Docosahexaenoic Acid Levels in Blood and Metabolic Syndrome in Obese Children: Is There a Link?

Prevalence of metabolic syndrome is increasing in the pediatric population. Considering the different existing criteria to define metabolic syndrome, the use of the International Diabetes Federation (IDF) criteria has been suggested in children. Docosahexaenoic acid (DHA) has been associated with beneficial effects on health. The evidence about the relationship of DHA status in blood and components of the metabolic syndrome is unclear. This review discusses the possible association between DHA content in plasma and erythrocytes and components of the metabolic syndrome included in the IDF criteria (obesity, alteration of glucose metabolism, blood lipid profile, and blood pressure) and non-alcoholic fatty liver disease in obese children. The current evidence is inconsistent and no definitive conclusion can be drawn in the pediatric population. Well-designed longitudinal and powered trials need to clarify the possible association between blood DHA status and metabolic syndrome.     

A New Formulation Based on Ozonated Sunflower Seed Oil: In Vitro Antibacterial and Safety Evaluation

The objective of this study was to investigate the potential in vitro biological properties of Oz.Or.Oil 30, a new formulation composed of 30% ozonated sunflower seed oil, which is believed to keep skin smooth and moisturized, supporting repair processes, tissue regeneration and re-epithelialization of wounds. The antibacterial activity, the qualitative and quantitative evaluation of the cytotoxic effect of the formulation on cultures of Vero cells and 3T3 fibroblasts showed that Oz.Or.Oil 30 merits further in vivo study using clinical-laboratory correlations, because it could be suggested as an alternative therapy against bacterial and fungal diseases.     

Synthesis and Characterization,Including Cancer Cell Line Inhibition,of Group VA (Group 15)-Containing Polyesters from Reaction with Camphoric Acid

Polyesters were rapidly synthesized employing interfacial polymerization from reaction of the salt of camphoric acid with Group VA (Group 15) triphenylmetallic dihalides. Yields range from 25 to 46 percent with chain lengths about 250. Infrared spectroscopy shows the formation of two new bands one assigned to the symmetrical M–O stretching and the second assigned to the asymmetrical M–O stretching. The bridging structure about the metal atom increases as the metal atom size increases. MALDI MS and proton NMR are consistent with the formation of the polyester structure. Ion fragment clusters to four to six units are identified. The polymers show good inhibition of a group of cancer cell lines including two pancreatic human cancer cell lines. In comparison with other metal/camphoric acid polymers, the metallocene polymers exhibit low EC₅₀ to the nanogram/ml range, and CI₅₀ values greater than one thousand for the hafnocene and zirconocene products. If this trend continues, the emphasis should be on the Group IVB metallocenes with respect to efforts to create anticancer drugs.     

Macrocyclization of Organo‐Peptide Hybrids through a Dual Bio‐orthogonal Ligation: Insights from Structure–Reactivity Studies

Macrocycles constitute an attractive structural class of molecules for targeting biomolecular interfaces with high affinity and specificity. Here, we report systematic studies aimed at exploring the scope and mechanism of a novel chemo‐biosynthetic strategy for generating macrocyclic organo‐peptide hybrids (MOrPHs) through a dual oxime‐/intein‐mediated ligation reaction between a recombinant precursor protein and bifunctional, oxyamino/1,3‐amino‐thiol compounds. An efficient synthetic route was developed to access structurally different synthetic precursors incorporating a 2‐amino‐ mercaptomethyl‐aryl (AMA) moiety previously found to be important for macrocyclization. With these compounds, the impact of the synthetic precursor scaffold and of designed mutations within the genetically encoded precursor peptide sequence on macrocyclization efficiency was investigated. Importantly, the desired MOrPHs were obtained as the only product from all the different synthetic precursors probed in this study and across peptide sequences comprising four to 15 amino acids. Systematic mutagenesis of the “i?1” site at the junction between the target peptide sequence and the intein moiety revealed that the majority of the 20 amino acids are compatible with MOrPH formation; this enables the identification of the most and the least favorable residues for this critical position. Furthermore, interesting trends with respect to the positional effect of conformationally constrained (Pro) and flexible (Gly) residues on the reactivity of randomized hexamer peptide sequences were observed. Finally, mechanistic investigations enabled the relative contributions of the two distinct pathways (side‐chain→C‐end ligation versus C‐end→side‐chain ligation) to the macrocyclization process to be dissected. Altogether, these studies demonstrate the versatility and robustness of the methodology to enable the synthesis and diversification of a new class of organo‐peptide macrocycles and provide valuable structure–reactivity insights to inform the construction of macrocycle libraries through this chemo‐biosynthetic strategy.     

