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Paride Papadia
Ruolo
Ricercatore
Organizzazione
Università del Salento
Dipartimento
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali
Area Scientifica
Area 03 - Scienze chimiche
Settore Scientifico Disciplinare
CHIM/03 - Chimica Generale e Inorganica
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
In invertebrate biomonitors of chemical pollution, emphasis has been generally given to mean accumulation patterns and how they reflect varying environmental levels of contamination. Intra-population variability, and how it relates with individual phenotypic traits, has received less attention. Here, a set of analytes including trace elements (B, Ba, Cd, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sr, V, and Zn), macroelements (C, Ca, K, Mg, N, Na), and carbon and nitrogen stable isotopes (δ13C and δ15N) was measured in two populations of the crayfish Procambarus clarkii fromLake Trasimeno and Lake Bolsena (Central Italy). The influence of location, sex, body size, and condition factor was assessed; in addition, the analyte correlation profiles of the two populations were compared to verify their congruence. In general, significant inter-lake differences were observed in the concentration of both trace- and macroelements in crayfish tissues, generally mirroring the local chemistry of water and of benthic non-living matrices (sediment and plant detritus). Crayfish CN isotopic signatures excluded the occurrence of inter-lake variations in their omnivorous trophic habits. Correlation profiles varied considerably between the two populations in the nature and strength of bivariate relationships. However, Mantel tests and procrustean analyses indicated a general, significant congruence; C, N, and, to a lesser extent K, Li, Ni, Pb, and δ13C showed the highest procrustean residuals, suggesting that their associations with other analytes may be partially influenced by inter-population differences in growing phases. Our study indicates that the local geochemistry of the lacustrine environment influences the elemental fingerprint of Procambarus clarkii; the considerable inter-individual variability in the concentration of analytes, however, does not significantly reflect on their association, thus corroborating its effectiveness as an indicator species.
Aim of this study was to determine the content of bioactive phytochemicals in Capparis spinosa subsp. rupestris (syn. C. orientalis), a less investigated species of caper and compare the chemical profile of this species with that of other studied Capparis sp. and especially with the related cultigen C. spinosa subsp. spinosa. Chemical composition of seed oil and glucosinolates, as well as of glucosinolates and flavonoids from the aerial parts of the plant have been determined and data reported here. Oil from the plant seeds is rich in unsaturated and rare lipids such as cis-vaccenic acid; the main glucosinolate is glucocapperin. The aerial parts are characterized by rutin as the dominant flavonoid. The overall phytochemical data obtained from the analysis of C. spinosa subsp. rupestris indicate that this species represents a very rich source of bioactive compounds of nutraceutical relevance although the compositional profile does not differentiate this subspecies from C. spinosa subsp. spinosa.
The immediate visual comparison of platinum chemotherapeutics' effects in eukaryotic cells using accessible plant models of transgenic Arabidopsis thaliana is reported. The leading anticancer drug cisplatin, a third generation drug used for colon cancer, oxaliplatin and kiteplatin, promising Pt-based anticancer drugs effective against resistant lines, were administered to transgenic A. thaliana plants monitoring their effects on cells from different tissues. The transgenic plants' cell cytoskeletons were labelled by the green fluorescent protein (GFP)-tagged microtubule-protein TUA6 (TUA6-GFP), while the vacuolar organization was evidenced by two soluble chimerical GFPs (GFPChi and AleuGFP) and one transmembrane GFP-tagged tonoplast intrinsic protein 1-1 (TIP1.1-GFP). The three drugs showed easily recognizable effects on plant subcellular organization, thereby providing evidence for a differentiated drug targeting. Genetically modified A. thaliana are confirmed as a possible rapid and low-cost screening tool for better understanding the mechanism of action of human anticancer drugs.
