1,721,140 research outputs found
Genome-wide analysis and expression profiling of glyoxalase I genes in durum wheat (Triticum durum Desf.) under hyperosmotic stress
No full textFirst evidence of a protective effect of plant bioactive compounds against h2o2-induced aconitase damage in durum wheat mitochondria
No full textIn order to contribute to the understanding of the antioxidant behavior of plant bioactive compounds with respect to specific subcellular targets, in this study, their capability to protect aconitase activity from oxidative-mediated dysfunction was evaluated for the first time in plant mitochondria. Interest was focused on the Krebs cycle enzyme catalyzing the citrate/isocitrate interconversion via cis-aconitate, as it possesses a [4Fe-4S]2+ cluster at the active site, making it an early and highly sensitive target of reactive oxygen species (ROS)-induced oxidative damage. In particular, the effect on the aconitase reaction of five natural phenols, including ferulic acid, apigenin, quercetin, resveratrol, and curcumin, as well as of the isothiocyanate sulforaphane, was investigated in highly purified mitochondria obtained from durum wheat (DWM). Interestingly, a short-term (10 min) DWM pre-treatment with all investigated compounds, applied at 150 μM (75 μM in the case of resveratrol), completely prevented aconitase damage induced by a 15 min exposure of mitochondria to 500 μM H2O2. Curcumin and quercetin were also found to completely recover DWM-aconitase activity when phytochemical treatment was performed after H2O2 damage. In addition, all tested phytochemicals (except ferulic) induced a significant increase of aconitase activity in undamaged mitochondria. On the contrary, a relevant protective and recovery effect of only quercetin treatment was observed in terms of the aconitase activity of a commercial purified mammalian isoform, which was used for comparison. Overall, the results obtained in this study may suggest a possible role of phytochemicals in preserving plant mitochondrial aconitase activity, as well as energy metabolism, against oxidative damage that may occur under environmental stress conditions. Further investigations are needed to elucidate the physiological role and the mechanism responsible for this short-term protective effect
New thermoplastic elastomer triblock copolymer of PLLA for cardiovascular tissue engineering: Annealing as efficient tool to tailor the solid-state properties
No full textA new high molecular weight aliphatic copolyester of PLLA characterized by a ABA triblock architecture was successfully synthesized by ring opening polymerization, using as initiator a low molecular weight hydroxyl terminated random copolymer of PBS, poly(butylene/triethylene succinate). To increase the final polymer molecular weight, thus ensuring both good processability and mechanical properties, chain extension reaction has been performed with hexamethylene diisocyanate (HDI) as chain extender. All the synthetic steps have been carried out in solvent-free conditions. Specifically, the A block consists of LLA sequences, whereas the B one is an aliphatic biodegradable and biocompatible random copolyester of poly(butylene succinate) containing “PEG-like” moiety. The so-obtained material was first characterized by the molecular point of view and then, prior to further characterization, subjected to two different annealing treatments. Annealing revealed to be an efficient tool to control the kind and amount of crystalline phase developed by the material, as confirmed by WAXS structural analysis, and to tailor the mechanical properties, typical of thermoplastic elastomers. Thermal treatment was found to affect also the mechanism of polymer degradation under physiological conditions. Last, but not least, in order to explore the possible use of such new PLLA-based copolymer in vascular tissue engineering, preliminary biocompatibility tests, using endothelial cells, were carried out
New Random Aromatic/Aliphatic Copolymers of 2,5-Furandicarboxylic and Camphoric Acids with Tunable Mechanical Properties and Exceptional Gas Barrier Capability for Sustainable Mono-Layered Food Packaging
Full text linkHigh molecular weight, fully biobased random copolymers of 2,5-furandicarboxylic acid (2,5-FDCA) containing different amounts of (1R, 3S)-(+)-Camphoric Acid (CA) have been successfully synthesized by two-stage melt polycondensation and compression molding in the form of films. The synthesized copolyesters have been first subjected to molecular characterization by nuclear magnetic resonance spectroscopy and gel-permeation chromatography. Afterward, the samples have been characterized from a thermal and structural point of view by means of differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray scattering, respectively. Mechanical and barrier properties to oxygen and carbon dioxide were also tested. The results obtained revealed that chemical modification permitted a modulation of the abovementioned properties depending on the amount of camphoric co-units present in the copolymers. The outstanding functional properties promoted by camphor moieties addition could be associated with improved interchain interactions (π-π ring stacking and hydrogen bonds)
Biodegradation of polyvinyl chloride plastic films by enriched anaerobic marine consortia
Full text linkPlastics remarkably contribute to marine litter, which is raising serious concerns. Currently, little is known about the fate of most plastics entering the marine environment and their potential biodegradation rate and extent under anoxic conditions. In this work, biodegradation of polyvinyl chloride (PVC) films by consortia enriched from marine samples (litter and water) was evaluated in anaerobic microcosms. After 7 months, three microcosms showed dense biofilms on plastic surfaces, gravimetric weight losses up to 11.7 ± 0.6%, marked decreases in thermal stability and average molecular weight of the polymer, suggesting microbial attack towards polymer chains. After 24 months, further three consortia showed the same abilities. Microbial communities analyzed at month 24 included taxa closely related to those previously reported as halogenated organic compounds degraders. The study is the first report on PVC biodegradation by marine anaerobic microbes and provides insights on potential biodegradation of the plastic film introduced into the sea by native microbes
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