Publications (29) View all
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Article: Isolation, Chemical and Free Radical Scavenging Characterization of Phenolics from Trifolium scabrum L. Aerial Parts.
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ABSTRACT: It was for the first time that Trifolium scabrum L. was researched for its phenolic profile. Sixteen phenolics (isoflavones and flavonoids) were isolated and identified in the aerial parts of Trifolium scabrum L. Their structures were established by ESI-MS (electrospray ionization-mass spectrometry) and NMR (nuclear magnetic resonance) techniques. Quantitative analysis of individual phenolics performed by means of UPLC-MS (ultra performance liquid chromatography-mass spectrometry) was based on calibration curves obtained for previously isolated standard compounds. Additionally free radical scavenging potential of these substances was assessed by means of a simple benchtop TLC-DPPH• (thin-layer chromatography-2,2-diphenyl-1-picrylhydrazyl radical) bioassay. Thus Trifolium scabrum L. can be regarded as a potential source of estrogenic and antioxidant compounds, both of significance in pharmaceutical as well as food industry. Our results show that Trifolium scabrum L. can be considered as natural and very good commercial source of phenolic compounds (mainly isoflavones).Journal of Agricultural and Food Chemistry 04/2013; · 2.82 Impact Factor -
Article: Iridoids, monoterpenoid glucoindole alkaloids andflavonoids from Vinca major
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ABSTRACT: A new secoiridoid glucoside, vinmajoroside (1), was isolated from the leaves of Vinca major L. along with 11 known compounds belonging to the secoiridoid ((7α)-7-O-methylmorroniside, 2), iridoid (loganin, loganic acid and 7-O-p-coumaroylloganin), monoterpenoid glucoindole alkaloid (5 (S)-5-carboxyvincoside and strictosamide), flavonoid (rutin, kaempferol 3-O-rutinoside and robinin), lignan (syringaresinol 4-O-β-glucopyranoside) and phenolic acid (chlorogenic acid) groups. The structure elucidation of the isolates was accomplished by extensive 1D and 2D-NMR experiments as well as ESI-MS. Secoiridoids and lignan were encountered for the first time in the genus VincaBiochemical Systematics and Ecology 01/2013; 49:69-72. · 0.93 Impact Factor -
Article: LC-ESI-MS quali-quantitative determination of phenolic constituents in different parts of wild and cultivated Astragalus gombiformis.
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ABSTRACT: High-performance liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) profiling of the MeOH extract of Astragalus gombiformis Pomel (Fabaceae) aerial parts guided the isolation of seven phenolic compounds among which 7-methylquercetin 3-O-α-l-rhamnopyranosyl-(1→2)-β-d-galactopyranoside (2) and 7-methylquercetin 3-O-α-l-rhamnopyranosyl-(1→2)-[6-O-(3-hydroxy-3-methylglutaryl)-β-d-galactopyranoside] (7) whose structures were elucidated by NMR and ESI-MS experiments. The radical scavenging activities of isolated compounds were investigated, by using the TEAC assay. Furthermore quantitative analyses were performed by LC-ESI-MS and applied to the comparative profiling of different parts (aerial parts, leaves and stems) of cultivated and wild A. gombiformis samples, confirming the interest of these compounds as markers of the species. Finally, a Principal Component Analysis was carried out in order to highlight the differences between different parts of cultivated and wild plants.Journal of pharmaceutical and biomedical analysis 01/2013; 72:89-98. · 2.45 Impact Factor -
Article: Oleanane glycosides from Astragalus tauricolus: Isolation and structural elucidation based on a preliminary liquid chromatography-electrospray ionization tandem mass spectrometry profiling.
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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: Revised structures of avenacosides A and B and a new sulfated saponin from Avena sativa L.
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ABSTRACT: The revised structures of avenacosides A and B and a new sulfated steroidal saponin isolated from grains of Avena sativa L. were elucidated. Their structures and complete NMR assignments are based on 1D and 2D NMR studies and identified as nuatigenin 3-O-{α-l-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-d-glucopyranoside}-26-O-β-d-glucopyranoside (1), nuatigenin 3-O-{α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→4)]-β-d-glucopyranoside}-26-O-β-d-glucopyranoside (2), and nuatigenin 3-O-{α-l-rhamnopyranosyl-(1→2)-[β-d-6-O-sulfoglucopyranosyl-(1→4)]-β-d-glucopyranoside}-26-O-β-d-glucopyranoside (3). Copyright © 2012 John Wiley & Sons, Ltd.Magnetic Resonance in Chemistry 09/2012; 50(11):755-8. · 1.44 Impact Factor
