves. The crude organic extract from K. variabilis leaves exhibited 95% of leishmanidal activity at 20 µg/mL on amastigote-like form of Leishmania (Leishmania) amazonensis in vitro model and only compound 3 showed 40-45% of growth inhibition at concentration ranging from 0.78 to 20 µg/mL. In addition, quercetin 3-O-α-rhamnoside (quercitrin) was found to be the major metabolite. Our results and previous reports suggest that synergistic effects of flavonoid glycosides are the cause of significant leishmanidal activity of the crude organic extract from K. variabilis leaves.