Estudo Fitoquímico de Peschiera affinis (Müell. Arg.) Miers

Abstract

Peschiera a±nis is a shrub of the Apocynace½ family, popularly known as em- pigeira", gr~ao de bode", gr~ao de porco" in diverse parts of the Brazil and as gr~ao de galo" in the state of the Cear¶a. It is rich specie in indole alkaloids, which show diverse biological activities such as anti-tumor, anti-microbial, anti-hypertensive, contraceptive and so on. Previous phytochemical investigations reports indole alkaloids type iboga, sarpagine, vobasine, beyond alkaloids of the type pyridocarbazole and ter-penoids. The present work deals with to the phytochemical study of the roots and stem of P. a±nis. The chromatographic analysis of extracts hexanic and etanolic of the roots and the etanolic extract of the stem allowed to the isolation and identi¯cation of ten chemical constituent, the alkaloids: olivacine, peschienine, N-hydroxy-peschienine, voacangine, mixture of indole alkaloids a±nisine and iboxygaine, olivacine Nb-oxide, isovoacristine hydroxyindolenine, voacangine, mixture of the type iboga alkaloids of voacangine and coronaridine and the mixture of terpenoids ®-amirine and ¯-amirine acetates. Structural determination of compounds were done by the spectrometrics techniques including IR,EM,1 H and 13C NMR including techniques (COSY,HMQC,HMBC,NOESY) and still, comparison with described spectrometrics data in literature. The ®-amirine and ¯-amirine acetates and olivacine Nb-oxide are reported for the first time in this species while that the alkaloids peschienine, N-hydroxy-peschienine and isovoacristine hydroxyindolenine are new substances. Quanti¯cation of the olivacine alkaloid was done by the alkaloidic fraction of etanolics extracts of the roots and stem by means of HPLC. Extracts and pure compounds were avaluated for scavenger activity using ¯-carotene and DPPH (2,2-diphenyl-1-picrylhidrazyl) bioassay and results showed signi¯cant activity for alkaloid PA-9 and fraction alkaloidic and PA-8 showed an average activity.