The reaction of the potential anticancer drug kiteplatin, cis-[PtCl2(cis-1,4-DACH)], with oligomers of single- and double-stranded DNA ranging from 2 to 12 base pairs in length was performed as a model for DNA interaction. The potential for conformational flexibility of single-stranded adducts was examined with density functional theory (DFT) and compared with data from 1H-NMR 1D and 2D spectroscopy. This indicates the presence of multiple conformations of an adduct with d(GpG), but only one form of the adduct with d(TGGT). The importance of a suitable theoretical model, and in particular basis set, in reproducing experimental data is demonstrated. The DFT theoretical model was extended to platinated base pair step (GG/CC), allowing a comparison to the related compounds cisplatin and oxaliplatin. Adducts of kiteplatin with larger fragments of double-stranded DNA, including tetramer, octamer, and dodecamer, were studied theoretically using hybrid quantum mechanics/molecular mechanics methods. Structural parameters of all the base-paired models were evaluated and binding energies calculated in gas phase and in solution; these are compared across the series and also with the related complexes cisplatin and oxaliplatin, thus revealing insights into how kiteplatin binds to DNA and similarities and differences between this and related compounds. Graphical Abstract: [Figure not available: see fulltext.]
The anticancer activity of cisplatin is triggered by its formation of intrastrand adducts involving adjacent G residues of DNA. To obtain information on the different conformers that can be formed{,} carrier ligands such as 2{,}2[prime or minute]-bipiperidine{,} which provide large steric bulk near the platinum coordination plane and decrease the dynamic motion about the Pt-N7 bonds{,} were introduced ({"}retro-modelling{"} approach). In the present study we investigate the effect of cis-1{,}4-diaminocyclohexane (cis-1{,}4-DACH) on the formation{,} stability{,} and stereochemistry of (cis-1{,}4-DACH)Pt(ss-oligo) adducts (ss-oligo = d(GpG) with 3[prime or minute]- and/or 5[prime or minute]-substituents). Interesting features of this ligand{,} absent in previous retro-modelling studies{,} include the large bite angle (expected to impede the ease of interconversion between possible conformers){,} the presence of two protons on each nitrogen (a characteristic associated with antitumor activity){,} and the absence of chiral centres. The use of cis-1{,}4-DACH has made it possible to detect different conformers in a system containing a primary diamine carrier ligand associated with anticancer activity and to confirm the previous hypothesis that the coexistence of different conformers established in studies of retro models having relatively bulky ligands is not an artefact resulting from carrier-ligand bulk. Moreover{,} the data for the (cis-1{,}4-DACH)Pt(d(GpG)) and (cis-1{,}4-DACH)Pt(d(GGTTT)) adducts indicate that at a temperature close to the physiological one (40 [degree]C) HH1 and [capital Delta]HT1 conformers are present in comparable amounts. In contrast{,} at low temperature (close to 0 [degree]C) the equilibrium shifts dramatically toward the more stable HH1 conformer (for the (cis-1{,}4-DACH)Pt(d(TGGT)) adduct the HH1 conformer is always dominant{,} even at high temperature). Notably{,} (cis-1{,}4-DACH)PtCl2 (Kiteplatin) has been recently reinvestigated and found to be particularly active against colorectal cancer (including oxaliplatin-resistant phenotypes).
Artemisia annua tea has been proven to be a very effective treatment for malaria in various clinical trials, but to date its efficacy has not been investigated in vitro. A study was therefore performed to evaluate the effects of A. annua tea on Plasmodium falciparum cultures in vitro. The concentration of artemisinin in the herbal tea preparation was also determined. The herbal tea extract was tested against chloroquine (CQ)-sensitive D10 and CQ-resistant W2 strains of P. falciparum using the parasite lactate dehydrogenase assay. Quantification of artemisinin in the extract of leaves of A. annua was performed using proton nuclear magnetic resonance (1H-NMR). Results of the in vitro tests were consistent with the clinical efficacy of A. annua tea [50% inhibitory concentration (IC50) for strain D10=1.11±0.21μg/ml; IC50 for strain W2=0.88±0.35μg/ml]. The concentration of artemisinin in A. annua tea (0.18±0.02% of dry weight) was far too low to be responsible for the antimalarial activity. The artemisinin present in the tea is probably co-solubilised with other ingredients, some of which also have antimalarial activity and act synergistically with it. These compounds also merit further research to determine whether their presence hinders the development of parasite resistance compared with pure artemisinin.
An inverse linear relationship between the experimentally observed (195)Pt NMR signals and the overall sum of coordinated halido ligands' ionic radii was discovered in Pt(ii) and Pt(iv) complexes. The reduction of (195)Pt NMR frequencies parallels the increase of coordinated halido ligands' ionic radii sum. This suggests that each halido ligand may act as a conducting ring whose induced electric current shields the (195)Pt NMR signals proportionally to the ionic radius of the coordinated halido ligand.
