title: Phytochemical and biological investigation of Begonia heracleifolia.
abstract: From the rhizomes of Begonia heracleifolia six known cucurbitacins ( 1- 6) were isolated. Based on spectral data (1D and 2D (1)H-, (13)C-NMR, ESI- and CI-MS) the structures were established as cucurbitacin B ( 1), cucurbitacin D ( 2), 23,24-dihydrocucurbitacin D ( 3), 23,24-dihydrocucurbitacin F ( 4), 2- O-beta-glucopyranosyl-cucurbitacin B ( 5), and 2- O-beta-glucopyranosyl-cucurbitacin D ( 6). Four of them ( 3- 6) were so far not reported as constituents of Begonia spp. Varyingly strong antiproliferative activity towards tumor and immune cells was observed for three compounds ( 1 - 3), due to different structural features.
authors.forename: B
authors.initials: B
authors.lastname: Frei
authors.forename: M
authors.initials: M
authors.lastname: Heinrich
authors.forename: D
authors.initials: D
authors.lastname: Herrmann
authors.forename: J E
authors.initials: JE
authors.lastname: Orjala
authors.forename: J
authors.initials: J
authors.lastname: Schmitt
authors.forename: O
authors.initials: O
authors.lastname: Sticher