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Papers by Virginia Dimaki

Research paper thumbnail of GC-MS and LC-DAD-MS Phytochemical Profiling for Characterization of Three Native Salvia Taxa from Eastern Mediterranean with Antiglycation Properties

Molecules

Salvia fruticosa and S. pomifera subsp. calycina are native to Eastern Mediterranean and S. pomif... more Salvia fruticosa and S. pomifera subsp. calycina are native to Eastern Mediterranean and S. pomifera subsp. pomifera is endemic to Greece. The primary aim of this study was to develop an analytical methodology for metabolomic profiling and to study their efficacy in combating glycation, the major biochemical complication of diabetes. After sequential ultrasound-assisted extraction of 2 g of leaves with petroleum ether and 70% methanol, the volatile metabolites in the petroleum ether extracts were studied with GC-MS (Gas Chromatography-Mass Spectrometry), whereas the polar metabolites in the hydroalcoholic extracts were determined and quantified by UHPLC-DAD–ESI-MS (Ultra-High Performance Liquid Chromatography–Diode Array Detector–Mass Spectrometry). This methodology was applied to five populations belonging to the three native taxa. 1,8-Cineole was the predominant volatile (34.8–39.0%) in S. fruticosa, while S. pomifera had a greater content of α-thujone (19.7–41.0%) and β-thujone (...

Research paper thumbnail of Synthesis and Study of 2 ‐ ( Pyrrolesulfonylmethyl ) ‐ N ‐ arylimines : A New Class of Inhibitors for Human Glutathione Transferase A 1 ‐ 1

Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthe... more Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthesis of 11 pyrrole derivatives as hGSTA1-1 inhibitors starting from 1-methyl-2-[(2-nitrobenzylsulfanyl]-1H-pyrrole. Molecular modeling revealed two locations in the enzyme H binding site: the catalytic primary one accommodating shorter and longer derivatives and the secondary one, where shorter derivatives can occupy. Derivative 9, displaying the highest inhibition and bearing a pnitroarylimino moiety, and derivative 4, lacking this moiety, were studied kinetically. Derivative 9 binds (Ki(9) = 71 ± 4 μM) at the primary site competitively vs CDNB. Derivative 4 binds (Ki(4) = 135 ± 27 μM) at the primary and secondary sites, allowing the binding of a second molecule (4 or CDNB) leading to formation of unreactive and reactive complexes, respectively. The arylmethylsulfonylpyrrole core structure is a new pharmacophore for hGSTA1-1, whereas its derivative 9 may serve as a lead structure.

Research paper thumbnail of Effect of acidic and enzymatic pretreatment on the analysis of mountain tea (Sideritis spp.) volatiles via distillation and ultrasound-assisted extraction

Journal of chromatography. A, Jan 17, 2017

A number of beneficial medicinal properties are attributed to the extract and essential oil of th... more A number of beneficial medicinal properties are attributed to the extract and essential oil of the aerial parts of Sideritis species (Lamiaceae). Hydrodistillation of the aerial parts of wild Sideritis clandestina ssp. peloponnesiaca (an endemic taxon in northern Peloponnesus, Greece) gave a low essential oil yield (<0.12%); about 65 components, mainly α-pinene, β-caryophyllene, β-pinene, globulol, caryophyllene oxide, were identified via GC-MS. Internal and external standards were used for quantification. For miniaturization of the procedure, we studied side-by-side maceration (MAC) and ultrasound-assisted extraction (UAE) methods, as well as the effect of preincubation in acidic medium (pH 4.8) for 75min at 37°C with or without a mixture of cellulase, hemicellulase and pectinase. Maceration and UAE provide consistent chemoprofiling of the main volatile compounds (about 20); UAE has lower demands on time, solvent, plant material (3g) and results in higher yields. Pretreatment wi...

Research paper thumbnail of Synthesis and Study of 2-(Pyrrolesulfonylmethyl)- N -arylimines: A New Class of Inhibitors for Human Glutathione Transferase A1-1

Journal of Medicinal Chemistry, 2012

Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthe... more Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthesis of 11 pyrrole derivatives as hGSTA1-1 inhibitors starting from 1-methyl-2-[(2-nitrobenzylsulfanyl]-1H-pyrrole. Molecular modeling revealed two locations in the enzyme H binding site: the catalytic primary one accommodating shorter and longer derivatives and the secondary one, where shorter derivatives can occupy. Derivative 9, displaying the highest inhibition and bearing a pnitroarylimino moiety, and derivative 4, lacking this moiety, were studied kinetically. Derivative 9 binds (K i(9) =7 1± 4 μM) at the primary site competitively vs CDNB. Derivative 4 binds (K i(4) = 135 ± 27 μM) at the primary and secondary sites, allowing the binding of a second molecule (4 or CDNB) leading to formation of unreactive and reactive complexes, respectively. The arylmethylsulfonylpyrrole core structure is a new pharmacophore for hGSTA1-1, whereas its derivative 9 may serve as a lead structure.

