Xanthene

About: Xanthene is a research topic. Over the lifetime, 2132 publications have been published within this topic receiving 34803 citations. The topic is also known as: Xanthene & dibenzo[a,e]pyran.

The reaction mechanism of the acid‐catalysed autoxidation of xanthene to xanthylium ion

Abstract: This paper describes an investigation into the kinetics of the autoxidation of xanthene to xanthylium ion and hydrogen peroxide in a perchloric acid/acetic acid mixture at 20°. Apart from acid catalysis, the reaction also shows the characteristics of a free-radical chain autoxidation. In the mechanism devised to account for the results the key feature is hydrogen abstraction by a protonated peroxy radical with simultaneous production of the stable xanthylium ion:

Stabilized organic compound

Abstract: PURPOSE:To obtain an org. compd. which does not cause deterioration by oxidation even when exposed to a high-temperature atmosphere, by adding a specified xanthene compd. and a light stabilizer to an org. compd. CONSTITUTION:0.01-10pts.wt. light stabilizer and 0.001-10pts.wt. compd. of the formula (wherein R1-R9 are each H, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, acyloxy, hydroxyl, hologen, amino, nitro; R is H, alkyl, cycloalkyl, aryl, aralkyl, hydroxyl, halogen, carboxyl, carboalkoxy) are blended with 100pts.wt. org. compd. Examples of the compds. of the formula are 2,7-dimethylxanthene, 9- benzylxanthene, etc.

The Influence of Halogen Derivatives of Thyronine and Fluorescein on the Dipole Potential of Phospholipid Membranes

Abstract: The effects of halogen derivatives of thyronine (tetraiodotironine and triiodothyronine) and fluorescein (Rose Bengal, phloxine B, erythrosin, eosin Y, and fluorescein) on the dipole potential of membranes composed of diphytanoylphosphocholine, diphytanoylphosphoserine, and diphytanoylphosphoethanolamine were investigated. A quantitative description of the modifying action of the agents was presented as characteristic parameters of the Langmuir adsorption isotherm: the maximum changes in the dipole potential of the membrane at an infinitely high concentration of modifiers and the desorption constant, characterizing their inverse affinities to the lipid phase. It was shown that the iodine-containing hormones led to a less significant reduction in the dipole potential of phospholipid membranes compared to the xanthene dyes, Rose Bengal, phloxine B, and erythrosin. The latter were characterized by the highest affinity for the lipid membranes compared to tetraiodotironine and triiodothyronine. It was found that the effect of iodine-containing hormones and xanthene dyes on the membrane dipole potential was caused by their uncharged and charged forms, respectively.