Five biflavonoids from Calycopteris floribunda (Combretaceae).
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.
Mayer
Ralf
R
Pharmazeutisches Institut, Rheinische Friedrich-Wilhelms-Universität, Kreuzbergweg 26, D-53115 Bonn, Germany. r.mayer@uni-bonn.de
D044946:Biflavonoids / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D002942:Circular Dichroism; D029764:Combretaceae / Q000737:chemistry* / Q000378:metabolism; D013058:Mass Spectrometry; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
D044946:Biflavonoids