ABSTRACT
Chlorogenic (CA) and rosmarinic (RA) acids are two natural bioactive hydroxycinnamic acids whose antioxidant properties can be modulated by the chelation of metal ions. In this work, the interactions of these two carboxylic phenols with calcium ions and the impact of such interactions on their antioxidant activity were investigated. UV-Vis absorbance, mass spectroscopy and 1H and 13C liquid NMR were used to identify complexes formed by CA and RA with calcium. Antioxidant activities were measured by the Bois method. Density functional theory (DFT) calculations were performed to evaluate the most stable configurations and correlated with NMR data. Taken together, these data suggest that calcium ions mainly interact with the carboxylate groups of both molecules but that this interaction modifies the reactivity of the catechol groups, especially for RA. These results highlight the complex interplay between metal chelation and antioxidant properties of natural carboxylic phenols.
Subject(s)
Antioxidants/chemistry , Calcium/chemistry , Chelating Agents/chemistry , Chlorogenic Acid/chemistry , Cinnamates/chemistry , Depsides/chemistry , Biphenyl Compounds/radiation effects , Density Functional Theory , Drug Interactions , Models, Molecular , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Photobleaching , Picrates/radiation effects , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Ultraviolet , Rosmarinic AcidABSTRACT
BACKGROUND: Berries are known for their antioxidant activity due to the presence of flavonoids. Antioxidants' usage guarantees skin protection against free radicals and, flavonoids, especially, can act as sunscreen. The aim of this paper was to evaluate solar protection factor (SPF) and antioxidant activity in vitro of blackberry and raspberry extracts incorporated in topical formulation and study their stability. RESULTS: Raspberry presented 29.93 mg of anthocyanins/100 g of fruit and blackberry 65.58 mg of anthocyanins/100 g of fruit. In vitro solar protection factor was 54.57 to blackberry and 37.32 to raspberry. When incorporated in O/W emulsions, final formulations showed light pink color, creamy aspect, and typical fruity odor. Formulations submitted to indirect light and stove showed odor and color alterations. CONCLUSIONS: Based on the results, formulations containing extracts should be kept under refrigeration in opaque package to ensure stability due to the presence of flavonoids. In addition, blackberry and raspberry extracts are potential natural alternatives to be used as sunscreen and to prevent skin aging.
Subject(s)
Anthocyanins/chemistry , Antioxidants/chemistry , Plant Extracts/chemistry , Rubus/chemistry , Sunscreening Agents/chemistry , Anthocyanins/isolation & purification , Antioxidants/isolation & purification , Biphenyl Compounds/chemistry , Biphenyl Compounds/radiation effects , Drug Stability , Drug Storage , Fruit/chemistry , Humans , Oxidation-Reduction/radiation effects , Picrates/chemistry , Picrates/radiation effects , Plant Extracts/isolation & purification , Quercetin/chemistry , Quercetin/radiation effects , Spectrophotometry , Sun Protection Factor , Sunscreening Agents/isolation & purification , Ultraviolet RaysABSTRACT
Calcium oxide (CaO) nanoparticles are known to exhibit unique property due to their high adsorption capacity and good catalytic activity. In this work the CaO nanocatalysts were prepared by hydrothermal method using anionic surfactant, sodium dodecyl sulphate (SDS), as a templating agent. The as-synthesized nanocatalysts were further used as substrate for the synthesis of alumina doped calcium oxide (Al2O3·CaO) nanocatalysts via deposition-precipitation method at the isoelectric point of CaO. The Al2O3·CaO nanocatalysts were characterized by FTIR, XRD, TGA, TEM, and FESEM techniques. The catalytic efficiencies of these nanocatalysts were studied for the photodegradation of 2,4,6-trinitrophenol (2,4,6-TNP), which is an industrial pollutant, spectrophotometrically. The effect of surfactant and temperature on size of nanocatalysts was also studied. The smallest particle size and highest percentage of degradation were observed at critical micelle concentration of the surfactant. The direct optical band gap of the Al2O3·CaO nanocatalyst was found as 3.3 eV.
Subject(s)
Aluminum Oxide/chemistry , Calcium Compounds/chemistry , Oxides/chemistry , Picrates/chemistry , Picrates/isolation & purification , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Adsorption/radiation effects , Aluminum Oxide/radiation effects , Calcium Compounds/radiation effects , Catalysis , Light , Micelles , Oxides/radiation effects , Picrates/radiation effects , Sodium Dodecyl Sulfate/chemistry , Sodium Dodecyl Sulfate/radiation effects , Water/chemistry , Water Pollutants, Chemical/radiation effectsABSTRACT
Comparison was observed for degradation and mineralization of the explosive 2,4,6-trinitroresorcine (TNR) in different photochemical systems TNR/UV, TNR/UV/TiO2, TNR/UV/H2O2, TNR/UV/O3, TNR/UV/TiO2/H2O2 and TNR/UV/TiO2/O3 using High Performance Liquid Chromatography coupled with Mass Spectrometry (HPLC/MS) and Total Organic Carbon (TOC) analysis. Addition of oxidizing agents such as H2O2 or O3 accelerated the rate of TNR conversion and mineralization. Highest reaction rate was obtained in TNR/UV/TiO2/H2O2 system. The intermediate products were characterized and identified by LS-MS technique. The similarity in intermediate products of TNR suggested the analogous reaction pathways of the TNR degradation by these different systems.
Subject(s)
Minerals/chemistry , Photochemistry , Picrates/chemistry , Picrates/radiation effects , Resorcinols/chemistry , Resorcinols/radiation effects , Catalysis/radiation effects , Chromatography, High Pressure Liquid , Hydrogen Peroxide/chemistry , Hydrogen-Ion Concentration/radiation effects , Mass Spectrometry , Oxygen/chemistry , Solutions , Time Factors , Titanium/chemistry , Ultraviolet Rays , Water/chemistryABSTRACT
Silymarin, a purified extract of seeds of Silybum marianum L. and well known for its hepatoprotective abilities, has been evaluated for inherent utility as a radioprotective agent. A fraction (INM-7035) was authenticated by characterizing the percentage composition of silybin A and B (39.9% and 57.4%). Free radical scavenging activities of INM-7035 against superoxide radicals (>68%), hydroxyl radicals (>33.75%), DPPH (67.2%), and ABTS (32.4%) were also evaluated. The fraction chelated (>30%) ferrous ions, thereby able to restrict amplification. INM-7035 exhibited >50% peroxyl radical scavenging activity in the lipid phase along with dose-dependent (R2 = 0.990) reducing power in the aqueous phase. Radiation-induced free radical flux can lead to disruption of biomolecules like membrane lipids. INM-7035 completely inhibited lipid peroxidative stress in case of membranes against supralethal radiation stress in the liposomal system. The ability of INM-7035 to modulate the levels of NF-kappaB, indicated its inherent potential as a radioprotective bioactive constituent.
