Polyphenol Conjugates and Human Health: A Perspective Review

In recent years, antioxidants have gained great importance because of their potential use in food, pharmaceutical, and cosmetic industries. This interest is rooted in the cumulative evidence connecting active oxygen and free radicals with numerous human degenerative disorders, such as cardiovascular diseases, cancer, aging, and atherosclerosis. Polyphenols are the major class of antioxidant able to reduce the oxidative damages of lipids, proteins, enzymes, carbohydrates, and DNA in living cells and tissues. Among the realm of polyphenol compounds, polyphenol conjugates have been proposed as innovative materials which, by combining the advantageous properties of both the components, can increase the efficiency of antioxidants and their range of application in nutritional and biomedical fields. This work is an overview of the different class of polyphenol conjugates, which will be analyzed in terms of nutritional and biological properties, showing how these bio-conjugates will positively affect the human health.     

FORMATION OF SULFATE CONJUGATES METABOLITES IN THE DEGRADATION OF PHENANTHRENE,ANTHRACENE, PYRENE AND BENZO[A]PYRENE BY THE ASCOMYCETE ASPERGILLUS TERREUS

Abstract

The metabolism of four PAHs (phenanthrene, anthracene, pyrene and benzo(a)pyrene) by an Aspergillus terreus strain, isolated from a polluted soil, was investigated in liquid submerged culture. The main metabolites identified by the HPLC-MS technique, after solvent extraction of the fermentation broth and mycelium, were aryl-sulfates and hydroxyl-aryl-sulfates. A metabolic pathway was identified involving in sequence: the hydroxylation by a monooxygenase of the PAHs, the conjugation with a sulfate ion, followed by a further hydroxylation to hydroxyl-aryl-sulfates compounds. PAHs degradation by A. terreus yielded a different number of metabolite isomers depending on the type of the parent PAH. The environmental fate and ecotoxicity of the metabolite 9-phenanthrenesulfate was also investigated by a respirometric test of ready biodegradability and by a Vibrio fischeri acute toxicity test respectively. This compound was easily degradable by microbial consortia derived from polluted soil and capable of thriving on phenanthrene as its sole carbon source. Moreover the sulfate conjugate resulted in 2 orders of magnitude less toxic than its precursors phenanthrene.     

Microtiter spectrophotometric biofilm production assay analyzed with metrological methods and uncertainty evaluation

The microbial biofilm is a structure often developed by microorganisms when performing their harmful effects, both in the medical and industrial fields. Therefore, methods allowing identification and analysis of the biofilm play a fundamental role in determining the kind of intervention needed to avoid these effects. The microtiter spectrophotometric assay is recognized as the gold standard method to quantify a biofilm and to analyze the anti-biofilm activity of various substances. The aim of the present work is to validate this method through an uncertainty evaluation, covering eight different microbial species.     

Expression of different types of [FeFe]-hydrogenase genes in bacteria isolated from a population of a bio-hydrogen pilot-scale plant

[FeFe]-hydrogenases are the enzymes responsible for high yield H₂ production during dark fermentation in bio-hydrogen production plants. The culturable bacterial population present in a pilot-scale plant efficiently producing H₂ from waste materials was isolated, classified and identified by means of 16S rDNA gene analysis. The culturable part of the mixed population consists of nine bacterial species that include non-hydrogen producers (Lactobacillus, Enterococcus and Staphylococcus) and several Clostridium that are directly responsible for H₂ production.     

Fracture mechanics for the reconstruction of Noto Cathedral

The baroque buildings of Sicily should be ideal subjects of Fracture Mechanics, having heights up to 60 m, PGA up to 0.30×g, low strengths, few reinforcements, aggregate with irregular stones in the most vulnerable zones. Their analysis constitutes a severe test. The damages between the earthquake on 13.12.1990 and its collapse on 13.03.1996 are due to cracking development always. A monotonic static analysis by FE is performed here. Prestressing and lightening are examined.     

Excess electrons stabilized on ionic oxide surfaces

Surface excess electrons are remarkable chemical entities that provide great opportunities for the design of new materials with precisely tuned electronic and magnetic properties. In this Account, we describe the structure and electronic properties of excess electron centers generated at the surface of insulating oxides. We also outline the elementary mechanisms that are at the basis of the generation of excess electrons at solid surfaces, setting a comparison to the general problem of excess electron localization in condensed media. Emphasis is given to morphological aspects relative to the surface-trapping sites as deduced from combined electron paramagnetic resonance and accurate quantum chemical calculations. The remarkable reactivity featured by the so formed "electron-rich" surfaces is illustrated, describing the reduction of simple diatomic molecules that form adsorbed radical anions via direct surface to adsorbate electron transfer.