Nine hundred extra virgin olive oils (EVOO) were extracted from individual olive trees of four olive cultivars (Coratina, Cima di Mola, Ogliarola, Peranzana), originating from the provinces of Bari and Foggia (Apulia region, Southern Italy) and collected during two consecutive harvesting seasons (2013/14 and 2014/15). Following genetic identification of individual olive trees, a detailed Apulian EVOO NMR database was built using 900 oils samples obtained from 900 cultivar certified single trees. A study on the olive oil lipid profile was carried out by statistical multivariate analysis (Principal Component Analysis, PCA, Partial Least-Squares Discriminant Analysis, PLS-DA, Orthogonal Partial Least-Squares Discriminant Analysis, OPLS-DA). Influence of cultivar and weather conditions, such as the summer rainfall, on the oil metabolic profile have been evaluated. Mahalanobis distances and J2 criterion have been measured to assess the quality of resulting scores clusters for each cultivar in the two harvesting campaigns. The four studied cultivars showed non homogeneous behavior. Notwithstanding the geographical spread and the wide number of samples, Coratina showed a consistent behavior of its metabolic profile in the two considered harvests. Among the other three Peranzana showed the second more consistent behavior, while Cima di Mola and Ogliarola having the biggest change over the two years.
The reactivity with acetylene of [PtX2(Me2phen)] (X = Cl, Br, I) complexes has been investigated. Whereas the chlorido species [PtCl2(Me2phen)] exhibits negligible reactivity at short reaction times, the bromido and iodido species [PtBr2(Me2phen)] and [PtI2(Me2phen)] lead initially to formation of Pt(II) five-coordinate complexes, [PtX2(η2-CHuCH)(Me2phen)], that evolve to four-coordinate alkenyl complexes of the type [PtX(η1 -E-CHvCHX)(Me2phen)]. The alkenyl complexes, in the presence of excess acetylene, establish an equilibrium with the five-coordinate alkyne–alkenyl species [PtX(η1-E-CHvCHX)(η2-CHuCH)(Me2phen)] (X = Br, I). The π-bonded acetylene can be exchanged with free olefins or CuO, affording the new alkene–alkenyl or carbonyl–alkenyl complexes [PtX(η1-E-CHvCHX)(η2-olefin)(Me2phen)] and [PtX(η1-E-CHvCHX)(CuO)(Me2phen)]. The five-coordinate geometry of the alkyne–alkenyl and alkene–alkenyl complexes was assessed from NMR data and is fully consistent with that of a previously determined X-ray structure of [PtBr(η1-E-CHvCHBr)(η2-CH2vCH2)(Me2phen)].
Mono-varietal extra virgin olive oils were micro-extracted from drupes that were selectively collected from 28 trees distributed in five different Southern Italian Apulian areas. Nuclear Magnetic Resonance (NMR) profiles of these oil samples were correlated to the genetic (young green material) and soil (samples collected within the foliage projection) data of the tree of origin. Genetic analysis, performed on the samples using SSRs (Simple Sequence Repeats) by 9 microsatellite loci, confirmed the specific cultivar assignment (among Cima di Mola, Coratina, Ogliarola, and Oliva Rossa cultivars). Chemometric methods applied to 1H-NMR spectroscopic data were used for cultivar and geographical origin discrimination of the studied extra virgin olive oils. Linear Discriminant Analysis (LDA) afforded a high reliability degree for discriminating cultivars (almost 90% of prediction ability), and a good assigning ability for the geographical origin (Ogliarola and Coratina samples used as subsets). Soil analyses were performed for each tree. Regression analysis was applied to soil composition in order to correlate available nutrients and total metals with the content of fatty acids and minor components present in monovarietal extra virgin olive oils. In the case of oleic and linoleic fatty acids, and for some terpenes, B, Cr, Mn, Zn were found to give significant correlations. Zn and Mn were the most significant trace elements for all the correlations found (p < 0.01). The results obtained (genetic, spectroscopic and soil analyses) are discussed as a multidisciplinary approach for setting up a strategy for a cultivar and/or geographic origin certification committed database construction.
