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Ulrike Lindequist - One of the best experts on this subject based on the ideXlab platform.
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inhibition of dna topoisomerase i by acylated triterpene saponins from Pittosporum angustifolium lodd
Natural Products and Bioprospecting, 2016Co-Authors: Christian Bäcker, Malgorzata N Drwal, Robert Preissner, Ulrike LindequistAbstract:Previous phytochemical investigation of the leaves and seeds of Pittosporum angustifolium Lodd. led to the isolation and structural elucidation of polyphenols and triterpene saponins. Evaluation for cytotoxicity of isolated saponins revealed that the predominant structural feature for a cytotoxic activity are acyl substituents at the oleanane aglycon backbone. The present work reports the results of a screening of 10 selected acylated saponins for their potential to inhibit the human DNA-topoisomerase I, giving rise to IC50 values in a range of 2.8-46.5 microM. To clarify the mode of observed cytotoxic action and, moreover, to distinguish from a pure surfactant effect which is commonly accompanied with saponins, these results indicate an involvement of the topoisomerase I and its role as a possible target structure for a cytotoxic activity. In addition, computational predictions of the fitting of saponins to the topoisomerase I-DNA complex, indicate a similar binding mode to that of clinically used topoisomerase I inhibitors. Ten acylated triterpene saponins from Pittosporum angustifolium were investigated for their potential to inhibit the human DNA-topoisomerase I and computational predictions of the fitting of saponins to the topoisomerase I-DNA complex were carried out.
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taraxastane type triterpene saponins isolated from Pittosporum angustifolium lodd
ChemInform, 2015Co-Authors: Christian Baecker, Kristina Jenettsiems, Karsten Siems, Timo H J Niedermeyer, Martina Wurster, Anja Bodtke, Ulrike LindequistAbstract:Two new taraxastane-type triterpene saponins, named pittangretoside L (I) and C1 (II), are isolated from the leaves of Pittosporum angustifolium.
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Taraxastane-type triterpene saponins isolated from Pittosporum angustifolium Lodd.
Zeitschrift für Naturforschung B, 2015Co-Authors: Christian Bäcker, Karsten Siems, Timo H J Niedermeyer, Martina Wurster, Anja Bodtke, Kristina Jenett-siems, Ulrike LindequistAbstract:AbstractTwo new taraxastane-type triterpene saponins, named pittangretosides L (1) and C1 (2), were isolated from the leaves of Pittosporum angustifolium Lodd. Their structures were established by NMR spectroscopic, mass spectrometric and chemical means. The in vitro cytotoxicity was evaluated against four cell lines. The compounds exhibited no cytotoxic activity up to a concentration of 130 μm.
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New Mono- and Bisdesmosidic Triterpene Glycosides from Pittosporum angustifolium Lodd
Zeitschrift für Naturforschung B, 2014Co-Authors: Christian Bäcker, Karsten Siems, Timo H J Niedermeyer, Martina Wurster, Anja Bodtke, Kristina Jenett-siems, Ulrike LindequistAbstract:Abstract Fifteen new mono- and bisdesmosidic triterpene saponins, named pittangretosides J, K, M, Q- Z, A1, and B1, along with three known compounds were isolated from the leaves of Pittosporum angustifolium. By spectroscopic, mass spectrometric and chemical evidence, their structures were established as glycosides of A1- and R1-barrigenol, barringtogenol C and camelliagenin A backbones
Giacomo Dugo - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of cd ii cu ii pb ii and zn ii by derivative stripping chronopotentiometry in Pittosporum tobira leaves a measurement of local atmospheric pollution in messina sicily italy
Chemosphere, 2005Co-Authors: Rosina Matarese Palmieri, Giuseppa Di Bella, Lara La Pera, Giacomo DugoAbstract:The purpose of this study is to investigate the bio-accumulation of Cd(II), Cu(II), Pb(II) and Zn(II) in Pittosporum tobira (Thunb.) Aiton leaves sampled in different zones of Messina, in order to assess the level of atmospheric metal deposition in correlation with the traffic volume. Derivative stripping chronopotentiometry was used as a practical, precise and sensitive technique to determine simultaneously Cd, Cu, Pb and Zn levels in Pittosporum leaves. In the optimised electro-chemical conditions, detection limits lower than 0.05 μg kg -1 were achieved, whereas the accuracy, expressed as obtained recoveries from certified materials, was in the range 93.5-102.7%. The obtained data provided evidence that Cd and Pb levels significantly decreased from high to low traffic density zones (p < 0.005, ANOVA), whereas Cu and Zn are accumulated by plants particularly from the soil and their contents is not related to the traffic volume.
