Domenico Montesano

Antibacterial and allelopathic activity of extract from Castanea sativa leaves.

Following the extraction of Castanea sativa with an aqueous solution of sulfuric acid (pH 3.0), the ethyl acetate soluble fraction was tested for its antibacterial and allelopathic activity. The extract was shown to have pronounced antibacterial effects against seven of the eight strains of Gram-positive and Gram-negative bacteria used (MIC in the range of 64-256 microg/ml and MBC in the range of 256-512 microg/ml). The active fraction was analyzed by TLC and HPLC showing the presence of rutin, hesperidin, quercetin, apigenin, morin, naringin, galangin and kaempferol. Standards of the identified flavonoids were tested against the same bacterial strains. The highest activity was shown by quercetin, rutin and apigenin. The allelopathic effect was tested against Raphanus sativus seed germination. The extract, quercetin, rutin and apigenin caused a decrease in the percentage of seed germination and root and epicotyl growth.

Determination of Bisphenol A and Bisphenol B Residues in Canned Peeled Tomatoes by Reversed-Phase Liquid Chromatography

Bisphenol A (BPA) and bisphenol B (BPB) concentrations were determined in peeled canned tomatoes of different brands bought in Italian supermarkets. Tomato samples analyzed were packaged in cans coated with either epoxyphenolic lacquer or low BADGE enamel. A solid phase extraction (SPE) was performed on C-18 Strata E cartridge followed by a step on Florisil cartridge. Detection and quantitation were performed by a reversed phase high-performance liquid chromatography (RP-HPLC) method with both UV and fluorescence detection (FD). On the total of 42 tested tomato samples, BPA was detected in 22 samples (52.4%), while BPB was detected in 9 samples (21.4%). BPA and BPB were simultaneously present in 8 of the analyzed samples. The levels of BPA found in this study are much lower than the European Union migration limits of 3 mg/kg food and reasonably unable to produce a daily intake exceeding the limit of 0.05 mg/kg body weight, established by European Food Safety Authority.

Determination of neonicotinoid insecticides residues in bovine milk samples by solid-phase extraction clean-up and liquid chromatography with diode-array detection

In this paper we have developed an analytical method for the simultaneous determination of four nicotinoid insecticides [acetamiprid (ACT), imidacloprid (ICL), thiacloprid (TCL) and thiamethoxam (TMX)] in bovine whole milk. These analytes were extracted, in a single step with dichloromethane, from fortified milk samples, using Chem Elut cartridges, containing diatomaceous earth material. Insecticides determination and quantification were performed by HPLC with diode-array detection (DAD). Average recoveries of the four insecticides from bovine milk samples were between 85.1 and 99.7% at spiking levels 0.01, 0.05 and 0.1 mg kg(-1). Relative standard deviations (RSDs) were no larger than 10% for all of the recovery tests. The calculated limits of quantitation (LOQ) ranged from 0.01 to 0.04 mg kg(-1) for the four insecticides, being equal to or lower than the maximum residue limits (MRLs) established by European legislation (0.01-0.05 mg kg(-1)). The developed method is linear at concentrations within the tested interval, with coefficients of determination higher than 0.9990. According to Commission Decision 2002/657/EC, decision limit (CCalpha) and detection capability (CCbeta) have been calculated. The proposed method is rapid, simple and could be utilized for the routine analysis of pesticides residues.

THE DISTRIBUTION OF MINERALS AND FLAVONOIDS IN THE TEA PLANT (CAMELLIA SINENSIS)

Camellia sinensis is a plant growing in India, Sri Lanka, Java, Japan and its properties were known 4000 years ago. Since then, traditional Chinese medicine has recommended this plant for headaches, body aches and pains, digestion, depression, detoxification, as an energiser and, in general, to prolong life. Tea contains volatile oils, vitamins, minerals, purines, polyphenols, particularly carechins. We have analysed ten commercial teas from various countries to determine their mineral composition and we have analysed a green tea, an Oolong tea and a White tea to determine their polyphenols and flavonoids content. Our study shows that the variation of mineral composition, polyphenols and flavonoids are linked to different origins of the plant. For the determination of phenols compounds and flavonoids we used an HPLC apparatus and for mineral analysis an atomic absorption apparatus.

