New indole alkaloid from Peschiera affinis (Apocynaceae).

A new indole alkaloid of the pyridocarbazole type, named 6N-hydroxy-olivacine, and two known compounds, 2N-oxide-olivacine and olivacine, were isolated from roots of Peschiera affinis. The structures of the compounds were determined by spectroscopic {IR and extensive NMR (COSY, HMQC, HMBCand NOESY)} and EIMS analysis.

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.

Total assignments of 1H and 13C NMR spectra of isocatalpanol and a derivative of tecomaquinone.

Isocatalpanol and tecomaquinone I were obtained from roots of Lippia sidoides, a medicinal plant from northeast Brazil. Reduction of tecomaquinone I with NaBH4 yielded a new derivative. Structural elucidation was done on the basis of spectral data, mainly by high-field NMR and electron ionization mass spectrometry.