RESUMEN
Two new cyclopeptides, named discarene C (1) and discarene D (2), have been isolated from the bark of Discaria americana, along with seven known cyclopeptide alkaloids. The structures of the new compounds were determined by spectroscopic methods, mainly NMR. The stereochemistry of the ring amino acid residues have been assigned by gas chromatography employing modified cyclodextrins as chiral stationary phases.
Asunto(s)
Alcaloides/aislamiento & purificación , Péptidos Cíclicos/aislamiento & purificación , Plantas Medicinales/química , Alcaloides/química , Brasil , Cromatografía de Gases , Cromatografía en Capa Delgada , Leucina/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Péptidos Cíclicos/química , Fenilalanina/química , Raíces de Plantas/química , Espectrofotometría Infrarroja , EstereoisomerismoRESUMEN
Two diterpenoids, humirianthol and acrenol, as well as the known annonalide, were isolated from Humirianthera ampla. Humirianthol and acrenol were determined by 1D and 2D NMR spectroscopic techniques to be 3 beta,20:14 beta,16-diepoxy-3 alpha, 15 alpha-dihydroxy-7-pimaren-19,6 beta-olide and 3 beta,20-epoxy-3 alpha,15,16-trihydroxy-7-pimaren-19,6 beta-olide, respectively.