One new aporphine, dicentrine-β-
N-oxide ( 1 ), together with five related known alkaloids dehydrodicentrine ( 2 ), predicentrine ( 3 ),
N-methyllaurotetanine ( 4 ), cassythicine ( 5 ), and dicentrine ( 6 ) were isolated from the leaves of
Ocotea puberula (Lauraceae). Antiprotozoal activity of the isolated compounds was evaluated
in vitro against trypomastigote forms of
Trypanosoma cruzi. Among the tested compounds, alkaloid 1 exhibited higher potential with EC
50 value of 18.2 μM and reduced toxicity against NCTC cells (CC
50>200 μM – SI>11.0), similar to positive control benznidazole (EC
50 of 17.7 μM and SI=10.7). Considering the promising results of dicentrine-β-
N-oxide ( 1 ) against trypomastigotes, the mechanism of parasite death caused by this alkaloid was investigated. As observed, this compound reached the plasma membrane electric potential directly after 2 h of incubation and triggered mitochondrial depolarization, which probably leads to trypomastigote death. Therefore, dicentrine-β-
N-oxide ( 1 ), reported for the first time in this work, can contribute to future works for the development of new trypanocidal agents.
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