1-1-diphenyl-2-picrylhydrazyl and titanium-dioxide

Nano-TiO. With increased barrier properties, NTLDPE packaging quickly formed a relative lower O. These data indicate that the beneficial effects of NTLDPE packaging on postharvest quality and antioxidant capacity of strawberry are probably associated with the promotion of ROS scavenging and related antioxidant enzyme activities, and NTLDPE packaging together with refrigeration storage is a promising method for strawberry fruit preservation. © 2016 Society of Chemical Industry.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Atmosphere; Biphenyl Compounds; Carbon Dioxide; Cold Temperature; Food Packaging; Food Preservation; Food Storage; Fragaria; Fruit; Humans; Hydrogen Peroxide; Nanostructures; Oxygen; Phenols; Picrates; Polyethylene; Refrigeration; Superoxides; Titanium

Numerous sunscreens contain titanium dioxide (TiO(2)) because of its ability to reflect, scatter, and absorb UV radiation, thus preventing sunlight-related skin disorders. Since TiO(2) is well known to generate reactive oxygen species (ROS) under photoexcitation, it is chemically modified when used in sunscreens. In the present study, five modified TiO(2) particles, specifically developed and marketed for sunscreens, were tested using different in vitro models, including cultured human skin fibroblasts (HuDe), to investigate their possible photocatalytic effects following UVA exposure. The results obtained show that the type of modification and crystal form determine their ability to (a) induce photobleaching of the DPPH radical, (b) photodegrade deoxyribose, (c) reduce cell viability, (d) increase/decrease DNA damage, and (e) increase/decrease intracellular ROS. This research concludes that some modified TiO(2) particles still retain photocatalytic activity under the experimental conditions employed, especially those in which the anatase crystal form of TiO(2) is present. The penetration of TiO(2) nanosized particles into the viable epidermis of skin is still under debate; thus, the results presented here contribute to gaining further knowledge on the potential effects of TiO(2) particles at the cellular level, in the worst possible case that they do penetrate.

Topics: Biphenyl Compounds; Cell Survival; Cells, Cultured; DNA Damage; Fibroblasts; Humans; Nanoparticles; Photochemical Processes; Picrates; Sunscreening Agents; Titanium; Ultraviolet Rays

Chinese bayberry is susceptible to microbial decay during postharvest handling and storage. To search for effective alternatives to currently used fungicides for disease control, the efficacy of hot air (HA) treatment at 48 °C for 3 h alone or in combination with nano-packing (NP) containing nano-TiO(2) and nano-Ag in controlling green mould decay caused by Penicillium citrinum and natural decay, and their effects on fruit quality in harvested Chinese bayberries were investigated in this study.. The combined treatment of HA and NP resulted in a remarkably improved control of green mould and natural decay in Chinese bayberries compared with treatment of HA or NP alone. The in vitro growth of P. citrinum was significantly inhibited by individual HA or NP. In addition, HA in combination with NP showed interactive effect on inhibiting fruit respiration, ethylene production and membrane lipid peroxidation, and maintained higher fruit firmness and DPPH radical scavenging activity.. These results suggest that a combination of HA treatment and NP may be a useful technique to reduce fruit decay and maintain quality in Chinese bayberries during postharvest storage and retail conditions.

Topics: Air; Antioxidants; Biphenyl Compounds; Cell Membrane; Cell Respiration; Ethylenes; Food Microbiology; Food Packaging; Food Preservation; Fruit; Fungicides, Industrial; Hot Temperature; Lipid Peroxidation; Mercury; Myrica; Nanoparticles; Penicillium; Picrates; Plants; Titanium

The use of nanostructured TiO(2) as mixed phase photocatalyst in the synthesis of 2H-pyrano/2H-thiopyrano [2,3-b]quinoline-2-carboxylic acid (2a/2b) is described. The binding modes of 2a/2b with ds DNA fragments d(CGCGAATTCGCG) were predicted by molecular docking studies. The lowest energy was found in the compound 2b with a binding energy of -7.44 Kcal/mol and inhibition constant of 5.39 x e(-6). The interaction study with CT DNA was carried out by absorption spectra, (K(b) constant obtained for 2a is 3.5x10(6) and for 2b it is 2.9x10(5)), viscosity and thermal denaturation methods. The in vitro antioxidant activities were evaluated. Finally, the results showed that the intercalated 2a/2b compounds are strong antioxidants and they protect oxidative DNA damage from harmful free radicals.

Topics: Antioxidants; Biphenyl Compounds; DNA; Free Radical Scavengers; Hydrogen Peroxide; Hydroxyl Radical; Microwaves; Models, Molecular; Molecular Structure; Nanostructures; Nucleic Acid Denaturation; Oxidation-Reduction; Picrates; Quinolines; Spectrophotometry; Superoxides; Titanium; Transition Temperature; Viscosity

A new method of measuring photoactivity of a major group of inorganic sunscreens (coated titanium dioxide) is presented based on the photobleaching of the radical 1,1-diphenyl-2-picrylhydrazyl.

Topics: Bepridil; Biphenyl Compounds; Colorimetry; Free Radicals; Kinetics; Light; Picrates; Titanium; Ultraviolet Rays