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21.
Here we report a simple and fast method for wine fingerprinting based on direct matrix-assisted laser desorption/ionization
(MALDI) mass spectrometry analysis of different red wine samples, useful for batch-to-batch analysis and for the detection
of key compounds even in trace amounts which may vary from vintage to vintage, and from one treatment to another one. A series
of 20 samples from different wines were subjected to MALDI mass spectrometry. We found that 2,5-dihydroxybenzoic acid is far superior with respect to all the matrices tested To the best of our knowledge this is the
first application of an effective wine profiling not limited to detection of anthocyanins. More than 80 molecular species
were detected. Moreover, qualitative and quantitative differences were observed, owing to the nature and relative abundance
of different chemical compounds among the wines. 相似文献
22.
Giorgia Oliviero Nicola Borbone Vincenzo Piccialli Gennaro Piccialli Luciano Mayol 《Tetrahedron》2010,66(10):1931-6144
We report here an efficient solid-phase synthesis of N-1-alkyl-substituted analogues of cyclic inosine-diphosphate-ribose (cIDPR), a mimic of cyclic ADP-ribose (cADPR). Our synthetic strategy makes use of a polystyrene support to which inosine was bonded through a 2′,3′-acetal linkage. Insertion of a ω-hydroxy-polymethylene chain of variable length on N-1, followed by conversion into N-1-alkylinosine-bis-phosphate derivatives and cyclization, allowed to obtain analogues of cIDPR of various ring size. The cyclization step was carried out both in solid-phase and in solution by pyrophosphate bond formation. The effect of the N-1-polymethylene chain length on the cyclization yields as well as the reaction conditions, which led to the solid-phase pyrophosphate bond formation, were thoroughly investigated. 相似文献
23.
Bottaro M Frascarolo P Gosetti F Mazzucco E Gianotti V Polati S Pollici E Piacentini L Pavese G Gennaro MC 《Journal of the American Society for Mass Spectrometry》2008,19(8):1221-1229
The paper studies, with the help of HPLC-DAD-MS/MS technique, the hydrolytic and photoinduced degradation processes that take place in aqueous solutions of tribenuron methyl, both when preserved in the dark and when undergoing solar box irradiation under conditions that simulate sun light. The results indicate that the degradation products formed by hydrolysis alone and by photoirradiation are the same, but kinetics of the hydrolysis reaction is much slower. The degradation products are identified as 2-methoxy-4-methylamino-6-methyl-1,3,5-triazine (P1), methyl 2-aminosulfonylbenzoate (P2), and saccharin (P3) and quantified. Ecotoxicological biotests performed on 0.1 microg L(-1) photoirradiated solutions of the herbicide give a border line toxicity situation comparable to that of the precursor and indicate that the herbicide is characterized by low persistence in the environment, as required. Its degradation, however, does not lead to mineralization but to the formation of products of comparable toxicity. To evaluate the matrix effects, the photodegradation of the herbicide is also studied in the presence of rice paddy waters: the process is slower than in ultrapure water but leads to the same products. Experiments performed for comparison by irradiating ultrapure water solutions with UV lamp (254 nm) show that the degradation process is not only faster with respect to sunlight, but gives a different pathway, without in anyway leading to mineralization. 相似文献
24.
Fabio Gosetti Ugo Chiuminatto Davide Zampieri Eleonora Mazzucco Emilio Marengo Maria Carla Gennaro 《Journal of chromatography. A》2010,1217(20):3427-3434
The study investigates the natural photodegradation pathway of mono-chloroanilines in river waters, with the aim to identify the predominant photoproducts formed. At this purpose a new sensitive on-line SPE HPLC–MS/MS method has been developed with LOQ values equal or lower than the legal threshold concentration levels allowed for mono-chloroanilines in waters. The degradation processes of o-, m- and p-chloroaniline have been investigated subjecting their solutions, prepared both in ultrapure and in river water, to sun light irradiation simulated by a solar box system. The SPE HPLC–MS/MS methodology allowed to evaluate the degradation kinetics, to identify the predominant photodegradation products and to propose the chemical structures. Two photoproducts (aniline and 3-aminophenol), for which standards are available, have also been quantified. 相似文献
25.
