Antiprotozoal activity of aporphine alkaloids isolated from Unonopsis buchtienii (Annonaceae)

Abstract

On a preliminary screening, substantial leishmanicidal activity was observed for the petroleum ether and alkaloidal extracts of the stem bark of Unonopsis buchtienii, the alkaloids and sterols isolated from these were studied. Of the alkaloids, liriodenine exhibited the highest activity against Leishmania major and L. donovani (IC 100 = 3.12 mg/mL). On the other hand, O-methylmoschatoline and the petroleum ether extract without alkaloids showed an interesting in vitro activity against Trypanosoma brucei with an IC 100 of 6.25 mg/mL. The highest cytotoxic activities were found with the petroleum ether extracts without alkaloids and with all alkaloids isolated (IC 50`9 mg/mL for Vero cell line).

Antiprotozoal activity of major constituents from the bioactive fraction of Verbesina encelioides

“…This was also shown in compound 4 which has free hydroxyl groups at C-3 & C-16 as regard to compound 1. In addition, compounds 5 and 6 were inactive against all tested protozoa, this is in accordance with previous reports for antiprtozoal activity of sterols (Waechter et al 1999). All compounds were non-cytotoxic on MRC-5 cells (CC50 >64 µg/mL).…”

Oxoaporphine Alkaloids and Quinones from Stephania dinklagei and Evaluation of Their Antiprotozoal Activities

“…It is interesting, however, to point out that liriodenine (3) displayed the strongest activity (IC 50 = 15mM) against L. donovani promastigotes, and P. falciparum. The antileishmanial activity of 3 found in this study was in agreement with those previously reported (9). The tested compounds were devoid of activity towards L. donovani amastigote forms.…”

Leishmanicidal activity of fractions rich in aporphine alkaloids from Amazonian Unonopsis species

“…Liriodenine also presented significant activity against L. guyanensis and L. braziliensis (Costa et al, 2006). Another alkaloid in the genus Unonopsis described with leishmanicidal potential against promastigote forms of Leishmania in vitro assays is the bisaporphine alkaloid unonopsine (5) isolated from U. buchtienii (Waechter et al, 1999) and from the species synonymy of U. guatterioides, U. lindmanii (Siqueira et al, 1998). The present results demonstrate that both U. duckei and the U. guatterioides have a significant leishmanicidal activity.…”