Species from genus Aspidosperma (Apocynaceae) are popularly employed to treat various diseases. This genus is characterized by the occurrence of indole alkaloids. Taking into account the various biological activities attributed to these alkaloids, the description of the chemical diversity in genus Aspidosperma is important. A review of simple carbolinic alkaloids isolated from species of various genera was published in 1979. In 1987, it was published another one dealing with the relationships between the chemical structures of the indole alkaloids and the evolution of Aspidosperma species. This work updates the information about the indole alkaloids isolated from Aspidosperma species.

O estudo fitoquímico das cascas do cerne de Aspidosperma nitidum permitiu o isolamento de um novo tipo de alcalóide indólico, contendo um sistema 1,2,9-triazabiciclo[7.2.1], que foi denominado braznitidumina 1. A caracterização de sua estrutura química foi realizada pela análises dos dados de IV, UV, ESI-EM e RMN de ¹H, 13C e 15N, empregando experimentos 1D e 2D (¹H ¹H COSY, ¹H ¹H NOESY, ¹H 13C HSQC e ¹H 13C HMBC). Pela análise do experimento ¹H ¹H NOESY, verificou-se que 1 apresenta uma conformação dobrada com aproximação entre os grupos indólico e imidazolidino-di-hidropirano. Essa configuração foi investigada por cálculos teóricos envolvendo otimizações de geometria (DFT/BLYP/6-31G*) para análise conformacional desse alcalóide, pela qual a distância entre os dois grupos mostrou-se compatível com as informações obtidas pelo experimento NOESY.

The phytochemical study of the stem bark of Aspidosperma nitidum led to the isolation of a new type of indole alkaloid with a 1,2,9-triazabicyclo[7.2.1] system, which has been called braznitidumine 1. The characterization of its chemical structure was carried out by IR, UV, ESIMS, and ¹H, 13C, and 15N NMR by using 1D and 2D (¹H ¹H COSY, ¹H ¹H NOESY, ¹H 13C HSQC and ¹H 13C HMBC) experiments. ¹H ¹H NOESY results showed that 1 presents a folded conformation with the approximation of the indole and the imidazolidine di-hydropyran groups. This configuration was investigated by theoretical calculations involving geometry optimization (DFT/BLYP/6-31G*) for the conformational analysis of this alkaloid. It confirmed the distance between the two groups in agreement with the NOESY experimental data.