Calycopterones and calyflorenones, novel biflavonoids from Calycopteris floribunda
Mayer, R.
Journal of Natural Products 62(9): 1274-1278
1999
ISSN/ISBN: 0163-3864 PMID: 10514312 Document Number: 498787
Neocalycopterone and its methyl ether, along with 2 new biflavonoids, calyflorenones A and B, were isolated from dried leaves of C. floribunda [Getonia] (collected from India in 1991). Their structures were determined from spectral data. The relative stereochemistry of calyflorenones A and B was deduced through NOE and ROESY experiments, comparative CD and optical rotation evaluations. Neocalycopterone and its methyl ether exhibited broad, unspecific cytotoxicity against a battery of human cancer cell lines. The monoflavonoid penduletin was isolated as a minor component from C. floribunda for the first time.