Julocrotine,forms of Leishmania amazonensis (L.). In this work, the crystal structure of Julocrotine was solved by X-ray diffraction, and its geometrical parameters were compared with theoretical calculations at the B3LYP and HF level of theory. IR and NMR spectra also have been obtained and compared with theoretical calculations. IR absorptions calculated with the B3LYP level of theory employed together with the 6-311Gϩ(d,p) basis set, are close to those observed experimentally. Theoretical NMR calculations show little deviation from experimental results. The results show that the theory is in accordance with the experimental data.

RESUMO:O fracionamento do extrato hexânico do caule de um espécime de refl orestamento de Tectona grandis (Verbenaceae), através de procedimentos fi toquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-α-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fi toquímico de um espécime de refl orestamento de Tectona grandis, no Brasil, sendo o objetivo principal deste trabalho a comprovação da presença de tectoquinona em espécimes cultivados. Unitermos: Tectona grandis, Verbenaceae, espécime de refl orestamento, antraquinonas, naftoquinonasABSTRACT: "Anthraquinones and naphtoquinones from the bark of Tectona grandis (Verbenaceae) reforestation specimen". The hexane extract of the bark of Tectona grandis (Verbenaceae) afforded two anthraquinones and two naphtoquinones. Their caracterizations were obtained through NMR spectroscopic techniques. This is the fi rst phytochemical study of the bark of Tectona grandis reforestation specimen in Brazil. The main interest in this work is proving the presence of tectoquinone in reforestation specimen.

ABSTRACT:Aparisthman is a furan diterpenoid with a clerodane skeleton isolated from Aparisthmium cordatum (Juss.) Bail. (Euphorbiaceae). This natural product presents significant anti-ulcer activity to the level of cimetidine (Tagamet ), a compound used for the treatment of ulcers provoked by stress. The structure of X-ray diffraction of the aparisthman was compared with theoretical calculations and the results showed that the theory is in accordance with the experimental data. The infrared (IR) and nuclear magnetic resonance (NMR) spectra also were obtained and compared with theoretical calculations. The B3LYP theory level, with the 6-31G(d,p) basis set, leads the value to the IR absorption close to the value experimentally observed. NMR theoretical obtained with p) shows little deviation of experimental results. Calculations of molecular electrostatic potential and stabilization energies suggest that the protonation of aparisthman will be able to occur on carbonyl oxygen atom (O4).