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.

Synthesis, DNA-binding study, and antioxidant activity of 14-aryl-14H-dibenzo[a,j]xanthene derivatives

Abstract: A simple and efficient one-pot method for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives using Ni(ClO4)2·6H2O as a catalyst is described. DNA-binding properties of 14-aryl-14H-dibenzo[a,j]xanthene derivatives 1a, 1j, 1l, 1m, and 1n were investigated using calf thymus DNA by electronic absorption spectroscopy and fluorescence spectroscopy. Binding constant (K b) with DNA was calculated from the absorption measurements. The spectral changes observed such as hypochromicity, red shift, and isosbestic point are consistent with the intercalation mode of binding of the chromophore into the stack DNA base pairs. Among the five, compound 1n with strong electron donating substituents on the phenyl ring shows better intercalative binding with DNA. Investigations of antioxidant properties show that the dibenzo[a,j]xanthene 1m with –OH group substitution has high radical scavenging properties against DPPH and ABTS+.

Xanthene-based pigment and ink jet recording liquid containing the same pigment

Abstract: PROBLEM TO BE SOLVED: To obtain a new xanthene-based pigment excellent in light resistance of color image, excellent in color tone of good color reproducibility and especially excellent in light resistance and color tone of magenta color and useful for ink jet recording liquid. SOLUTION: This compound is represented by formula I [R 1 and R 2 are each H or a ≥2C alkyl; Ph 1 and Ph 2 are each phenyl having at least one branched alkyl at ortho position; Y 1 and Y 2 are each sulfo or a halogen; Z is Y 1 , carboxyl, sulfamoyl, etc.; An -1 represents a pair ion, but when there a pair ion exists in the molecule, An -1 is unnecessary; (l) and (m) are each 0-2; (n) is 1-5], e.g. sodium 3-isopropyl-4-{[9-(2-carboxylphenyl)-6-(2- isopropylphenylamino)-3H-xanthene-3,3-diyl]amino}benzenesulfonate. The exemplified compound is obtained by reacting a compound of formula III with 0- isopropylaniline, sulfonating the resultant compound and treating the sulfonated compound with caustic soda. COPYRIGHT: (C)1997,JPO

Photodynamic inactivation of sarcoplasmic reticulum vesicle membranes by xanthene dyes.

Abstract: — Photosensitized oxidation of sarcoplasmic reticulum (SR) vesicle membranes by a series of xanthene dyes was investigated. With increasing dye concentration and illumination time, the calcium ion uptake, ATPase activity and UV fluorescence intensity of SR decreased, and the absorbance at 241 nm increased. In xanthene dyes, the order of inactivation of the calcium uptake and ATPase activity of SR was in accord with decreasing order, of fluorescence intensity and increasing order of absorbance at 241 nm. Some regular relationships exist between the molecular structures of xanthene dyes and the photodynamic inactivation of SR membranes.

Efficient one-pot syntheses of dibenzo(a,i) xanthene-diones and evaluation of their antioxidant activity

Abstract: Facile and convenient procedures for the synthesis of dibenzo[a,i]xanthene-diones have been described. The process employs one-pot condensation of aldehydes, 2-hydroxynaphthalene-1,4-dione, and 2-n...