Five biflavonoids from Calycopteris floribunda (Combretaceae).

Pharmazeutisches Institut, Rheinische Friedrich-Wilhelms-Universität, Kreuzbergweg 26, D-53115 Bonn, Germany.
Phytochemistry (Impact Factor: 3.35). 04/2004; 65(5):593-601. DOI: 10.1016/j.phytochem.2004.01.001
Source: PubMed

ABSTRACT The structures of five biflavonoids, 6"-demethoxyneocalycopterone (1), calyflorenone C (2), 6"-epi-calyflorenone B (3), 6"-epi-calyflorenone C (4) and calyflorenone D (5) from the green parts of Calycopteris floribunda were established by NMR and MS. Their NMR and chiroptical properties (CD, [alpha]20D ) were compared with those of the known C. f. biflavonoids 6-11. Compound 1 represents a calycopterone derivative, 2-5 have a calyflorenone skeleton. With regard to one chiral center (C-6"), 4 and 3 are the respective epimers of 2 and 11.

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