The phenolic composition of Syrah and Chardonnay grape pomaces was studied to assess their antioxidant and prooxidant properties. Polyphenols were extracted by a "green" hydroalcoholic solvent (ethanol/water 1:1 v/v), and a detailed chemical and electrochemical characterization of the phenolic compounds was performed. The antioxidant and prooxidant capacity of the pomace was first studied by cyclic voltammetry (CV) and other reference analytical assays, then with biological tests on B16F10 metastatic melanoma cancer cells. Electrochemical data showed that, when a +0.5 V potential was applied, a low to moderate antioxidant capacity was observed. MTT test showed an increasing viability of melanoma cells, after treatments at low concentration (up to 100 µg/mL) and for a short time (6 h), but when cells were treated with higher doses of extract (≥ 250 µg/mL for 12/24 h), their viability decreased from 25 to 50% vs. control, depending on treatment time, dose, and extract origin. A stronger prooxidant activity resulted when 250 µg/mL of extract was combined with non-toxic doses of H2O2; this activity was correlated with the presence of copper in the extracts. This study shows the potential of winemaking by-products and suggests the opportunity to exploit them for the production of cosmeceuticals, or for combined therapies with approved anticancer drugs.
Quassia amara wood chips are used by organic farmers as a valid alternative to synthetic insecticides. The powder of Q. amara contains high levels of quassin, neoquassin and picrasinoside B. In this study we developed a liquid chromatography mass spectrometry method for the rapid and accurate quantification of the insecticide quassinoids on fruits and vegetables. Quassinoids were extracted from fruits and vegetables with acetonitrile and separated on a Zorbax Column Eclipse XDB C8 by isocratic elution with a mobile phase consisting of water and methanol with 0.1% of formic acid. Using a high-performance liquid chromatograph coupled with an electrospray ionization tandem mass spectrometer (HPLC/ESI-MS/MS), quassinoids were selectively and simultaneously detected monitoring the multiple reaction (MRM) transitions of proton adduct precursor ions: m/z 389.5 --> 222.9 for quassin, 391.5 --> 372.9 for neoquassin and 576.1 --> 394.5 for picrasinoside B. For all quassinoids calibration was linear over a working range of 1 and 100 microg/kg with r > 0.991. Limit of determination (LOD) and limit of quantification (LOQ) for both quassinoids were 0.5 and 1 microg/kg respectively while for picrasinoside B they were 5 and 10 microg/kg. Quassinoid recoveries ranged from 85.3% to 105.3% with coefficients of variation between 2.5% and 12.8% for fruit and vegetables. The presence of interfering compounds in the fruit and vegetable extract was evaluated and found to be minimal. Due to the linear behavior it was concluded that the multiple reaction transitions of precursor ions can be used for analytical purposes, i.e. for identification and quantification of quassin, neoquassin, and picrasinoside B in fruit and vegetable extracts at trace levels.
Cephalopods are known to accumulate cadmium and play an important role in its biomagnification. They are an essential link in marine trophic chain and represent an important case in studies on cadmium transfer to man through the food chain. Since cadmium concentration widely varies in different tissues of the cephalopods – mainly accumulating in the hepatopancreas – evisceration represents a recommended preliminary step to reduce cadmium intake in view of cephalopods consumption; yet, the residual concentration in the edible part may still be a risk for public health. This study is intended to assess cadmium levels variability in the muscles of Cephalopoda, considering the different feeding habitats and marine trophic webs. In compliance with EU regulation, a survey on cadmium and other heavy metal levels in various sea food, including cephalopods, was conducted by the Istituto Zooprofilattico of Sardinia in co-operation with local health authorities. During a five-year survey (2008- 2012), 90 samples were collected from the following species: commons octopus (Octopus vulgaris), cuttlefish (Sepia officinalis), European squid (Loligo vulgaris), and flying squid (Todarodes sagittatus), located in different coastal areas and representatives of either benthic or nektonic habitats. Determination of cadmium levels was carried out according to Regulations (EC) No. 882/2004, No. 1881/2006 and No. 333/2007. Analysis of the edible portion (muscle) of fresh homogenised samples was carried out by inductively coupled plasma mass spectrometry (ICP-MS). The results showed a highly skewed distribution of data. No statistically significant differences were observed among four distributions of the natural logs of cadmium levels in the species considered
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