title: Calycopterones and calyflorenones, novel biflavonoids from Calycopteris floribunda.
abstract: Neocalycopterone (1) and its methyl ether (2), along with two new biflavonoids, calyflorenones A (3) and B (4), were isolated from dried leaves of Calycopteris floribunda (Combretaceae). Structures 1-4 were investigated by spectroscopic methods. The relative stereochemistry of 3 and 4 was deduced through NOE and ROESY experiments, comparative CD and optical rotation evaluations. Cytotoxicity test results of 1 and 2 are reported. The monoflavonoid penduletin was isolated as a minor component from C. floribunda for the first time.
authors.affiliation: Pharmazeutisches Institut, Universität Bonn, Kreuzbergweg 26, D-53115 Bonn, Germany. r.mayer@uni-bonn.de
authors.forename: R
authors.initials: R
authors.lastname: Mayer
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D013057:Spectrum Analysis; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005419:Flavonoids