Research paper thumbnail of GC-MS and LC-DAD-MS Phytochemical Profiling for Characterization of Three Native Salvia Taxa from Eastern Mediterranean with Antiglycation Properties

Molecules

Salvia fruticosa and S. pomifera subsp. calycina are native to Eastern Mediterranean and S. pomif... more Salvia fruticosa and S. pomifera subsp. calycina are native to Eastern Mediterranean and S. pomifera subsp. pomifera is endemic to Greece. The primary aim of this study was to develop an analytical methodology for metabolomic profiling and to study their efficacy in combating glycation, the major biochemical complication of diabetes. After sequential ultrasound-assisted extraction of 2 g of leaves with petroleum ether and 70% methanol, the volatile metabolites in the petroleum ether extracts were studied with GC-MS (Gas Chromatography-Mass Spectrometry), whereas the polar metabolites in the hydroalcoholic extracts were determined and quantified by UHPLC-DAD–ESI-MS (Ultra-High Performance Liquid Chromatography–Diode Array Detector–Mass Spectrometry). This methodology was applied to five populations belonging to the three native taxa. 1,8-Cineole was the predominant volatile (34.8–39.0%) in S. fruticosa, while S. pomifera had a greater content of α-thujone (19.7–41.0%) and β-thujone (...

Research paper thumbnail of Synthesis and Study of 2 ‐ ( Pyrrolesulfonylmethyl ) ‐ N ‐ arylimines : A New Class of Inhibitors for Human Glutathione Transferase A 1 ‐ 1

Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthe... more Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthesis of 11 pyrrole derivatives as hGSTA1-1 inhibitors starting from 1-methyl-2-[(2-nitrobenzylsulfanyl]-1H-pyrrole. Molecular modeling revealed two locations in the enzyme H binding site: the catalytic primary one accommodating shorter and longer derivatives and the secondary one, where shorter derivatives can occupy. Derivative 9, displaying the highest inhibition and bearing a pnitroarylimino moiety, and derivative 4, lacking this moiety, were studied kinetically. Derivative 9 binds (Ki(9) = 71 ± 4 μM) at the primary site competitively vs CDNB. Derivative 4 binds (Ki(4) = 135 ± 27 μM) at the primary and secondary sites, allowing the binding of a second molecule (4 or CDNB) leading to formation of unreactive and reactive complexes, respectively. The arylmethylsulfonylpyrrole core structure is a new pharmacophore for hGSTA1-1, whereas its derivative 9 may serve as a lead structure.

Research paper thumbnail of Effect of acidic and enzymatic pretreatment on the analysis of mountain tea (Sideritis spp.) volatiles via distillation and ultrasound-assisted extraction

Journal of chromatography. A, Jan 17, 2017

A number of beneficial medicinal properties are attributed to the extract and essential oil of th... more A number of beneficial medicinal properties are attributed to the extract and essential oil of the aerial parts of Sideritis species (Lamiaceae). Hydrodistillation of the aerial parts of wild Sideritis clandestina ssp. peloponnesiaca (an endemic taxon in northern Peloponnesus, Greece) gave a low essential oil yield (<0.12%); about 65 components, mainly α-pinene, β-caryophyllene, β-pinene, globulol, caryophyllene oxide, were identified via GC-MS. Internal and external standards were used for quantification. For miniaturization of the procedure, we studied side-by-side maceration (MAC) and ultrasound-assisted extraction (UAE) methods, as well as the effect of preincubation in acidic medium (pH 4.8) for 75min at 37°C with or without a mixture of cellulase, hemicellulase and pectinase. Maceration and UAE provide consistent chemoprofiling of the main volatile compounds (about 20); UAE has lower demands on time, solvent, plant material (3g) and results in higher yields. Pretreatment wi...

Research paper thumbnail of Synthesis and Study of 2-(Pyrrolesulfonylmethyl)- N -arylimines: A New Class of Inhibitors for Human Glutathione Transferase A1-1

Journal of Medicinal Chemistry, 2012

Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthe... more Overexpression of human GSTA1-1 in tumor cells is part of MDR mechanisms. We report on the synthesis of 11 pyrrole derivatives as hGSTA1-1 inhibitors starting from 1-methyl-2-[(2-nitrobenzylsulfanyl]-1H-pyrrole. Molecular modeling revealed two locations in the enzyme H binding site: the catalytic primary one accommodating shorter and longer derivatives and the secondary one, where shorter derivatives can occupy. Derivative 9, displaying the highest inhibition and bearing a pnitroarylimino moiety, and derivative 4, lacking this moiety, were studied kinetically. Derivative 9 binds (K i(9) =7 1± 4 μM) at the primary site competitively vs CDNB. Derivative 4 binds (K i(4) = 135 ± 27 μM) at the primary and secondary sites, allowing the binding of a second molecule (4 or CDNB) leading to formation of unreactive and reactive complexes, respectively. The arylmethylsulfonylpyrrole core structure is a new pharmacophore for hGSTA1-1, whereas its derivative 9 may serve as a lead structure.