Obtenção de derivados da mistura triterpenoídica alfa- e beta-amirina / Obtention of derivatives from the alpha- and beta-amyrin triterpenoid mixture: 13C NMR data

Usando reações clássicas como esterificação e oxidação, uma série de derivados foi obtida a partir da mistura alfa- e beta-amirina, constituintes majoritários da resina de Protium heptaphyllum. Os compostos obtidos foram caracterizados por dados espectroscópicos como: IV, RMN de ¹H e de 13C e comparação com dados da literatura.

Using classic reactions such as esterification and oxidation, a series of derivatives was obtained from the alpha- and beta-amyrin mixture, major compounds of the Protium heptaphyllum resin. The obtained compounds were characterized by spectroscopic data such as: IR, ¹ H and 13C NMR and comparison with literature.

Quinones from plants of northeastern Brazil: structural diversity, chemical transformations, NMR data and biological activities.

The present review focus in quinones found in species of Brazilian northeastern Capraria biflora, Lippia sidoides, Lippia microphylla and Tabebuia serratifolia. The review cover ethnopharmacological aspects including photography of species, chemical structure feature, NMR datea and biological properties. Chemical transformations of lapachol to form enamine derivatives and biological activities are discussed.

Cytotoxic naphthoquinones from roots of Lippia microphylla.

A new prenylated naphthoquinone dimer named microphyllaquinone (1), a mixture of 6-methoxy- and 7-methoxy-naphtho[2,3-b]-furan-4,9-quinones (2a/2b) and tecomaquinone I (3), were isolated from roots of Lippia microphylla. The structures were elucidated by spectroscopic methods, including detailed 1D and 2D (COSY, NOESY, HMQC, HMBC) NMR data. Unpublished 13C NMR data of 2a and 2b are reported. The in vitro cytotoxic activity of the isolated compounds was tested against five types of tumor cells.