Publications (25) View all
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Article: Oleanane glycosides from Astragalus tauricolus: Isolation and structural elucidation based on a preliminary liquid chromatography-electrospray ionization tandem mass spectrometry profiling.
Derya Gülcemal, Milena Masullo, Assunta Napolitano, Tamer Karayıldırım, Erdal Bedir, Ozgen Alankuş-Çalışkan, Sonia Piacente[show abstract] [hide abstract]
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 22μM against human leukemia cell line (U937). The other tested compounds, in a range of concentrations between 1 and 50μM, did not cause any significant reduction of the cell number.Phytochemistry 10/2012; · 3.35 Impact Factor -
Article: Saponins from Astragalus hareftae (NAB.) SIRJ.
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ABSTRACT: Four cycloartane- (hareftosides A-D) and oleanane-type triterpenoids (hareftoside E) were isolated from Astragalus hareftae along with fifteen known compounds. Structures of the compounds were established as 3,6-di-O-β-d-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (1), 3,6,24-tri-O-β-d-xylopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane (2), 3-O-β-d-xylopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),25(S)-epoxycycloartane (3), 16-O-β-d-glucopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),24(S)-epoxycycloartane (4), 3-O-[β-d-xylopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-β-d-glucuronopyranosyl]-soyasapogenol B (5) by the extensive use of 1D- and 2D-NMR experiments along with ESI-MS and HR-MS analyses.Phytochemistry 08/2012; · 3.35 Impact Factor -
Article: Secondary metabolites from the roots of Paronychia chionaea.
Sibel Avunduk, Ozgen Alankuş-Calişkan, Tomofumi Miyamoto, Chiaki Tanaka, Marie-Aleth Lacaille-Dubois[show abstract] [hide abstract]
ABSTRACT: Two novel secondary metabolites, compounds (1-2) were isolated from the roots of Paronychia chionaea. On the basis of spectroscopic data including 1D and 2D NMR experiments (COSY, TOCSY, HSQC, and HMBC), and mass spectroscopy, their structures were established as 6-C-[alpha-L-arabinopyranosyl-( 1 --> 2)-beta-D-glucopyranosyl]-7-O-[beta-D-glucopyranosyl]-luteolin 3'-methyl ether (1), and 2-(methoxy)-2-(3,5-dimethoxy 4-hydroxyphenyl)-ethane-1,2-diol 1-O-beta-D-glucopyranoside (2).Natural product communications 02/2011; 6(2):205-8. · 1.24 Impact Factor -
Article: Alpha-glucosidase inhibitory constituents of Linaria kurdica subsp. eriocalyx.
Irfan Aydoğdu, Figen Zihnioğlu, Tamer Karayildirim, Derya Gülcemal, Ozgen Alankuş-Calişkan, Erdal Bedir[show abstract] [hide abstract]
ABSTRACT: Three known iridoid glycosides, antirrhide (1), antirrhinoside (2), and 5-O-beta-allosylantirrhinoside (3), and two known flavone glycosides, linariin (4"'-O-acetylpectolinarin) (4) and linarin (acacetin-7-O-beta-D-rutinoside) (5) were isolated from Linaria kurdica Boiss & Hohen. subsp. eriocalyx. The structures of the isolated compounds were established from spectroscopic evidence. Compounds 1-3 showed high inhibitory potential against alpha-glucosidase.Natural product communications 06/2010; 5(6):841-4. · 1.24 Impact Factor -
Article: Monoterpenoid glucoindole alkaloids and iridoids from Pterocephalus pinardii.
Derya Gülcemal, Milena Masullo, Ozgen Alankuş-Calişkan, Tamer Karayildirim, Serdar G Senol, Sonia Piacente, Erdal Bedir[show abstract] [hide abstract]
ABSTRACT: A new secondary metabolite, pterocephaline, along with the known cantleyoside, 7alpha-morroniside, 3beta,5alpha-tetrahydrodesoxycordifoline lactam, 5S-5-carboxyvincoside, sweroside, and loganin have been isolated from the aerial parts of P. pinardii (Dipsacaceae). Moreover, cantleyoside-methyl-hemiacetal and cantleyoside-dimethyl-acetal were obtained as seco-iridoid artifacts. The structures were elucidated by extensive spectroscopic methods including 1D-((1)H, (13)C and TOCSY) and 2D-NMR (DQF-COSY, HSQC and HMBC). Monoterpenoid glucoindole alkaloids were encountered for the first time in Dipsacaceae family.Magnetic Resonance in Chemistry 03/2010; 48(3):239-43. · 1.44 Impact Factor