Publications by authors named "Paride Papadia"

22 Publications

  • Page 1 of 1

Aquatic Mosses as Adaptable Bio-Filters for Heavy Metal Removal from Contaminated Water.

Int J Mol Sci 2020 Jul 5;21(13). Epub 2020 Jul 5.

DISTEBA (Department of Biological and Environmental Sciences and Technologies), University of Salento, Campus ECOTEKNE, 73100 Lecce, Italy.

Heavy metals (HMs) are released into the environment by many human activities and persist in water even after remediation. The efficient filtration of solubilized HMs is extremely difficult. Phytoremediation appears a convenient tool to remove HMs from polluted water, but it is limited by the choice of plants able to adapt to filtration of polluted water in terms of space and physiological needs. Biomasses are often preferred. Aquatic moss biomasses, thanks to gametophyte characteristics, can act as live filtering material. The potential for phytoremediation of Hypnales aquatic mosses has been poorly investigated compared to aquatic macrophytes. Their potential is usually indicated as a tool for bioindication and environmental monitoring more than for pollutant removal. When phytoremediation has been considered, insufficient attention has been paid to the adaptability of biomasses to different needs. In this study the heavy metal uptake of moss grown in two different light conditions, was tested with high concentrations of elements such as Pb, Cd, Zn, Cu, As, and Cr. This moss produces dense mats with few culture needs. The experimental design confirmed the capacity of the moss to accumulate HMs accordingly to their physiology and then demonstrated that a significant proportion of HMs was accumulated within a few hours. In addition to the biosorption effect, an evident contribution of the active simplistic mass can be evidenced. These reports of HM accumulation within short time intervals, show how this moss is particularly suitable as an adaptable bio-filter, representing a new opportunity for water eco-sustainable remediation.
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http://dx.doi.org/10.3390/ijms21134769DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7369764PMC
July 2020

Platinum(IV) Complexes of -1,2-diamino-4-cyclohexene: Prodrugs Affording an Oxaliplatin Analogue that Overcomes Cancer Resistance.

Int J Mol Sci 2020 Mar 27;21(7). Epub 2020 Mar 27.

Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via E. Orabona 4, 70125 Bari, Italy.

Six platinum(IV) compounds derived from an oxaliplatin analogue containing the unsaturated cyclic diamine -1,2-diamino-4-cyclohexene (DACHEX), in place of the 1,2-diaminocyclohexane, and a range of axial ligands, were synthesized and characterized. The derivatives with at least one axial chlorido ligand demonstrated solvent-assisted photoreduction. The electrochemical redox behavior was investigated by cyclic voltammetry; all compounds showed reduction potentials suitable for activation in vivo. X-ray photoelectron spectroscopy (XPS) data indicated an X-ray-induced surface reduction of the Pt(IV) substrates, which correlates with the reduction potentials measured by cyclic voltammetry. The cytotoxic activity was assessed in vitro on a panel of human cancer cell lines, also including oxaliplatin-resistant cancer cells, and compared with that of the reference compounds cisplatin and oxaliplatin; all IC values were remarkably lower than those elicited by cisplatin and somewhat lower than those of oxaliplatin. Compared to the other Pt(IV) compounds of the series, the bis-benzoate derivative was by far (5-8 times) the most cytotoxic showing that low reduction potential and high lipophilicity are essential for good cytotoxicity. Interestingly, all the complexes proved to be more active than cisplatin and oxaliplatin even in three-dimensional spheroids of A431 human cervical cancer cells.
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http://dx.doi.org/10.3390/ijms21072325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7177638PMC
March 2020

CaCO as an Environmentally Friendly Renewable Material for Drug Delivery Systems: Uptake of HSA-CaCO Nanocrystals Conjugates in Cancer Cell Lines.

Materials (Basel) 2019 May 7;12(9). Epub 2019 May 7.

Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università del Salento & UdR INSTM di Lecce, Campus Universitario, Via Monteroni, 73100 Lecce, Italy.

