β-Carboline Glucoalkaloids from Psychotria cupularis and Evaluation of Their Antileishmanial Activity

Purification of the crude ethanol extracts from leaves and stems of Psychotria cupularis (Mull.Arg.) Standl., Rubiaceae, resulted in the isolation of the known monoterpene indole alkaloids ophiorine B and lyalosidic and strictosidinic acids. The antileishmanial activity values found for the isolated compounds highlighted ophiorine B as the most active against Leishmania (Viannia) braziliensis (IC50 100.50 μg/ml or 196.1 μM) and Leishmania (Leishmania) amazonensis (IC50 3.69 μg/ml or 7.2 μM) with a selectivity index of 108.6 to the human acute monocytic leukemia THP-1 cells. To the best of our knowledge, this is the first time that antileishmanial β-carboline glucoalkaloids were isolated from the studied material plant, contributing to the pharmacological potential of the genus.