Cyclopeptides from the bark of Discaria americana

Two new cyclopeptides, named discarene C (1) and discarene D (2), have been isolated from the bark of Discaria americana, along with seven known cyclo peptide alkaloids. The structures of the new compounds were determined by s pectroscopic methods, mainly NMR. The stereochemistry of the ring amino aci d residues have been assigned by gas chromatography employing modified cycl odextrins as chiral stationary phases.