Felice Filizzola

Localization and interactions of melatonin in dry cholesterol/lecithin mixed reversed micelles used as cell membrane models

Abstract:  The state of melatonin confined in dry cholesterol/lecithin mixed reversed micelles dispersed in CCl4 was investigated using 1H‐NMR and FT‐IR spectroscopies as a function of the melatonin to lecithin molar ratio (RMLT) and of the cholesterol to lecithin molar ratio (RCHL). An analysis of experimental results leads to the hypothesis that, independent of RMLT and as a consequence of anisotropic melatonin/lecithin, melatonin/cholesterol and cholesterol/lecithin interactions, melatonin is totally solubilized in reversed micelles. Melatonin is mainly located in and oriented in the nanodomain constituted by the hydrophilic groups of cholesterol and lecithin. A competition of melatonin and cholesterol for the hydrophilic binding sites of the reversed micelles was observed by changing the RCHL. Some possible biological implications of the specific interactions governing the solubilization process, the preferential location and the peculiar properties of melatonin confined in cholesterol/lecithin mixed reversed micelles are discussed.

Fruit physical, chemical and aromatic attributes of early, intermediate and late apricot cultivars

BACKGROUND In order to reach good fruit quality, apricots require a balance of sugars and acids as well as a strong apricot aroma. In this study, fruit quality of early, intermediate and late apricot cultivars was evaluated by measuring physical, chemical and olfactory attributes. Multivariate analysis of quality and aroma attributes was used to identify groups of similar cultivars and association with ripening season. RESULTS Physical, chemical and aromatic attributes showed great variation among cultivars but no relation to ripening season. Aromatic profiles (34 volatiles) of fruit tissues indicated qualitative and quantitative differences among cultivars. Ninfa and Mandorlon were richest in aroma, with a prevailing fruity component; Goldrich and Orange Red were also highly aromatic, with all odour components well represented; Pinkot, Alba and Pellecchiella were lowest in aroma, with a prevailing grassy component. Linear functions including five volatiles (concentrations) and fruit diameter or six aromatic compounds (odour units) and peel colour were found to discriminate cultivars by ripening season. Principal component analysis individuated three groups of cultivars: Ninfa and Mandorlon with sweet and fruity-flavoured fruits; Bulida, Alba, Goldrich, Ouardy and Silvercot with large, acidic and well-coloured fruits; and Fracasso, Pellecchiella, Palummella and Pinkot with small and floral/grassy-flavoured fruits. CONCLUSION In apricot, detailed analysis of the aromatic profile may represent an efficient tool for classification of genotypes by ripening season, and volatiles with relevant odour contribution may serve as quality markers for selecting towards an extended ripening season of best quality apricots.

Melatonin: structural characterization of its non-enzymatic mono-oxygenate metabolite

Abstract: Oxidation of melatonin by Fenton reagents as well as with hypochlorous acid or oxoferryl hemoglobin has been investigated. Analysis of products by low resolution/mass spectra (MS), high resolution/MS, 1H‐nuclear magnetic resonance (NMR), 13C‐NMR, correlated spectroscopy (COSY) and heterocorrelated spectroscopy (HETCOR) 2D NMR reveals the formation of a single mono‐oxygenated product under all conditions and unequivocally assigns the N‐[2‐(5‐methoxy‐2‐oxo‐2,3‐dihydro‐1H‐indol‐3‐yl)‐ethyl]‐acetamide structure, which had not been previously considered.

Determination of terpene alcohols in Sicilian Muscat wines by HS-SPME-GC-MS

Muscat is a grape family used to obtain several sweet, aromatic white dessert wines common in the Mediterranean area. Currently, three Sicilian cultivars (all classified DOC) are known: ‘Moscato di Siracusa’ the oldest and very rare today; ‘Moscato di Noto’, a modern derivative of the first and finally ‘Moscato di Pantelleria’, now the most common. This study concerns the volatile profile of 15 different Sicilian Muscat wines produced in different years using HS-SPME-GC-MS. In particular, four fundamental terpene alcohols (linalool, geraniol, nerol and citronellol) were considered. The principal aim was to study the evolution of aromatic compounds in wine during aging, and the information obtained is useful for production and marketing. It was found that the amount of terpenes decreased with aging, thereby reducing the quality characteristic of these wines. An accurate analysis of chromatograms could characterise Muscat wines on the basis of geographic origin.