Search results for "Aldehydes"
showing 10 items of 86 documents
Sunlight-induced reactions of some heterocyclic bases with ethers in the presence of TiO2. A green route for the synthesis of heterocyclic aldehydes
2005
Aldehydes measurements in public indoor environments in Palermo (Italy) using voltammetry.
2012
Studies on indoor air quality are important since people spend more than 80% of life in confined environments, thus it is necessary to evaluate indoor contaminant concentrations and distributions for assessing total human exposure to them (Mannino and Orecchio, 2008; Orecchio, 2011). Aldehydes are indoor and outdoor chemical pollutants of particular interest due to their potential impact on health. Formaldehyde is usually the most abundant aldehyde in air and also the most studied since it is classified as human carcinogen. It is well known that formaldehyde is directly emitted from building materials, wood combustion, cigarette smoking, and is used as a bactericidal agent. One purpose of t…
Photocatalytic process intensification by coupling with pervaporation
2011
The integration of photocatalysis with a membrane separation process, in particular pervaporation, permits the recovery of valuable intermediate compounds (aromatic aldehydes) while they are produced avoiding their further degradation in the reactive ambient. In this way the yield and the conversion are enhanced. The coupling of the two processes is straightforward and the integration is complete even maintaining pervaporation and photocatalysis in two separate apparatuses provided that the process stream is continuously recycled at a sufficiently high flow rate. Additional advantages are: higher degree of purification of the aldehyde in the powder-free product stream, semicontinuous produc…
Control of N-Heterocyclic Carbene Catalyzed Reactions of Enals: Asymmetric Synthesis of Oxindole-γ-Amino Acid Derivatives.
2017
A strategy to control the switch between a non‐cycloaddition reaction and a cycloaddition reaction of enals, using N‐heterocyclic carbene (NHC) catalyisis, has been developed. The new scalable protocol leads to γ‐amino‐acid esters bearing a tetrasubstituted stereocenter in good yields and high stereoselectivities by homo‐Mannich reactions of enals and isatin‐derived ketimines. By simply changing the N‐ketimine substituent to an ortho‐hydroxy phenyl group, the corresponding spirocyclic oxindolo‐γ‐lactams are obtained. peerReviewed
Green Oxidation of Alcohols to Carbonyl Compounds by Heterogeneous Photocatalysis
2010
An inter-laboratory validation of methods of lipid peroxidation measurement in UVA-treated human plasma samples
2010
Lipid peroxidation products like malondialdehyde, 4-hydroxynonenal and F2-isoprostanes are widely used as markers of oxidative stress in vitro and in vivo. This study reports the results of a multi-laboratory validation study by COST Action B35 to assess inter-laboratory and intra-laboratory variation in the measurement of lipid peroxidation. Human plasma samples were exposed to UVA irradiation at different doses (0, 15 J, 20 J), encoded and shipped to 15 laboratories, where analyses of malondialdehyde, 4-hydroxynonenal and isoprostanes were conducted. The results demonstrate a low within-day-variation and a good correlation of results observed on two different days. However, high coefficie…
alpha-Tocopherol, MDA-HNE and 8-OHdG levels in liver and heart mitochondria of adriamycin-treated rats fed with alcohol-free beer.
2008
Different studies indicate that oxidative stress and mitochondrial damage are key factors in different pathogenic process. The aim of this study was to investigate the possible protective role of alcohol-free beer on adriamycin-induced (ADR) heart and liver toxicity using biomarkers of oxidative stress. This effect was compared with the effect of alcohol beer intake and with a control group. Rats were randomly divided into six groups. The first group received no adriamycin, was fed with water and was regarded as the control group; the second group was injected with a ADR (two cycles of 5mg/kg); the third and fourth groups were fed with alcohol-free and beer for 21 days, respectively and the…
A Comprehensive Review on Lipid Oxidation in Meat and Meat Products.
2019
Meat and meat products are a fundamental part of the human diet. The protein and vitamin content, as well as essential fatty acids, gives them an appropriate composition to complete the nutritional requirements. However, meat constituents are susceptible to degradation processes. Among them, the most important, after microbial deterioration, are oxidative processes, which affect lipids, pigments, proteins and vitamins. During these reactions a sensory degradation of the product occurs, causing consumer rejection. In addition, there is a nutritional loss that leads to the formation of toxic substances, so the control of oxidative processes is of vital importance for the meat industry. Noneth…
When the nose must remain responsive: glutathione conjugation of the mammary pheromone in the newborn rabbit
2014
In insects, xenobiotic-metabolizing enzymes were demonstrated to regulate pheromones inactivation, clearing them from the olfactory periphery and keeping receptors ready for stimulation renewal. Here, we investigate whether similar processes could occur in mammals, focusing on the pheromonal communication between female rabbits and their newborns. Lactating rabbits emit in their milk a volatile aldehyde, 2-methylbut-2-enal, that elicits searching-grasping in neonates; called the mammary pheromone (MP), it is critical for pups which are constrained to find nipples within the 5 min of daily nursing. For newborns, it is thus essential to remain sensitive to this odorant during the whole nursin…
Preparation of ferulic acid derivatives and evaluation of their xanthine oxidase inhibition activity.
2007
Several ferulic acid ethyl esters (3a-h) were synthesized under the Knoevengel reaction condition and they were further reduced to afford the respective allylic alcohol derivatives (4a-g). Some of them were evaluated for the xanthine oxidase (XO) inhibitory activity. Among them, 3h exhibited a significant inhibitory activity with an IC50 value of 1.35 x 10(-5) M, while the IC50 value of allopurinol used as the positive control was 1.49 x 10(-5) M. The study suggested that the higher acidity of the phenolic OH group in the ferulic acid derivatives might result in improved XO inhibitory activity.