Chemical and biochemical functionalization of nanoparticles (NPs) can lead to an active cellular uptake enhancing their efficacy thanks to the targeted localization in tumors. In the present study calcium carbonate nano-crystals (CCNs), stabilized by an alcohol dehydration method, were successfully modified by grafting human serum albumin (HSA) on the surface to obtain a pure protein corona. Two types of CCNs were used: naked CaCO and the (3-aminopropyl)triethoxysilane (APTES) modified CaCO-NH. The HSA conjugation with naked CCN and amino-functionalized CCN (CCN-NH) was established through the investigation of modification in size, zeta potential, and morphology by Transmission Electron Microscopy (TEM). The amount of HSA coating on the CCNs surface was assessed by spectrophotometry. Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) confirmed the grafting of APTES to the surface and successive adsorption of HSA. Furthermore, to evaluate the effect of protein complexation of CCNs on cellular behavior, bioavailability, and biological responses, three human model cancer cell lines, breast cancer (MCF7), cervical cancer (HeLa), and colon carcinoma (Caco-2) were selected to characterize the internalization kinetics, localization, and bio-interaction of the protein-enclosed CCNs. To monitor internalization of the various conjugates, chemical modification with fluorescein-isothiocyanate (FITC) was performed, and their stability over time was measured. Confocal microscopy was used to probe the uptake and confirm localization in the perinuclear region of the cancer cells. Flow cytometry assays confirmed that the bio-functionalization influence cellular uptake and the CCNs behavior depends on both cell line and surface features.
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http://dx.doi.org/10.3390/ma12091481DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6539763PMC
May 2019

Variation in Membrane Trafficking Linked to SNARE AtSYP51 Interaction With Aquaporin NIP1;1.

Front Plant Sci 2018 9;9:1949. Epub 2019 Jan 9.

Laboratory of Botany, DISTEBA (Diartimento di Scienze e Tecnologie Biologiche e Ambientali), University of Salento, Lecce, Italy.

SYP51 and 52 are the two members of the SYP5 Qc-SNARE gene family in . These two proteins, besides their high level of sequence identity (85%), have shown to have differential functional specificity and possess a different interactome. Here we describe a unique and specific interaction of SYP51 with an ER aquaporin, AtNIP1;1 (also known as NLM1) indicated to be able to transport arsenite [As(III)] and previously localized on PM. In the present work we investigate in detail such localization and characterize the interaction with SYP51. We suggest that this interaction may reveal a new mechanism regulating tonoplast invagination and recycling. We propose this interaction to be part of a regulatory mechanism associated with direct membrane transport from ER to tonoplast and Golgi mediated vesicle trafficking. We also demonstrate that NIP1;1 is important for plant tolerance to arsenite but does not alter its uptake or translocation. To explain such phenomenon the hypothesis that SYP51/NIP1;1 interaction modifies ER and vacuole ability to accumulate arsenite is discussed.
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http://dx.doi.org/10.3389/fpls.2018.01949DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334215PMC
January 2019

Beyond the mean: A comparison of trace- and macroelement correlation profiles of two lacustrine populations of the crayfish Procambarus clarkii.

Sci Total Environ 2018 May 27;624:1455-1466. Epub 2017 Dec 27.

CoNISMa, Consorzio Nazionale Interuniversitario per le Scienze del Mare, 00196 Roma, Italy; Department of Earth and Marine Sciences, University of Palermo, 90123 Palermo, Italy.

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 (δC and δN) was measured in two populations of the crayfish Procambarus clarkii from Lake 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 δC 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.
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http://dx.doi.org/10.1016/j.scitotenv.2017.12.106DOI Listing
May 2018

Nanostructured polysaccharidic microcapsules for intracellular release of cisplatin.

Int J Biol Macromol 2017 Jun 20;99:187-195. Epub 2017 Feb 20.

Biological and Environmental Sciences and Technology Department, University of Salento, & UdR INSTM di Lecce-Campus Universitario, via Monteroni, 73100 Lecce, Italy; Istituto di Nanotecnologia (CNR-NANOTEC) University of Salento, Via Monteroni, 73100 Lecce, Italy. Electronic address:

Carbohydrate polimeric microcapsules were assembled using a LbL approach onto a CaCO 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.
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http://dx.doi.org/10.1016/j.ijbiomac.2017.02.066DOI Listing
June 2017

Cisplatin, Oxaliplatin, and Kiteplatin Subcellular Effects Compared in a Plant Model.

