discaria/alkaloid

The isolation of the cyclopeptide alkaloids, adoutine-Y', discarine-B, discarine-E, and discarine-X, a new 14-membered cyclopeptide alkaloid from D. longispina, are reported. The structure of the new alkaloid was elucidated by spectroscopic methods and by chemical degradation.

The stereochemistry of discarines C (1) and D (2) and myrianthine A (3), three cyclopeptide alkaloids isolated from Discaria febrifuga, was determined by a combination of NMR studies of 1-3, enantioselective gas chromatography, and comparison of NMR data with those of synthetic tripeptides. For the

From the bark extract of Discaria febrifuga Mart. the known alkaloids frangufoline (I), adouétine (II), scutianine B (III), franganine (IV) and two new ones, discarine C (V) and D (VI), were isolated. Their structures are elucidated by degradation reactions and spectroscopic investigations.

On the basis of spectroscopic investigations (1H-NMR, 13C-NMR, UV, IR and MS spectroscopy), elemental analysis and degradation reactions the structure of a new alkaloid discarine G from the bark extract of Discaria febrifuga Mart. is elucidated.

The isolation and structure determination of cyclic peptide alkaloids, discarine-M and discarine-N, along with seven known cyclic peptide alkaloids, adouetine-Y', franganine, frangulanine, discarines-A, -B, -C, and -D from the root bark of Discaria americana are described. Structures were determined

The absolute configuration of franganine (1), a cyclopeptide alkaloid isolated from the methanol root bark extract of Discaria americana, was established on the basis of detailed NMR spectroscopic data and X-ray diffraction analysis of its salt (2).

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