Carbohydrate polimeric microcapsules were assembled using a LbL approach onto a CaCO3 core. The microcapsules were used to delivery the anticancer drug cisplatin into HeLa and MCF-7 cancer cell lines. Drug encapsulation, measured by ICP spectroscopy, was around 50% of the charging solution. Fluorimetric measurements showed an efficient cellular uptake of polysacchardic microcapsules in both cell lines. The drug-loaded capsules demonstrated a better efficiency against cell viability than the free drug. Specifically, the amount of platinum reaching genomic DNA was measured, showing that encapsulation improves the nuclear delivery of the drug for both cell lines.
A simple synthesis was applied and tested for the preparation of boron-doped titanium dioxide [TiO2(B)] nanocrystals using titanium tetraisopropoxide (TTIP) together with boric acid (H3BO3) and benzyl alcohol as reaction solvent. Changes in the TTIP/H3BO3 molar ratio allowed a scalable synthetic protocol with a significant B-dopant control. In particular, this approach does not need surfactants or a final calcination step. X-ray diffractometry (XRD), low- and high-resolution transmission electron microscopy (TEM and HRTEM), and micro Raman spectroscopy revealed that the TiO2 nanocrystals produced have diameters up to about 10 nm and are mainly of the anatase phase but that a brookite phase was progressively formed with increased dopant level. The amount of boron was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the presence of boron inside the crystals was determined by 11B cross-polarized magic-angle spinning nuclear magnetic resonance (11B CP-MAS NMR) spectroscopy. X-ray photoelectron spectroscopy (XPS) revealed the presence of boron on the nanocrystal surfaces, confirming the trend in the dopant concentration already observed with ICP-AES elemental analysis. Microphotoluminescence studies indicated the formation of three different typical luminescent defect states in correlation with the amount of added boron in the titania. UV/Vis absorption spectra showed a boron-dependent redshift of the absorption edge.
Strategies to control diffusion of malaria needs to account for the increase of resistance of the parasite to the conventional antimalarial drugs. It has been proposed that a traditional aqueous preparation from Artemisia annua, with a low content of the active compound, artemisinin, may reduce the risk of resistance of the protozoa and be relatively more effective in the treatment of the disease. The solubility properties of the molecule have been the matter of concern about the therapeutic usefulness of herbal teas from A. annua. The present study aimed at analysing the chemical profile of a tea infusion from A. annua. Tea from A. annua was prepared through infusion of the plant aerial parts in water for 1, 24 and 48 h. Content of artemisinin was determined by HPLC-ELSD. Overall chemical characterization of the extracts was carried out by a combination of metabolomic techniques. The artemisinin content varied only slightly in the three different extracts (about 0.12%). A series of mono-caffeoyl- and mono-feruloyl-quinic acids, di-caffeoyl- and di-feruloyl-quinic acids was identified as main components of the tea infusion, together with some flavonoids. Reconstitution of the same extracts in less polar or apolar solvents resulted in a different composition with no phenolics and a much lower concentration of artemisinin.
A. annua was usually used to prepare a tea and if it contains effective amounts of artemisinin, it might be used today as a self-reliant treatment of malaria [1]. Artemisia annua tea has proven itself to be a very effective treatment for malaria in various clinical trials, but to date, his efficacy has not been investigated in vitro. Therefore, we have carried out a study for the evaluation of effects of A. annua tea on Plasmodium falciparum cultures in vitro. We also determined the concentration of artemisinin in herbal tea preparation. The compound was tested against chloroquine-sensitive D10 and chloroquine-resistant W2 strains of P. falciparum using the parasite lactate dehydrogenase assay [2]. The quantification of artemisinin in the extract of leaves of A. annua was obtained using an 1H NMR method. The in vitro tests conducted in this study confirm the clinical efficacy demonstrated by the tea of A. annua in vivo on both chloroquine-sensitive D10 and chloroquine-resistant W2 strains. The concentration of artemisinin in A. annua tea is lower with respect to that of pure artemisinin responsible for the same antimalarial activity. The artemisinin present in the tea is probably co-solubilised with other ingredients, some of which may also have antimalarial activity and act synergistically with it. The presence of other active ingredients suggests that A. annua is a natural artemisinin combination therapy. These compounds also merit further research, to see whether their presence hinders the development of parasite resistance compared to pure artemisinin [3]. [1] C.H.Blanke, G.B.Naisabha, M.B.Balema, G.M.Mbaruku, L.Heide and M.S.Muller, Trop. Doct., 38, 2008, 113–6. [2] M.T.Makler, J.M.Ries, J.A.Williams, J.E.Bamcroft, R.C.Piper, B.L.Gibbins, et al, Am.J.Trop.Med.Hyg., 48(6), 1993, 739-41. [3] Work supported by Regione Puglia Progetto Strategico PS70.
