Identificação de alcaloides aporfínicos, oxoaporfínicos, tetraidroprotoberberínicos e benziltetraisoquinolínicos por desreplicação das cascas de Unonopsis duckei

Abstract

The species Unonopsis duckei R. E. Fr. belongs to the Annonaceae family and is found in the states of Amazonas, Pará and Rondônia. The genus to which it belongs (Unonopsis) is described as neotropical consisting of trees and shrubs, currently having 47 registered species, 25 of which are considered relatively new. Its distribution in the national territory is endemic to the northern region with 15 species recorded for this region. From previous studies, isoquinoline alkaloids were identified in this species. Due to the great pharmacological potential, the interest and search for new alkaloids has become greater. For this reason, the objective of this work was to investigate the presence of alkaloids not yet reported in this species, based on the characterization of the alkaloid fraction of its bark using mass spectrometry. The analyzes carried out allowed the preliminary identification of 12 alkaloids. Among them, it was possible to classify them into aporphine, oxoaporphine, tetrahydroprotoberberine and benzyltetrahydroisoquinoline, namely: seven aporphine alkaloids, anonaine (1), asimilobine (2), nornuciferine (3), isopiline (4), isocoridine (5), glaucine ( 6) and boldine (7); three oxoaporphines, liriodenine (8), oxoputerine (9) and lisicamine (10); a tetrahydroprotoberberine, tetrahydropalmatine (11) and a benzyltetrahydroisoquinolinic phenol, 2-methoxy-5-[(5,6,7,8-tetrahydro-1,3- dioxolo[4,5-g]isoquinolin-5-yl)methyl] - (9Cl, ACl) (12). Among these, the alkaloids isopiline (4), isocoridine (5), boldine (7), oxoputerine (9) and tetrahydropalmatine (11) stand out, reported for the first time in the species. Even more important is the alkaloid benzyltetrahydroisoquinolinic phenol, 2-methoxy-5-[(5,6,7,8- tetrahydro-1,3-dioxolo[4,5-g]isoquinolin-5-yl)methyl] - (9Cl - ACl) (12) which is reported for the first time as a natural product. Such results reveal the chemotaxonomic importance of the species and open spaces for new explorations not only of the species, but also of the genus in question.