title: Oleanane glycosides from Astragalus tauricolus: isolation and structural elucidation based on a preliminary liquid chromatography-electrospray ionization tandem mass spectrometry profiling.
abstract: As a part of our ongoing research for bioactive compounds from Turkish Astragalus species, the investigation of Astragalus tauricolus has been carried out. An approach based on HPLC-ESIMS(n) experiments has been used to profile the triterpene glycosides occurring in the butanol extract of the whole plant. On the basis of the results of the online screening by HPLC-ESIMS(n), 22 oleanane-type triterpene glycosides, including ten compounds never reported before, were isolated, and their structures were established by the extensive use of 1D and 2D-NMR experiments along with ESIMS and HRMS analysis. Noteworthy, cycloartane-type triterpene glycosides, the main constituents of Astragalus spp., were not found. This peculiar feature characterizes a very limited group of Astragalus spp. The antiproliferative activity of the isolated compounds 1-12, 15, 17-19 was evaluated against a small panel of cancer cell lines. Only compound 11 showed an IC(50) of 22 μM against human leukemia cell line (U937). The other tested compounds, in a range of concentrations between 1 and 50 μM, did not cause any significant reduction of the cell number.
authors.affiliation: Chemistry Department, Faculty of Science, Ege University, 35100 Bornova, Izmir, Turkey.
authors.forename: Derya
authors.initials: D
authors.lastname: Gülcemal
authors.forename: Milena
authors.initials: M
authors.lastname: Masullo
authors.forename: Assunta
authors.initials: A
authors.lastname: Napolitano
authors.forename: Tamer
authors.initials: T
authors.lastname: Karayıldırım
authors.forename: Erdal
authors.initials: E
authors.lastname: Bedir
authors.forename: Ozgen
authors.initials: O
authors.lastname: Alankuş-Çalışkan
authors.forename: Sonia
authors.initials: S
authors.lastname: Piacente
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006027:Glycosides / Q000737:chemistry*; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D006027:Glycosides; C413246:oleanane; D009828:Oleanolic Acid