Development and validation of a solid-phase extraction method coupled to high-performance liquid chromatography with ultraviolet-diode array detection for the determination of sulfonylurea herbicide residues in bovine milk samples

This study proposes a fast, simple and sensitive liquid chromatography diode array detector (LC/UV-DAD)-based method for the simultaneous determination of eight sulfonylurea herbicides (bensulfuron methyl, chlorsulfuron, metsulfuron methyl, primisulfuron methyl, rimsulfuron, thifensulfuron methyl, triasulfuron and tribenuron methyl) in bovine whole milk at concentrations lower than the default limit of 0.01 mg kg(-1) allowed by current legislation (Regulation EC/396/2005 and following Annexes). An effective one-step solid phase extraction (SPE) and clean up procedure was defined with use of Chem Elut cartridges, providing good recoveries for all the analytes tested and with no matrix effects affecting method accuracy. Separation of herbicides was obtained on a C(18) column by acetonitrile- water gradient elution. Method validation has been performed according to European Commission Decision 2002/657/EC criteria, in terms of linearity, recovery, precision, specificity, decision limit (CC(α)) and detection capability (CC(β)). Typical recoveries ranged between 78.4% and 99.7%, at the maximum residue limits (MRLs) levels established by Regulation EC/396/2005, with relative standard deviations (RSD) no larger than 10%.

Determination of five bisphenols in commercial milk samples by liquid chromatography coupled to fluorescence detection.

The presence of five bisphenols, i.e., bisphenol F, bisphenol A, bisphenol B, bisphenol F diglycidyl ether, and bisphenol A diglycidyl ether, was monitored in commercial milk packed in plastic bottles marketed in Italy. The new validated method includes a solid-phase extraction procedure followed by liquid chromatography with fluorescence detection. All positive results were confirmed by liquid chromatography-tandem mass spectrometry analysis. The limits of detection and quantification and the recovery percentages indicated that the method is suitable for detecting bisphenols in milk at concentrations far below the legal limits. Of 68 commercial milk samples analyzed, no bisphenol was found in 27 samples (39.7%), and 41 samples (60.3%) contained one or more bisphenols. The bisphenol most frequently found was bisphenol F (36 samples, 52.9%) followed by bisphenol A (20 samples, 29.4%) and bisphenol B (6 samples, 8.8%). Taking into consideration the limits of detection, no sample contained either bisphenol F diglycidyl ether or bisphenol A diglycidyl ether.

Potent relaxant effect of a Celastrus paniculatus extract in the rat and human ileum

ETHNOPHARMACOLOGICAL IMPORTANCE Celastrus paniculatus Willd. (Celastraceae) is an Ayurvedic remedy used for the treatment of a number of diseases, including bowel spasms. AIM OF THE STUDY To investigate the mode of the relaxing action of a methanolic extract prepared from the seeds of Celastrus paniculatus (CPE, 0.0001-10 microg/mL) in the rat ileum and to try to confirm on human tissues the intestinal pharmacological activity of the extract. MATERIALS AND METHODS The relaxant effect of CPE was studied in vitro by evaluating its effect on the spontaneous contractions of the isolated ileum. RESULTS CPE exerted a tetrodotoxin- and omega-conotoxin-resistant inhibitory effect on rat ileum motility (IC(50): 0.24+/-0.02 microg/mL; E(max): 99.0+/-0.60%). The inhibitory effect was reduced by nifedipine but not by cyclopiazonic acid. Experiments with specific antagonists enabled us to exclude the involvement of the main endogenous spasmogenic (i.e. acetylcholine and tachykinins) and relaxing (noradrenaline, nitric oxide, ATP) compounds. CPE also relaxed the isolated human ileum (IC(50): 0.26+/-0.02 microg/mL; E(max): 99.1+/-0.46%). CONCLUSION It is concluded that (i) CPE exerted a powerful myogenic and L-type Ca(2+)-dependent relaxing effect in the isolated rat ileum and that (ii) the human ileum is sensitive to the inhibitory effect of CPE. If confirmed in vivo, our data could explain the traditional use of this herb in the treatment of intestinal spasms.

