Phytochemical and biological study of Vernonia tweediana Baker (Asteraceae)

A mistura de α-amirina, β-amirina e lupeol e o ácido palmítico puro foram os principais constituintes químicos isolados do extrato clorofórmio da parte aérea de V. tweediana. Lupenil palmitato puro e a mistura de α-amiril palmitato e β-amiril palmitato foram isolados a partir do extrato clorofórmio das raízes. As estruturas foram caracterizadas por métodos químicos e espectroscópicos. Também foram investigadas as atividades biológicas dos extratos hexano, clorofórmio, acetato de etila e metanol das partes aéreas e raízes de V. tweediana. Os extratos mostraram atividades boas a moderadas.The mixture of α-amyrin, β-amyrin and lupeol and pure palmitic acid were the main constituents isolated from chloroform extract of the aerial part of V. tweediana. Pure lupenyl palmitate and a mixture of α-amyril palmitate and β-amyril palmitate were isolated from chloroform extract of the roots. Their structures were established by chemical and spectroscopic methods. The biological activities of the hexane, chloroform, ethyl acetate and methanol extracts of the aerial parts and roots from V. tweediana were also investigated. The extracts showed good to moderated activities.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Qualitative determination of indole alkaloids of Tabernaemontana fuchsiaefolia (Apocynaceae)

This paper describes a fast and efficient procedure to separate and identify indole alkaloids from the ethanolic extract of Tabernaemontana fuchsiaefolia (Apocynaceae). The alkaloidal fractions obtained from ethanolic extracts of leaves and stem barks and root barks were fractioned and analyzed by Thin-Layer Chromatography (TLC) and by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The following indole alkaloids were identified: ibogamine, coronaridine, ibogaine pseudoindoxyl, voacangine hydroxyindolenine, voacangine pseudoindoxyl, tabernanthine, catharanthine, voacangine, 19-oxovoacangine, 10-hydroxycoronaridine, affinisine, 16-epi-affinine, voachalotine, ibogaline, and conopharyngine

Triterpenic acids from Eugenia moraviana

A novel triterpene, characterized as 6alpha-hydroxybetulinic acid, was isolated from the leaves and stems of Eugenia moraviana (Myrtaceae), known in Brazil as Cambuí, together with three known compounds, platanic acid, betulinic acid and beta-sitosterol. Unequivocal ¹H and 13C assignments of 6alpha-hydroxybetulinic acid (3beta,6alpha-dihydroxy-20(29)-lupen-28-oic acid) and platanic acid were undertaken by spectral analysis including NOE and 2 D NMR experiments