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101.
Jerkovic V Nguyen F Nizet S Collin S 《Rapid communications in mass spectrometry : RCM》2007,21(15):2456-2466
Analyses of methoxylated and glycosylated stilbenes remain scarce in the literature because of the commercial unavailability of these compounds. Here a library of 22 compounds was synthesized by combinatorial chemistry. Their elution profiles were compared on three different columns (C18, C8, and silica) with those of seven commercial resveratrol analogues and two viniferins. The spectra recorded by liquid chromatography/positive atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI(+)-MS/MS) are discussed and recommendations made for easier identification of new stilbenes. 相似文献
102.
Stefania?Gaudino Chiara?Galas Maria?Belli Sabrina?Barbizzi Paolo?de?Zorzi Radojko?Ja?imovi? Zvonka?Jeran Alessandra?Pati Umberto?SansoneEmail author 《Accreditation and quality assurance》2007,12(2):84-93
The measurement of trace-element concentration in soil, sediment and waste, is generally a combination of a digestion procedure
for dissolution of elements and a subsequent measurement of the dissolved elements. “Partial” and “total” digestion methods
can be used in environmental monitoring activities. To compare measurement results obtained by different methods, it is crucial
to determine and to maintain control of the bias of the results obtained by these methods. In this paper, ICP-MS results obtained
after matrix digestion with modified aqua regia (HCl+HNO3+H2O2) method and two “total” digestion methods (microwave aqua regia+HF and HNO3+HF) are compared with those obtained by instrumental neutron activation analysis, a non-destructive analytical method for
the determination of the total mass concentrations of inorganic components in environmental matrices. The comparison was carried
out on eight agricultural soil samples collected in one test area and measured by k0-INAA and ICP-MS to determine As, Co, Cr, Sb and Zn mass concentration. The bias of results for As, Cd, Co, Cr, Cu, Ni, Pb,
Sb and Zn of the three digestion methods were assessed using selected measurement standards. This paper highlights that the
digestion procedure is an integral part of the measurement and can affect the measurement result in environmental analysis. 相似文献
103.
Nicola Zerbinati Sabrina Sommatis Cristina Maccario Serena Di Francesco Maria Chiara Capillo Giulia Grimaldi Raffaele Rauso Martha Herrera Pier Luca Bencini Roberto Mocchi 《Molecules (Basel, Switzerland)》2021,26(24)
(1) Background: Cosmeceuticals are topical products applied to human skin to prevent skin ageing and maintain a healthy skin appearance. Their effectiveness is closely linked to the compounds present in a final formulation. In this article, we propose a panel of in vitro tests to support the efficacy assessment of an anti-ageing cream enriched with functional compounds. (2) Methods: biocompatibility and the irritant effect were evaluated on reconstructed human epidermis (RHE) and corneal epithelium (HCE) 3D models. After a preliminary MTT assay, normal human dermal fibroblasts (NHDF) and keratinocytes (HaCaT) were used to evaluate the extracellular matrix (ECM) protein synthesis, and interleukin-6 (IL-6) and metalloproteinase-1 (MMP-1) production. (3) Results: data collected showed good biocompatibility and demonstrated the absence of the irritant effect in both 3D models. Therefore, we demonstrated a statistical increase in collagen and elastin productions in NHDF cells. In HaCaT cells, we highlighted an anti-inflammatory effect through a reduction in IL-6 levels in inflammatory stimulated conditions. Moreover, the reduction of MMP-1 production after UV-B radiation was demonstrated, showing significant photo-protection. (4) Conclusion: a multiple in vitro assays approach is proposed for the valid and practical assessment of the anti-ageing protection, anti-inflammatory and biocompatible claims that can be assigned to a cosmetic product containing functional compounds. 相似文献
104.
105.
Fabio Ferrini Daniele Fraternale Sabrina Donati Zeppa Giancarlo Verardo Andrea Gorassini Vittoria Carrabs Maria Cristina Albertini Piero Sestili 《Molecules (Basel, Switzerland)》2021,26(16)
Cannabis sativa L. has been used for a long time to obtain food, fiber, and as a medicinal and psychoactive plant. Today, the nutraceutical potential of C. sativa is being increasingly reappraised; however, C. sativa roots remain poorly studied, despite citations in the scientific literature. In this direction, we identified and quantified the presence of valuable bioactives (namely, β-sitosterol, stigmasterol, campesterol, friedelin, and epi-friedelanol) in the root extracts of C. sativa, a finding which might pave the way to the exploitation of the therapeutic potential of all parts of the C. sativa plant. To facilitate root harvesting and processing, aeroponic (AP) and aeroponic-elicited cultures (AEP) were established and compared to soil-cultivated plants (SP). Interestingly, considerably increased plant growth—particularly of the roots—and a significant increase (up to 20-fold in the case of β-sitosterol) in the total content of the aforementioned roots’ bioactive molecules were observed in AP and AEP. In conclusion, aeroponics, an easy, standardized, contaminant-free cultivation technique, facilitates the harvesting/processing of roots along with a greater production of their secondary bioactive metabolites, which could be utilized in the formulation of health-promoting and health-care products. 相似文献
106.