Impact of boiling on free and bound phenolic profile and antioxidant activity of commercial gluten-free pasta

Cooking by boiling dry pasta could have varying degrees of influence on nutritional and functional components. In the present study, its effect on total phenolic content and antioxidant capacity, as well as on the comprehensive profile of free and bound phenolics, was investigated in six commercial gluten-free (GF) pasta products. Overall, the heat treatment caused a significant reduction (P<0.01) of the total phenolic content as well as FRAP reducing power and ORAC radical scavenging, with significant differences among the pasta samples considered. The highest values were recorded in free phenolic fraction remaining in black rice (41mggallic acid equivalents100g-1 and 25mmolTrolox Equivalents100g-1) and quinoa (24mggallic acid equivalents100g-1 and 14mmolTrolox Equivalents100g-1) cooked GF pasta. Significant correlations (P<0.01) could be found between total phenolics and both the antioxidant capacity assays performed. UHPLC-ESI/QTOF-MS mass profiling allowed confirming the spectrophotometric results, while identifying the amount of free and bound fractions. Among phenolic classes, lignans exhibited the highest decrease during the cooking process, followed by stilbenes and flavonoids. However, phenolic acids and other phenolics showed the highest stability. Furthermore, cooking by boiling strongly lowered the bound-to-free ratio of phenolic compounds, by an averaged factor ranging from 14-folds for flavonoids to 5-folds for other classes of phenolics.

Determination of dimethyl fumarate in desiccant and antimould sachets by reversed-phase liquid chromatography

A method for the determination of dimethyl fumarate (DMF) in desiccant and antimould sachets, employed for protecting consumer products from humidity and mould, has been developed. The method is based on a solid-liquid extraction followed by HPLC-UV analysis. The method was validated with respect to recovery, linearity, limits of detection and quantitation and precision. The recovery was 98%. The correlation coefficient value (r) was equal to 0.94. Both intra- and inter-day precisions were studied at several concentration levels, being satisfactory in all cases (RSD < 5). Limits of detection and quantification values were in the low microgram per gram level, thus allowing the determination of DMF at concentrations below the limit established (0.1 mg/kg) by the recent EU Directive (Decision 2009/251/EC). The proposed procedure was applied for the determination of the target compound in 41 desiccant and antimould samples. DMF was detected in 39.0% of samples and its content in many samples exceeded the legal limits. The results of our analysis highlight the high risk of exposure to this powerful allergic sensitizer for consumers.

A Simple HPLC-ELSD Method for Sugar Analysis in Goji Berry

Fructose, glucose, and sucrose were identified and quantified in commercial samples of Lycium barbarum L. fruits (goji berries) by high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) method. This study described a rapid, simple, sensitive, selective, and reliable HPLC method suitable for the profiling of major sugars in berries, the evaluation of the nutritional/energetic properties, and assessment of the maturation stage. The proposed analytical method was validated and the results showed good precision, accuracy, and linearity. In all analyzed goji fruits, glucose and fructose were the predominant sugars, while sucrose content was about ten times lower than each monose. It was observed that glucose and fructose were detected in comparable quantities in all considered samples. Quantitative analysis showed that fructose, glucose, and sucrose content ranged from 154.20 to 259.13 mg g−1, from 152.92 to 284.60 mg g−1, and from 13.75 to 36.43 mg g−1, respectively.