Int J Mol Sci 2017 Jan 31;18(2). Epub 2017 Jan 31.

Department of Biotechnology and Environmental Sciences, University of Salento, via Monteroni-Centro Ecotekne, 73100 Lecce, Italy.

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.
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http://dx.doi.org/10.3390/ijms18020306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5343842PMC
January 2017

Harvest year effects on Apulian EVOOs evaluated by H NMR based metabolomics.

PeerJ 2016 15;4:e2740. Epub 2016 Dec 15.

University of Salento, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Lecce, Italy.

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 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.
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http://dx.doi.org/10.7717/peerj.2740DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5162422PMC
December 2016

Synthesis of biocompatible polymeric nano-capsules based on calcium carbonate: A potential cisplatin delivery system.

J Inorg Biochem 2015 Dec 1;153:284-292. Epub 2015 Nov 1.

CNR NANOTEC-Istituto di Nanotecnologia - CNR, Via Monteroni, 73100 Lecce, Italy; Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, 73100 Lecce, Italy. Electronic address:

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http://dx.doi.org/10.1016/j.jinorgbio.2015.10.014DOI Listing
December 2015

Thiophene-based fluorescent probes with low cytotoxicity and high photostability for lysosomes in living cells.

Biochim Biophys Acta 2015 Feb 23;1850(2):385-92. Epub 2014 Oct 23.

Istituto Nanoscienze - CNR, National Nanotechnology Laboratory (NNL), Via Arnesano, 73100 Lecce, Italy; Dipartimento di Ingegneria dell'Innovazione, Università del Salento, Via Monteroni, 73100 Lecce, Italy. Electronic address:

Background: 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.
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http://dx.doi.org/10.1016/j.bbagen.2014.10.010DOI Listing
February 2015

Computational evidence for structural consequences of kiteplatin damage on DNA.

J Biol Inorg Chem 2015 Jan 7;20(1):35-48. Epub 2014 Nov 7.

School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.

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 (1)H-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.
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http://dx.doi.org/10.1007/s00775-014-1207-5DOI Listing
January 2015

DNA fragment conformations in adducts with Kiteplatin.

Dalton Trans 2015 Feb;44(8):3544-56

Dipartimento di Chimica, Università degli Studi di Bari A. Moro, via E. Orabona, 4, 70125 Bari, Italy.

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'-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'- and/or 5'-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 °C) HH1 and ΔHT1 conformers are present in comparable amounts. In contrast, at low temperature (close to 0 °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).
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http://dx.doi.org/10.1039/c4dt01796jDOI Listing
February 2015

Insertion of alkynes into Pt-X bonds of square planar [PtX2(N^N)] (X = Cl, Br, I) complexes.

Dalton Trans 2014 Jun;43(23):8826-34

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Monteroni, I-73100 Lecce, Italy.

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(η(2)-CH≡CH)(Me2phen)], that evolve to four-coordinate alkenyl complexes of the type [PtX(η(1)-E-CH=CHX)(Me2phen)]. The alkenyl complexes, in the presence of excess acetylene, establish an equilibrium with the five-coordinate alkyne-alkenyl species [PtX(η(1)-E-CH=CHX)(η(2)-CH≡CH)(Me2phen)] (X = Br, I). The π-bonded acetylene can be exchanged with free olefins or C≡O, affording the new alkene-alkenyl or carbonyl-alkenyl complexes [PtX(η(1)-E-CH=CHX)(η(2)-olefin)(Me2phen)] and [PtX(η(1)-E-CH=CHX)(C≡O)(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(η(1)-E-CH[double bond, length as m-dash]CHBr)(η(2)-CH2=CH2)(Me2phen)].
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http://dx.doi.org/10.1039/c4dt00679hDOI Listing
June 2014

First-time comparison of the in vitro antimalarial activity of Artemisia annua herbal tea and artemisinin.

Trans R Soc Trop Med Hyg 2012 Nov 15;106(11):696-700. Epub 2012 Sep 15.