Photoactive sol–gel hybrid coatings from modified fluorocarbon polymers and amorphous titania

A series of organic–inorganic hybrid coatings was prepared through sol–gel chemistry by combining silanized chlorotrifluoroethylene-vinylether (FEVE) binders with tetraalkoxy silicon and titania sols under acidic conditions. The best compositions to obtain highly transparent and homogeneous coatings after thermal curing were determined. All the hybrid coatings easily pass the MEK test and show high scratch hardness. The atomic force microscopy (AFM) shows the formation of very smooth surfaces (R_rms routinely <1 nm) without clear phase separation phenomena. The typical size of the “objects” which may be individuated is in the range of 40–80 nm. Wettability through contact angle measurements shows the formation of moderately hydrophobic surfaces with a low contact angle hysteresis (~20°) which is a further indication of very smooth, homogeneous and chemically stable surfaces. After irradiation with UV-B light only hybrid coatings containing titania phases show a significant switch to a superhydrophilic behavior with a contact angle against H₂O down to 6°, which is only partially recovered after storage of the material in the dark. Titania based hybrid coatings also showed a fast and efficient UV-induced discoloration of the resazurin ink. The formulation of the coatings with photostabilizers belonging to the class of radical scavengers and UV absorbers does not change the photoinduced surface properties while eliminating the yellowing of the coating after UV exposure. It is concluded that titania-fluoropolymer hybrid coating show photoactivity and UV-induced superhydrophylicity mostly through ionic mechanisms, which could be beneficial to develop high durability and self-cleaning protective coatings.     

Synthesis, Molecular Characterization and Preliminary Antioxidant Activity Evaluation of Quercetin Fatty Esters

Quercetin shows interesting pharmacological effects, but its use in topical applications is limited by its low skin permeability and solubility. In this work, the synthesis of highly lipophilic quercetin esters with oleic, linoleic and linolenic acid useful as topical quercetin prodrugs is reported. Partial OH esterification is advisable to maintain the antioxidant activity of these compounds; tetraesters and triesters can be achieved by modulating the reaction conditions utilized for the total esterification of quercetin. The chemical structures of the esters were proven by spectroscopic techniques; quantum chemical NMR calculation were mandatory to unequivocally assign the free position in triesters. Finally, the antioxidant activity of all the synthesized compounds was determined by the 2,2-diphenyl-1-picryl-hydrazyl method and by 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) assay.     

Hybrid MCM-41 grafted by a general microwave-assisted procedure: a characterization study

Hybrid materials obtained through a Microwave-assisted grafting of organic functional groups on mesoporous silica (MCM-41 type) have been characterized by X-ray powder diffraction, TG-DSC, N₂ adsorption, solid state ¹³C- and ²⁹Si-NMR, TEM and SEM. The studied grafting procedure is effective in the preparation of hybrid organosilicas under solvent-free conditions. Microwaves allows an ultra-fast and clean functionalization of the mesoporous materials and the method has been applied to produce a wide series of functional materials. The hybrid materials maintain the original mesoporous structure when the loading of linked organic groups does not exceed 10 %. In this cases, the slight pore volume reduction is linearly correlated to the organic amount in the product. If functional groups able to interact among them through hydrogen bond are used, hybrid materials exhibit high Organic/SiO₂ ratios and low pore volumes due to the formation of a network occluding the pores, where functional groups of free organosilane molecules interacts with the functional groups of molecules linked to the matrix. NMR data confirm that the network is composed by organosilane molecules linked or not to the framework. Acid washing is able to labilize hydrogen bond and open the network. In the case of bulky but chemically inert functionalising agents the network is not produced.     

In situ growth of well-dispersed CdS nanocrystals in semiconducting polymers

A straight synthetic route to fabricate hybrid nanocomposite films of well-dispersed CdS nanocrystals (NCs) in poly[2-methoxy-5-(2''-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) is reported. A soluble cadmium complex [Cd(SBz)₂]₂·MI, obtained by incorporating a Lewis base (1-methylimidazole, MI) on the cadmium bis(benzyl)thiol, is used as starting reagent in an in situ thermolytic process. CdS NCs with spherical shape nucleate and grow well below 200°C in a relatively short time (30 min). Photoluminescence spectroscopy measurements performed on CdS/MEH-PPV nanocomposites show that CdS photoluminescence peaks are totally quenched inside MEH-PPV, if compared to CdS/PMMA nanocomposites, as expected due to overlapping of the polymer absorption and CdS emission spectra. The CdS NCs are well-dispersed in size and homogeneously distributed within MEH-PPV matrix as proved by transmission electron microscopy. Nanocomposites with different precursor/polymer weight ratios were prepared in the range from 1:4 to 4:1. Highly dense materials, without NCs clustering, were obtained for a weight/weight ratio of 2:3 between precursor and polymer, making these nanocomposites particularly suitable for optoelectronic and solar energy conversion applications.