107.
Sabrina Castellano Marisabella Santoriello Pietro Campiglia Giovanna Cardillo Alessia Bertamino Isabel Gomez-Monterrey Ettore Novellino Gianluca Sbardella 《Tetrahedron letters》2009,50(49):6869-6871
An inexpensive and regioselective approach to dihydrothieno[3,2-g]quinoline-4,9-dione is reported. A combination of a mild version of Skraup reaction with a sequential substitution/Michael addition allowed the selective preparation in acceptable yield of a pharmacologically important quinone derivative, previously obtained only in trace and together with the other regioisomer. 相似文献
108.
Aliphatic polyesters have acquired significant interest as environmentally friendly thermoplastics for a wide range of applications, and understanding their degradation behaviour has relevance both for processing and end uses. We have investigated the thermal and thermo-oxidative degradation processes occurring in synthetic and commercial poly(butylene succinate) (PBSu). Thermal oxidation was performed in atmospheric air using extremely thin polymer films at 170 °C for up to 6 h. The oxidized compounds were analyzed by size exclusion chromatography (SEC), NMR spectroscopy, and Mass Spectrometry (MALDI-TOF MS). A measurable reduction of the molar mass of the polyesters was soon apparent, promoting the formation of PBSu oligomers with different end groups. MALDI mass spectrometry combined with the use of extremely thin polyester films provided a virtual magnifying glass to obtain exhaustive information on the structure of the oxidation products. An α-H abstraction mechanism has been unambiguously ascertained to be the primary step in PBSu oxidation. The oxidized polymer chains originating from the decomposition of the hydroperoxide intermediate by radical rearrangement reactions had not been revealed before. The latter products subsequently undergo chain scission processes, which can be accurately traced from the chemical species identified in our work. Thermal degradation experiments were also performed under nitrogen at 240-260 °C. The new species identified in the MALDI spectra support a decomposition pathway taking place through a β-hydrogen-transfer mechanism, followed by the production of succinic anhydride from succinic acid end molecules via a back-biting process. 相似文献
109.
Giulio Scocchi Dr. Paola Posocco Jan‐Willem Handgraaf Dr. Johannes G. E. M. Fraaije Prof. Maurizio Fermeglia Prof. Sabrina Pricl Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(31):7586-7592
We present an innovative, multiscale computational approach to probe the behaviour of polymer–clay nanocomposites (PCNs). Our modeling recipe is based on 1) quantum/force‐field‐based atomistic simulation to derive interaction energies among all system components; 2) mapping of these values onto mesoscopic bead–field (MBF) hybrid‐method parameters; 3) mesoscopic simulations to determine system density distributions and morphologies (i.e., intercalated versus exfoliated); and 4) simulations at finite‐element levels to calculate the relative macroscopic properties. The entire computational procedure has been applied to two well‐known PCN systems, namely Nylon 6/Cloisite 20A and Nylon 6/Cloisite 30B, as test materials, and their mechanical properties were predicted in excellent agreement with the available experimental data. Importantly, our methodology is a truly bottom‐up approach, and no “learning from experiment” was needed in any step of the entire procedure. 相似文献
110.
Christman KL Requa MV Enriquez-Rios VD Ward SC Bradley KA Turner KL Maynard HD 《Langmuir : the ACS journal of surfaces and colloids》2006,22(17):7444-7450
Micron and submicron-scale features of aldehyde functionality were fabricated in polymer films by photolithography to develop a platform for protein immobilization and assembly at a biologically relevant scale. Films containing the pH-reactive polymer poly(3,3'-diethoxypropyl methacrylate) and a photoacid generator (PAG) were patterned from 500 nm to 40 mum by exposure to 365 nm (i-line) light. Upon PAG activation and hydrolysis of acetals, aldehyde groups formed. After the films were incubated with a biotinylated aldehyde reactive probe, the X-ray photoelectron spectroscopy results were consistent with biotin being attached to the surface. The background was subsequently passivated by flood exposure and incubation with an aminooxy-terminated poly(ethylene glycol), resulting in a 98% reduction in nonspecific protein adsorption. Protein patterning and assembly was demonstrated using streptavidin, biotinylated anthrax toxin receptor-1, and the protective antigen moiety of anthrax toxin and confirmed by fluorescence microscopy and atomic force microscopy (AFM). AFM demonstrated that 500 nm protein features were achieved. Because of the abundance of biotinylated proteins, this methodology provides a platform for protein immobilization and assembly for various applications in biotechnology. 相似文献