title: Cucurbitane-type triterpenes with anti-proliferative effects on U937 cells from an egyptian natural medicine, Bryonia cretica: structures of new triterpene glycosides, bryoniaosides A and B.
abstract: The 90% aqueous ethanol extract of an Egyptian natural medicine, the roots of Bryonia cretica L., was found to exhibit a strong inhibitory effect on the proliferation of human leukemia U937 cells. By bioassay-guided fractionation, we isolated two new cucurbitane-type triterpene glycosides, bryoniaosides A and B, were isolated from the roots of Bryonia cretica L. together with 16 known cucurbitane-type triterpenes and glycosides. The chemical structures of bryoniaosides A and B were determined on the basis of chemical and spectroscopic evidence. Effects of principal cucurbitane-type triterpenes (cucurbitacins B, D, E, and J, 23,24-dihydrocucurbitacins B and E, and hexanorcucurbitacin D) on proliferation of the cells were examined. Cucurbitacins B and E showed the greater cytotoxic effects with IC(50) values of 9.2 and 16 nM after 72 h, and their IC(50) values were equivalent to that of camptothecin. An alpha,beta-conjugated ketone moiety at the 22-24-positions and an acetoxy group at the 25-position are essential for the strong activity.
authors.affiliation: Kyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Souichi
authors.initials: S
authors.lastname: Nakashima
authors.forename: Osama Bashir
authors.initials: OB
authors.lastname: Abdel-Halim
authors.forename: Toshio
authors.initials: T
authors.lastname: Morikawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D029772:Bryonia / Q000737:chemistry*; D049109:Cell Proliferation / Q000187:drug effects; D004534:Egypt; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D007938:Leukemia / Q000188:drug therapy; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D020298:U937 Cells
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D006027:Glycosides; D010936:Plant Extracts; D014315:Triterpenes; C551761:bryoniaoside A; C551762:bryoniaoside B; C514277:cucurbitane