Search results for "xanthone"
showing 10 items of 28 documents
Comprehensive analysis of photoinitiators and primary aromatic amines in food contact materials using liquid chromatography High-Resolution Mass Spec…
2018
Abstract A comprehensive strategy for the analysis of UV-ink photoinitiators and primary aromatic amines (PAAS) in food-packaging materials such as, juice tetrabricks, pouches and bags has been developed using liquid chromatography coupled to Orbitrap High-Resolution Mass Spectrometry (LC-Orbitrap-HRMS). The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous optimisation of the single-stage Orbitrap fragmentation through the Higher-Energy Collisional Dissociation (HCD) Cell. Overall, the quantitative method presented recoveries ranging from 78% to 119%, with a precision (RSD) lower than 20%, f…
Principes généraux d'évaluation/gestion du risque des matériaux au contact des denrées alimentaires
2017
International audience; Les matériaux au contact des denrées alimentaires (MCDA) jouent un rôle incontournable en matière de conservation et de protection des aliments. Cependant, des substances de l'emballage (monomères, additifs) peuvent migrer dans les aliments. Ainsi, pour être aptes au contact alimentaire, les MCDA ne doivent pas libérer des substances en une quantité qui pourrait mettre en danger la santé humaine ou modifier les caractères organoleptiques et la composition des aliments : c'est le principe d'inertie du Règlement no 1935/2004 du Parlement européen et du Conseil sur les MCDA. De plus, une réglementation harmonisée au niveau européen existe pour certains matériaux (cas de…
A butterfly like motion as a clue to the photophysics of thioxanthone
2006
Abstract A theoretical, quantum-chemical study of the thioxanthone (TX) molecule has been performed at the MP2 and CASPT2 levels of theory. Geometries, absorption energies, and transition and state properties have been investigated. Two conformers have been found very close in energy with planar (P) and non-planar (NP) structures, the latter characterized by a dihedral angle θ = 173.3° representing the bend of the side benzene rings and an out-of-plane angle ϕ = 4° of the C O bond. Large changes in the relative positions and properties of the two low-lying electronic absorption bands, ππ * and nπ * , are computed when changing the conformation. As a consequence of the analysis of the TX a…
Innovative strategies to treat skin wounds with mangiferin: fabrication of transferosomes modified with glycols and mucin
2020
Aim: The moisturizing properties of glycerol, the penetration enhancing capability of propylene glycol and the bioadhesive properties of mucin were combined to improve the carrier capabilities of transfersomes and the efficacy of mangiferin in the treatment of skin lesions. Materials & methods: Mangiferin was incorporated in transfersomes and glycoltransfersomes, which were also modified with mucin. The physico–chemical features were assessed, along with the efficacy against oxidative stress and skin wounds in vitro and in vivo. Results: Glycoltransfersomes promoted the deposition of mangiferin in epidermis and dermis, protected fibroblasts from oxidative stress and stimulated their pr…
Biphenyls and xanthones from the podostemaceae
1992
Abstract Investigation of the fruiting parts of Mourera fluviatilis afforded 6-desoxyjacareubin, trapezifoliaxanthone and a series of eight new biphenyl derivatives; 3,5-dimethoxybiphenyl; 2,2-dimethyl-5-methoxy-7-phenylchromene; 2,2-dimethyl-7-methoxy-5-phenylchromene; 2-(3,3-dimethylallyl)-3-hydroxy-5-methoxybiphenyl; 2,3-dihydro-6-methoxy-4-phenyl-2,3,3-trimethylcoumarone; [(2,3-dihydro-3,3-dimethyl-6-methoxy-4-phenyl)-2-coumaronyl]methanol; 2,3-dihydro-3,3-dimethyl-6-methoxy-2-oxo-4-phenylcoumarone; and a dimeric biphenyl.
Antioxidant treatment for impaired hypoxic ventilatory responses in experimental diabetes in the rat
2018
Inflammation, tissue hypoxia, and impaired hypoxic ventilatory response (HVR) are the intricately entwined features of diabetes which perpetuate the disease and its sequelae. Hyperglycemia, notably, is an oxygen consuming process due to enhanced cellular metabolism. Oxidative stress underlies diabetic pathogenesis and also is a crucial modulator of the hypoxic chemoreflex. The present study seeks to determine if suppressed ventilation in diabetes could be improved by antioxidant treatment. The study was performed in streptozotocin-induced diabetes in awake rats. Two weeks into full-fledged diabetes, the rats were divided into mangiferin (potent natural antioxidant)-treated and untreated, wi…
Multiparametric evaluation of the cytoprotective effect of the Mangifera indica L. stem bark extract and mangiferin in HepG2 cells.
2012
Abstract Objective Mango (Mangifera indica L.) stem bark extract (MSBE) is a natural product with biological properties and mangiferin is the major component. This paper reported the evaluation of the protective effects of MSBE and mangiferin against the toxicity induced in HepG2 cells by tert-butyl hydroperoxide or amiodarone. Method Nuclear morphology, cell viability, intracellular calcium concentration and reactive oxygen species (ROS) production were measured by using a high-content screening multiparametric assay. Key findings MSBE and mangiferin produced no toxicity below 500 mg/ml doses. A marked recovery in cell viability, which was reduced by the toxicants, was observed in cells pr…
Comparative HPLC/ESI-MS and HPLC/DAD study of different populations of cultivated, wild and commercial Gentiana lutea L.
2015
The root of Gentiana lutea L., famous for its bitter properties, is often used in alcoholic bitter beverages, food products and traditional medicine to stimulate the appetite and improve digestion. This study presents a new, fast, and accurate HPLC method using HPLC/ESI-MS and HPLC/DAD for simultaneous analysis of iridoids (loganic acid), secoiridoids (gentiopicroside, sweroside, swertiamarin, amarogentin) and xanthones (isogentisin) in different populations of G.lutea L., cultivated in the Monti Sibillini National Park, obtained wild there, or purchased commercially. Comparison of HPLC/ESI-MS and HPLC/DAD indicated that HPLC/ESI-MS is more sensitive, reliable and selective. Analysis of twe…
Synthesis of novel xanthone and acridone carboxamides with potent antiproliferative activities
2020
Abstract Several new amino-substituted acridone and xanthone derivatives have been designed and synthesized, using an efficient methodology from suitable acridone- or xanthone-carboxylic acid intermediates. The antiproliferative activity of the target compounds has been evaluated against four cancer cell lines, namely breast adenocarcinoma MCF-7, acute lymphocytic leukemia CCRF-CEM, and its doxorubicin-resistant variant CEM/ADR5000 and prostate cancer PC-3 cell lines. Selected derivatives have also been tested against the urinary bladder T24 and metastatic melanoma WM266-4 cancer cell lines. Two nitro substituted acridones, bearing a basic side chain as well, were endowed with a remarkable …
Mangiferin glycethosomes as a new potential adjuvant for the treatment of psoriasis
2020
[EN] Mangiferin, a natural compound isolated from Mangifera indica L, was incorporated in glycerosomes, ethosomes and alternatively in glycerol-ethanol phospholipid vesicles (glycethosomes). Actually, only glycethosomes were able to stably incorporate the mangiferin that was loaded at increasing concentrations (2, 4, 6, 8 mg/mL). The morphology, size distribution, rheological properties, surface charge and entrapment efficiency of prepared vesicles were deeply measured. All vesicles were mainly spherical, oligolamellar, small in size (similar to 145 nm) and negatively charged (similar to-40 mV), as confirmed by cryo-TEM observation and dynamic laser light scattering measurements. The higher…