Vincenzo Amico

ABSTRACT From a screening of six different samples of grape stems from Vitis vinifera Sicilian cultivars, ‘Nerello Mascalese’ as well as ‘Nero d’Avola’ ethanol extracts showed promising radical scavenging activity and phenol content (DPPH� and GAE assays). Aliquots of these three extracts were subjected to two different fractionation protocols on polyamide (PF) and Amberlite XAD-16 (XF). The fractions were examined by DPPH� and GAE assays, and subjected to HPLC-DAD analysis for the quantitative determination of the main phenolic compounds. Fractionation of the crude extract NM1E (SC50 = 28.2, GAE = 221.0) through the XF protocol, afforded a polyphenol-enriched fraction (XF1C, GAE = 392.5) with highly enhanced antioxidant activity (SC50 = 7.0), and accounting for only 6.5% in weight of the NM1E extract. Fraction XF1C shows high concentrations of a procyanidin B1 (Pcd) and catechin (Cat). Some considerations on the relationship between antioxidant activity and phenolic HPLC-DAD profiles are also reported.

The fractionation, guided by cell-growth inhibition assay, of the EtOAc crude extract from grape stems of the Sicilian Vitis vinifera variety 'Nerello Mascalese' allowed identification often constituents, isolated either as pure compounds (1, 3-5, 7-10) or inseparable mixtures (2a-d and 6a-e). The pure constituents were: two triterpenoid acids, oleanolic (1) and betulinic acids (5); daucosterol (7); a stilbenoid, E-resveratrol (3) and its dimer E-epsilon-viniferin (4); the simple phenol gallic acid (8); and the flavanols catechin (9) and gallocatechin (10). Four 6'-O-acyldaucosterols (2a-d) and five 1,2-di-O-acyl-3-O-beta-D-galactopyranosyl glycerols (6a-e) were also identified as inseparable mixtures. All the isolated compounds were subjected to spectroscopic analysis and MTT bioassay on MCF-7 human breast cancer cells. The majority showed growth-inhibitory activity, 5 being the most active (GI50 = 0.57 microM). Compounds 3-5 were also tested on HT-29, U-87-MG and U-373...

... Abbott, OJ Perkins, EJ (1977). ... Concentrations of PCBs, BHCs and DDTs Residues in Seaweeds of the East Coast of Sicily VINCENZO AMICO, GIOVANNA ORIENTE, MARIO PIATTELLI andCORRADO TRINGALI Istituto Dipartimentale di Chimica a Chimica Industriale dell ...

... FROM THE BROWN ALGA ZONARIA TOURNEFORTII VINCENZO AMIGO, GIOVANNI NICOLOSI, GIOVANNA ORIENTE, MARIO PIATTELLI and CORRADO TRINGALI Istituto Dipartimentale di Chimica dell'Universita di Catania, V. le A. Doria, Catania, Italy (Received 22 June ...

The quantitative gas--liquid chromatographic analysis of non-protein amino acids, in the presence of protein amino acids, is described. The amino acids were determined as their N-trifluoroacetyl n-butyl esters on an ethylene glycol adipate column. The relative molar responses of 38 amino acids are reported.

Bioassay-guided fractionation of the EtOAc crude extract from Sicilian almond hulls, a waste material from Prunus dulcis crop, allowed identification of 10 constituents, isolated as pure compounds (1-5, 7, and 10) or unseparable mixtures (5 + 6 and 8 + 9). All compounds were subjected to spectroscopic analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide bioassay on MCF-7 human breast cancer cells. In addition to the main components oleanolic (1), ursolic (2), and betulinic (3) acids, the 2-hydroxy analogues alphitolic (4), corosolic (5), and maslinic (6) acids, as well as the related aldehydes, namely, betulinic (7), oleanolic (8), and ursolic (9), were identified. From a more polar fraction, the beta-sitosterol 3-O-glucoside (10) was also identified. A sample of commercially available betulin (11) was also included in bioassays as further support to a structure-activity relationship study. Betulinic acid showed antiproliferative activity toward MCF-7 cells (GI50 = 0.27 microM), higher than the anticancer drug 5-fluorouracil.

The methanolic extracts (MeOH) obtained from de-stemmed grape pomace samples of five Sicilian red grape cultivars (Nero d′Avola-NA, Nerello Mascalese-NM, Nerello Cappuccio-NC, Frappato-FR and Cabernet Sauvignon-CS) were evaluated for their DPPH and ABTS− radical scavenging capacity, and submitted to HPLC–UV–DAD and HPLC–MS–ESI analysis to determine the main polyphenolic constituents, namely anthocyanins and flavonols. All the MeOH extracts showed significant antioxidant activity, with some differences between the two methods employed. The NM sample was the most active in both tests. A large variability in the total anthocyanin (TA) and flavonol (TF) contents of the MeOH extracts, as well as in the quantitative distribution of the single anthocyanins and flavonols was observed. Statistically insignificant correlations between the TA+TF content and antioxidant activity, as measured by DPPH and ABTS− model systems (r2=0.0607, P>0.05; r2=0.3471, P>0.05), were established, but the most active sample, NM, showed the highest content of anthocyanins including a free catechol moiety in their structure.

The volatile components of grape pomace coming from the processing of some of the most important varieties of grape (Vitis vinifera L.) cultivated in Sicily, namely Nero d'Avola, Nerello Mascalese, Frappato and Cabernet Sauvignon, have been determined by gas-chromatography (GC) and gas-chromatography-mass spectrometry (GC-MS). According to the winemaking procedure that entails the removal of stalks before fermentation, two kinds of grape pomace are obtained. The first consists of skins, pulp residues and seeds, the proper grape pomace, which is partially used for grappa, a typical Italian spirit, and alcohol production, the second consists almost exclusively of stalks. On the whole, 38 components have been characterized in the samples of grape pomaces, with Frappato cv. showing the richest composition; instead, 88 components have been detected in the stalks of Frappato, Nero d'Avola, Nerello Mascalese and Cabernet Sauvignon varieties. In order to make a comparison between the grape varieties easier, the volatile components detected in the two sets of samples (grape pomaces and stalks) have been grouped in different classes. Significant differences among varieties have been detected and statistical treatment of data is also reported. This study is part of a wider project aimed at the possible exploitation of the main agro-industrial by-products. At the same time it is one of the first reports on the volatile components of this waste material.