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simultaneous determination of cd ii cu ii pb ii and zn ii by derivative stripping chronopotentiometry in Pittosporum tobira leaves a measurement of local atmospheric pollution in messina sicily italy
Chemosphere, 2005Co-Authors: Rosina Matarese Palmieri, Giuseppa Di Bella, Lara La Pera, Giacomo DugoAbstract:Abstract The purpose of this study is to investigate the bio-accumulation of Cd(II), Cu(II), Pb(II) and Zn(II) in Pittosporum tobira (Thunb.) Aiton leaves sampled in different zones of Messina, in order to assess the level of atmospheric metal deposition in correlation with the traffic volume. Derivative stripping chronopotentiometry was used as a practical, precise and sensitive technique to determine simultaneously Cd, Cu, Pb and Zn levels in Pittosporum leaves. In the optimised electro-chemical conditions, detection limits lower than 0.05 μg kg−1 were achieved, whereas the accuracy, expressed as obtained recoveries from certified materials, was in the range 93.5–102.7%. The obtained data provided evidence that Cd and Pb levels significantly decreased from high to low traffic density zones (p
Raffaele Riccio - One of the best experts on this subject based on the ideXlab platform.
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isolation and structure elucidation of four new triterpenoid estersaponins from fruits of Pittosporum tobira ait
Tetrahedron, 2002Co-Authors: Ilaria Dacquarica, Maria Cristina Di Giovanni, Francesco Gasparrini, D Misiti, Claudio Darrigo, Nicolina Fagnano, Decimo Guarnieri, Giovanni Iacono, Giuseppe Bifulco, Raffaele RiccioAbstract:Abstract Four new triterpenoid estersaponins, tentatively designated as IIIA2 ( 1 ), IIIA3 ( 2 ), IIIB2 ( 3 ), and IIIC4 ( 4 ) have been isolated from fruits of Pittosporum tobira ait . and their structures elucidated by spectroscopic and chemical analyses. All the four compounds consist of an acylated pentacyclic triterpenoid aglycone which bears the same oligosaccharide portion. The crude saponin mixture (CIDI) was found to show significant in vitro and in vivo cytotoxicity in different human cancer cell lines.
Rosina Matarese Palmieri - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of cd ii cu ii pb ii and zn ii by derivative stripping chronopotentiometry in Pittosporum tobira leaves a measurement of local atmospheric pollution in messina sicily italy
Chemosphere, 2005Co-Authors: Rosina Matarese Palmieri, Giuseppa Di Bella, Lara La Pera, Giacomo DugoAbstract:The purpose of this study is to investigate the bio-accumulation of Cd(II), Cu(II), Pb(II) and Zn(II) in Pittosporum tobira (Thunb.) Aiton leaves sampled in different zones of Messina, in order to assess the level of atmospheric metal deposition in correlation with the traffic volume. Derivative stripping chronopotentiometry was used as a practical, precise and sensitive technique to determine simultaneously Cd, Cu, Pb and Zn levels in Pittosporum leaves. In the optimised electro-chemical conditions, detection limits lower than 0.05 μg kg -1 were achieved, whereas the accuracy, expressed as obtained recoveries from certified materials, was in the range 93.5-102.7%. The obtained data provided evidence that Cd and Pb levels significantly decreased from high to low traffic density zones (p < 0.005, ANOVA), whereas Cu and Zn are accumulated by plants particularly from the soil and their contents is not related to the traffic volume.
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simultaneous determination of cd ii cu ii pb ii and zn ii by derivative stripping chronopotentiometry in Pittosporum tobira leaves a measurement of local atmospheric pollution in messina sicily italy
Chemosphere, 2005Co-Authors: Rosina Matarese Palmieri, Giuseppa Di Bella, Lara La Pera, Giacomo DugoAbstract:Abstract The purpose of this study is to investigate the bio-accumulation of Cd(II), Cu(II), Pb(II) and Zn(II) in Pittosporum tobira (Thunb.) Aiton leaves sampled in different zones of Messina, in order to assess the level of atmospheric metal deposition in correlation with the traffic volume. Derivative stripping chronopotentiometry was used as a practical, precise and sensitive technique to determine simultaneously Cd, Cu, Pb and Zn levels in Pittosporum leaves. In the optimised electro-chemical conditions, detection limits lower than 0.05 μg kg−1 were achieved, whereas the accuracy, expressed as obtained recoveries from certified materials, was in the range 93.5–102.7%. The obtained data provided evidence that Cd and Pb levels significantly decreased from high to low traffic density zones (p
Ilaria Dacquarica - One of the best experts on this subject based on the ideXlab platform.
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isolation and structure elucidation of four new triterpenoid estersaponins from fruits of Pittosporum tobira ait
Tetrahedron, 2002Co-Authors: Ilaria Dacquarica, Maria Cristina Di Giovanni, Francesco Gasparrini, D Misiti, Claudio Darrigo, Nicolina Fagnano, Decimo Guarnieri, Giovanni Iacono, Giuseppe Bifulco, Raffaele RiccioAbstract:Abstract Four new triterpenoid estersaponins, tentatively designated as IIIA2 ( 1 ), IIIA3 ( 2 ), IIIB2 ( 3 ), and IIIC4 ( 4 ) have been isolated from fruits of Pittosporum tobira ait . and their structures elucidated by spectroscopic and chemical analyses. All the four compounds consist of an acylated pentacyclic triterpenoid aglycone which bears the same oligosaccharide portion. The crude saponin mixture (CIDI) was found to show significant in vitro and in vivo cytotoxicity in different human cancer cell lines.