Laboratory of Hygiene, Department of Biological and Environmental Science and Technology (DiSTeBA), University of Salento, Via Prov. le Lecce-Monteroni, 73100 Lecce, Italy.

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 ((1)H-NMR). Results of the in vitro tests were consistent with the clinical efficacy of A. annua tea [50% inhibitory concentration (IC(50)) for strain D10=1.11±0.21 μg/ml; IC(50) for strain W2=0.88±0.35 μg/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.
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http://dx.doi.org/10.1016/j.trstmh.2012.07.008DOI Listing
November 2012

Phytochemical analysis of a herbal tea from Artemisia annua L.

J Pharm Biomed Anal 2012 Mar 18;62:79-86. Epub 2012 Jan 18.

Dipartimento Farmaco-Chimico, Università Aldo Moro, Via Orabona 4, I-70125 Bari, Italy.

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.
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http://dx.doi.org/10.1016/j.jpba.2012.01.015DOI Listing
March 2012

Hard/soft selectivity in ligand substitution reactions of beta-diketonate platinum(II) complexes.

Dalton Trans 2009 Oct 31(37):7786-95. Epub 2009 Jul 31.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, prov.le Lecce/Monteroni, I-73100, Lecce, Italy.

The reactivity of platinum(II) complexes of the type [PtCl(O,O-acac)(L)] (1) and [Pt(O,O-acac)(gamma-acac)(L)] (2) (L = DMSO, a; DMS, b), with a range of hard and soft nucleophiles such as dimethylsulfide (DMS, b), triphenylphosphine, (PPh3, c), ethylene (eta2-C2H4, d), carbon monoxide (CO, e), pyridine (py, f), and guanosine (Guo, g) has been investigated. Interestingly, the complexes 1a and 1b undergo selective substitution of the chloro or sulfur ligand depending on the hard/soft character of the incoming nucleophile. The soft incoming ligand replaces the softer one and the hard ligand replaces the harder one, giving [PtCl(O,O'-acac)(L)] complexes (1b, 1c, 1d and 1e in the reaction of 1a with L = DMS, PPh3, eta2-C2H4, CO, respectively), and [Pt(O,O'-acac)(DMSO)(L')] (3f, 3g) and [Pt(O,O'-acac)(DMS)(L')] (4f, 4g) species in the reaction of 1a and 1b with L' = py and guo, respectively. In the cases of 2a and 2b complexes, where the pi-bonded acac (gamma-acac) replaces the chloro ligand, only in the presence of an incoming soft nucleophile substituting the soft sulfur ligand the reaction occurs. Equilibrium constants for the substitution reactions were measured by 1H NMR spectroscopy. Variable temperature 1H NMR spectroscopy studies, performed for the reaction of 1a and 2a complexes with DMS, revealed that the selective substitution of DMSO with DMS takes place in both cases, according to a second-order kinetic law. The calculated values of DeltaH++ and DeltaS++ are consistent with an associative mechanism. NMR spectroscopic characterization (1H, 13C, 195Pt, 31P) for the complexes and crystal structures of isolated complexes ([PtCl(O,O'-acac)(L)] (1) and [Pt(O,O'-acac)(gamma-acac)(L)] (2), L = DMSO, 1a and 2a; L = DMS, 1b and 2b; L = PPh3, 1c and 2c) are herein reported and discussed.
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http://dx.doi.org/10.1039/b909209aDOI Listing
October 2009

Comparison among different gilthead sea bream (Sparus aurata) farming systems: activity of intestinal and hepatic enzymes and 13C-NMR analysis of lipids.

Nutrients 2009 02 18;1(2):291-301. Epub 2009 Dec 18.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Prov.le Lecce-Monteroni, 73100, Lecce, Italy.

