Chemical constituents and leishmanicidal activity from leaves of Kielmeyera variabilis

Abstract

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.

Focus on PAINS: false friends in the quest for selective anti-protozoal lead structures from Nature?

“…40 Quercitrin was reported to have antiprotozoal activity (L. donovani: 17.7 μg mL −1 ; T. brucei rhodesiense: 27.9 μg mL −1 ; T. cruzi: >30 μg mL −1 ; L6: >90 μg mL −1 ), 38 and non-dose-dependent activity of isoquercitrin against L. amazonensis amastigotes (0.78-20 μg mL −1 , 40-45%) has been described recently. 41 Manjolin et al found the same mixed mechanism of inhibition as described above for fisetin 20 (L. donovani: 0.6 μg mL −1 ; T. brucei rhodesiense: 3.3 μg mL −1 ; T. cruzi: >30 μg mL −1 ; L6: 38.5 μg mL −1 ; 38…”

Phytochemical and Biological Studies on Persicaria Salicifolia Brouss. Ex Willd Growing in Egypt

“…These data indicated the presence of rutinose sugar moiety. The obtained 1 H and 13 CNMR data were compared to the reported data and the compound was identified as rutin (quercetin-3-O-α-L-rhamnosyl (1```à 6``) β-D-glucoside) 27 .…”

Antileishmanial in vitro activity of essential oil from Myrciaria plinioides, a native species from Southern Brazil

“…In this context, medicinal plants that have been applied in traditional remedies often represent promising sources of lead compounds for the development of new drugs (Oliveira et al, 2011). Within the last few years, considerable research interest has focused on screening plant extracts as potential sources of drugs for the treatment of leishmaniasis (Vila-Nova et al, Cota et al, 2012;Ramírez-Macías et al, 2012;Vila-Nova et al, 2012;Santos et al, 2013).…”