Parracino A Gajula GP di Gennaro AK Neves-Petersen MT Rafaelsen J Petersen SB 《Journal of fluorescence》2011,21(2):663-672
Medical interest in nanotechnology originates from a belief that nanoscale therapeutic devices can be constructed and directed
towards its target inside the human body. Such nanodevices can be engineered by coupling superparamagnetic nanoparticle to
biomedically active proteins. We hereby report the immobilization of a PhEst, a S-formylglutathione hydrolase from the psychrophilic
P. haloplanktis TAC125 onto the gold coated surface of modified superparamagnetic core-shell nanoparticles (Fe3O4@Au). The synthesis of the nanoparticles is also reported. S-formylglutathione hydrolases constitute a family of ubiquitous
enzymes which play a key role in formaldehyde detoxification both in prokaryotes and eukaryotes. PhEst was originally annotated
as a putative feruloyl esterase, an enzyme that releases ferulic acid (an antioxidant reactive towards free radicals such
as reactive oxygen species) from polysaccharides esters. Dynamic light scattering, scanning electron microscopy with energy
dispersive X-ray spectroscopy, UV–visible absorption spectroscopy, fluorescence spectroscopy, magnetic separation technique
and enzyme catalytic assay confirmed the chemical composition of the gold covered superparamagnetic nanoparticles, the binding
and activity of the enzyme onto the nanoparticles. Activity data in U/ml confirmed that the immobilized enzyme is approximately
2 times more active than the free enzyme in solution. Such particles can be directed with external magnetic fields for bio-separation
and focused towards a medical target for therapeutical as well as bio-sensor applications. 相似文献
26.
High-resolution electron energy loss spectroscopy has been used to probe phonon dispersion in quasi-freestanding graphene epitaxially grown on Pt(111). Loss spectra clearly show different dispersing features related to both acoustic and optical phonons. The present results have been compared with graphene systems which strongly interact with the substrate, i.e. the nearly-flat monolayer graphene (MLG)/Ni(111) and the corrugated MLG/Ru(0001). We found that the phonon dispersion of graphene/Pt(111) reproduces well the behavior of pristine graphite. This could be taken as an indication of the negligible interaction between the graphene sheet and the underlying Pt substrate. The softening of out-of-plane modes observed for interacting graphene/metal interfaces does not occur for the nearly-free-standing graphene/Pt(111). 相似文献
27.
M. Brai M. P. Casaletto G. Gennaro M. Marrale T. Schillaci L. Tranchina 《Applied Physics A: Materials Science & Processing》2010,100(3):945-951
In the present work results on the degradation phenomena of stone materials in the Ancient Theatre of Taormina, one of the
most important Greek–Roman monuments of Sicily, are reported. Artificial stone materials in different conservation conditions
were investigated. Samples of salt efflorescences from brick walls and degraded setting mortars were taken from the open gallery
in “summa cavea”. The chemical, physical and structural characterization was performed by means of X-Ray Photoelectron Spectroscopy (XPS),
X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF), both in situ and ex situ. 相似文献
28.
Patrizia Di Gennaro Silvana Bernasconi Fulvia Orsini Erika Corretto Guido Sello 《Tetrahedron: Asymmetry》2010,21(15):1885-1889
The use of two oxidoreductases (an aldoketo reductase from Escherichia coli JM109 and an alcohol dehydrogenase from Lactobacillus brevis) has demonstrated that it is possible to prepare enatiomerically pure diols in a one-pot operation. The reactions were applied to the synthesis of (1R)-1-[3-(hydroxymethyl)phenyl]ethanol and (1S)-1-phenylethane-1,2-diol, using a two-step procedure. The yield is nearly quantitative and the enantiomeric purity is greater than 95%. A third step has been introduced by adding a cell biocatalyst showing dihydrodiol dehydrogenase activity from Pseudomonas fluorescens N3. This allows for the preparation of 3-[(1R)-1-hydroxyethyl]benzoic acid and (2S)-hydroxy(phenyl)ethanoic acid. 相似文献
29.
E Bolzacchini P Di Gennaro G Di Gregorio B Rindone P Falagiani G Mistrello I Sondergaard 《Journal of chromatography. A》1991,542(2):337-344
High-performance ion-exchange chromatography and immunoaffinity chromatography suggest that Par jI, the principal allergenic component of Parietaria judaica pollen, is a very unstable molecule, which tends to fragment in solution. Several fragments were obtained from Par jI and some of them show positivity toward the anti-Par jI monoclonal antibody, suggesting that they retain the entire structure of the allergenic determinant. These fragments could be the target for sequence and conformation studies. 相似文献