A smart nanocarrier system for cancer therapy, based on a recently developed technique for preparing pure nanometric calcium carbonate (CaCO3), was studied. Different approaches were used to obtain sustained release of cisplatin: at first, pure CaCO3 nanoparticles were evaluated as carriers, then the nanoparticles were functionalized with polymer or silanes, and finally they were employed as a substrate to build layer by layer (LbL) self-assembled polyelectrolyte nanocapsules. Loading efficiency and release kinetics were measured. The best loadings were obtained with the LbL nanocapsules, allowing for high loading efficiency and the possibility of controlling the release rate of the drug. The behavior of all the carriers was evaluated on four neoplastic cell lines, representative of different types of neoplastic disease, namely MCF-7 (breast cancer), SKOV-3 (ovarian cancer), HeLa (cervical cancer) and CACO-2 (human epithelial colorectal adenocarcinoma). Negligible cytotoxicity of the nanoparticles, functionalized nanoparticles, and nanocapsules was observed in experiments with all cell lines. Nanocapsules were functionalized with fluorescein isothiocyanate (FITC) in order to track their kinetic of internalization and localization in the cell line by confocal laser scanning microscopy (CLSM). The cytotoxicity of the loaded capsules was evaluated, showing cell survival rates close to those expected for non-encapsulated cisplatin at the same nominal concentration.
AbstractBackground Selective imaging of lysosomes by fluorescence microscopy using specific fluorescent probes allows the study of biological processes and it is potentially useful also for diagnosis. Lysosomes are involved in numerous physiological processes, such as bone and tissue remodeling, plasma membrane repair, and cholesterol homeostasis, along with cell death and cell signaling. Despite the great number of dyes available today on the market, the search for new fluorescent dyes easily up-taken by cells, biocompatible and bearing bright and long-lasting fluorescence is still a priority. Methods Two thiophene-based fluorescent dyes, {TC1} and TC2, were synthetized as lysosome-specific probes. Results The new dyes showed high selectivity for fluorescent staining and imaging of lysosomes and disclosed high photostability, low toxicity and pH insensitivity in the range 2–10. Conclusions The {TC} dyes exhibited high co-localization coefficients (> 95%) and moderate quantum yields. They showed high biocompatibility and long-term retention, important features for biological applications. General significance The results of the present work disclose a new class of organic dyes with potential wide applications as specific and efficient lysosome probes in the study of various biological processes.
Abstract The single crystal X-ray structure of the pentacoordinate complex [PtBr2(η2-CH2double bond; length as m-dashCH2)(Me2phen)], Me2phen = 2,9-dimethyl-1,10-phenanthroline, is here reported for the first time. Comparison of the complete series of [PtX2(η2-CH2double bond; length as m-dashCH2)(Me2phen)] (X = Cl, Br, I) X-ray structures shows a very low variability of the bond lengths and angles, in the trigonal equatorial plane (where η2-olefin and Me2phen are bound), on varying the coordinated axial halogens. In first approximation, this suggests describing as independents and not interacting the two subsystems constituted by the metal bonds with axial (X–Pt–X) and equatorial ligands (Me2phen–Pt–η2-ethene). This means that the electric charge donated to the metal, by the axial ligands, cannot substantially modify the bonds of the metal with the ligands in the trigonal equatorial plane. The 1H, 13C, 15N and 195Pt NMR chemical shifts variations, studied as a function of the ionic radius of the axial halides are here discussed. The NMR data strongly suggest the existence of electric pseudo-ring currents circulating around the Pt–X axes and modulated by the ionic radius of the coordinated halides.
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