In order to evaluate differences in general health and nutritional values of gilthead sea bream (Sparus aurata), the effects of semi-intensive, land-based tanks and sea-cages intensive rearing systems were investigated, and results compared with captured wild fish. The physiological state was determined by measuring the activity of three different intestinal digestive enzymes: alkaline phosphatase (ALP), leucine aminopeptidase (LAP) and maltase; and the activity of the hepatic ALP. Also, the hepatic content in protein, cholesterol, and lipid were assessed. 13C-NMR analysis for qualitative and quantitative characterization of the lipid fraction extracted from fish muscles for semi-intensive and land based tanks intensive systems was performed. The lipid fraction composition showed small but significant differences in the monounsaturated/saturated fatty acid ratio, with the semi-intensive characterized by higher monounsaturated and lower saturated fatty acid content with respect to land based tanks intensive rearing system.
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http://dx.doi.org/10.3390/nu1020291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257603PMC
February 2009

New mononuclear and homodinuclear Pt(ii) complexes with heterocyclic nitrogen chelates: synthesis, characterization, intercalating ability and in vitro cytotoxic activity evaluation.

Dalton Trans 2008 Nov 11(43):5911-21. Epub 2008 Sep 11.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, prov.le Lecce/Monteroni, I-73100 Lecce, Italy.

A series of new mononuclear and dinuclear platinum(ii) compounds based on two bipyridyl systems, linked by an alkyl chain {1,2-bis[4-(4'-methyl-2,2'-bipyridinyl)]ethane, L2, (a), and 1,6-bis[4-(4'-methyl-2,2'-bipyridinyl)]hexane, L6, (b)} have been synthesized and characterized by IR and multinuclear and multidimensional NMR spectroscopy. The coordination sphere of the complexes, designed to give intercalating and/or covalent interactions with DNA, is completed only by exchangeable (Cl(-), I(-) or H(2)O) and/or not leaving (chelate ethylenediamine, en) saturating ligands. Quenching of the DNA-ethidium fluorescence was performed in order to verify the intercalating capability of the water soluble compounds. Furthermore, the in vitro cytotoxicity of all water soluble complexes has been assessed with respect to cisplatin on platinum-sensitive human endometrium (HeLa) and platinum-resistant human breast (MCF-7) cancer cell lines.
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http://dx.doi.org/10.1039/b807404fDOI Listing
November 2008

New water-soluble platinum(II) phenanthroline complexes tested as cisplatin analogues: First-time comparison of cytotoxic activity between analogous four- and five-coordinate species.

Dalton Trans 2006 Nov 25(42):5077-87. Epub 2006 Sep 25.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università di Lecce, Prov.le Monteroni/Lecce, I-73100, Lecce, Italy.

Four- and five-coordinate platinum(II) complexes, cis-[PtCl2(A2)] (1) and [PtCl2(A2)(eta2-ethylene)] (2) {A2 = 4,7-diphenyl-1,10-phenanthroline disulfonic acid disodium salt, BPS (mixture of isomers) (a); 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline disulfonic acid disodium salt, BCS (mixture of isomers) (b)} have been synthesized and characterized by 1H, 13C, and 195Pt NMR spectroscopy. The stability and high water solubility of complexes 1a, 1b and 2b, due to the presence of the polar SO3- groups on the ligands skeleton, allowed to test their in vitro cytotoxicity on HeLa tumour cells in a wide range of drug concentration. At low and medium incubation doses (<200 microM) 1a, 1b and 2b all showed similar in vitro cytotoxicity, negligible or much lower with respect to cisplatin. At doses higher than 200 microM their activity increased and 1b, the most active among the new complexes, exhibited a cytotoxicity comparable, although still lower, with respect to cisplatin. GFAAS Platinum analytical data showed that the tested compounds 1a, 1b and 2b, although carrying sulfonate charged groups, may undergo cellular uptake, which, in the case of 1b and 2b, is even higher with respect to cisplatin. Furthermore, in the case of 1b and 2b it has been possible to compare, for the first time, the cytotoxic activity for square-planar four-coordinate and trigonal-bipyramidal five-coordinate platinum(II) complexes having the same carrier ligand. The tendency of the five-coordinate species 2b to give at longer incubation time similar cytotoxicity with respect to the square-planar compound 1b suggests a possible use of the trigonal-bipyramidal five-coordinate complexes as prodrugs.
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http://dx.doi.org/10.1039/b610945dDOI Listing
November 2006

Platinum-based antitumor drugs containing enantiomerically pure alpha-trifluoromethyl alanine as ligand.

J Med Chem 2005 Dec;48(24):7821-8

Dipartimento Farmaco-Chimico, Università di Bari, Via E. Orabona 4, I-70125 Bari, Italy.

Synthetic amino acids such as fluorinated alpha-amino acids are currently actively investigated for their biological activity. Herein, we report on the synthesis and characterization of platinum complexes containing an N,O-chelated pure enantiomer of alpha-trifluoromethylalanine (alpha-Tfm-Ala). The compounds are either anionic, K[PtCl2(alpha-Tfm-Ala)], or cationic, [PtAm2(alpha-Tfm-Ala)](NO3) (Am2= (NH3)2, ethylendiamine (en), 1,10-phenanthroline (phen), and 2,9-dimethyl-1,10-phenanthroline (Me2phen)). All complexes are highly soluble in water and have been fully characterized by NMR spectroscopy. In vitro cytotoxicity assays on different human tumor cell lines have been performed on some of the isolated compounds. [Pt(NH3)2(alpha-Tfm-Ala)] with R configuration of the amino acid proved to have an activity comparable to that of the reference compound cisplatin. Flow cytometric analysis on NCI-H460 tumor cells (absence of G2/M arrest, which instead is observed in the case of cisplatin) suggests a mechanism of action different from that of cisplatin.
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http://dx.doi.org/10.1021/jm0504003DOI Listing
December 2005

Platinum(II) complexes with antitumoral/antiviral aromatic heterocycles: effect of glutathione upon in vitro cell growth inhibition.

J Med Chem 2005 May;48(9):3364-71

Dipartimento Farmaco-Chimico, Università degli Studi di Bari, Via E. Orabona 4, 70125 Bari, Italy.

The compounds [Pt(Me(2)phen)(acy)(2)](NO(3))(2) (1), [Pt(Me(2)phen)(pen)(2)](NO(3))(2), [Pt(phen)(acy)(2)](NO(3))(2) (2), and [Pt(phen)(pen)(2)](NO(3))(2), containing the bidentate 1,10-phenanthroline (phen) or 2,9-dimethyl-1,10-phenanthroline (Me(2)phen, neocuproine) and the antiviral agents acyclovir (acy) or penciclovir (pen), show different in vitro toxicity, the Me(2)phen complexes being appreciably more toxic than the phen complexes. To explain the different behavior, we investigated the reaction of complexes 1 and 2 with glutathione (gamma-glutamylcysteinylglycine, GSH), a peptide believed to play an important role in driving the cellular effects of platinum drugs. The reaction led to different products, the phen complexes forming a stable binuclear mu-thiol-bridged species still containing the phenanthroline and the Me(2)phen complexes releasing the neocuproine ligand and forming an insoluble material. In vitro tests confirmed that the greater cell toxicity of complex 1 is due to the displacement of the neocuproine ligand by GSH. The results highlight the great dependence of the glutathione reactivity upon relatively small changes in the platinum coordination sphere.
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http://dx.doi.org/10.1021/jm0500471DOI Listing
May 2005

Lipid-protein stoichiometries in a crystalline biological membrane: NMR quantitative analysis of the lipid extract of the purple membrane.

J Lipid Res 2002 Jan;43(1):132-40

Dipartimento di Fisiologia Generale ed Ambientale, Università di Bari, Via Amendola 165/a, 70126, Bari, Italy.

The lipid/protein stoichiometries of a naturally crystalline biological membrane, the purple membrane (PM) of Halobacterium salinarum, have been obtained by a combination of (31)P- and (1)H-NMR analyses of the lipid extract. In total, 10 lipid molecules per retinal were found to be present in the PM lipid extract: 2-3 molecules of phosphatidylglycerophosphate methyl ester (PGP-Me), 3 of glycolipid sulfate, 1 of phosphatidylglycerol, 1 of archaeal glycocardiolipin (GlyC), 2 of squalene plus minor amounts of phosphatidylglycerosulfate (PGS) and bisphosphatidylglycerol (archaeal cardiolipin) (BPG) and a negligible amount of vitamin MK8. The novel data of the present study are necessary to identify the lipids in the electron density map, and to shed light on the structural relationships of the lipid and protein components of the PM.
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January 2002