The extra-weak chemiluminescence generated during oxidation of some tetracycline antibiotics 1. Autoxidation

Abstract

Chemiluminescence (CL) appearing during autoxidation of tetracycline (TC) antibiotics has been studied. The CL spectrum consists of four emission bands with maxima at 520, 585, 640 and 700 nm. The bands at 585, 640 and 700 nm are similar to those observed for singlet molecular oxygen (1O2). The effect of 1O2 quenchers and free radical reaction inhibitors on the light emission is also reported. The data support the concept that, during the autoxidation of TCs, cytotoxic oxygen species such as HO., O2.-, H2O2 and 1O2 are formed.

Potential Iatrogenic Tetracycline Staining of Endodontically Treated Teeth via NaOCl/MTAD Irrigation: A Preliminary Report

“…Ascorbic acid, a reducing agent that has been shown to be effective in reversing the oxidative potential of NaOCl (27,28), was also effective in preventing the photodegradation of doxycycline and minocycline (33,34). Clinically, although the formation of a yellow precipitate may be reduced by rinsing the NaOCl-treated dentin with water before the application of MTAD, the oxidative potential remains within dentin after rinsing of the NaOCl (27).…”

“…It is known from the literature that photochemical oxidation of tetracycline derivatives may be prevented by the use of reducing agents (30,32,33), most notably with reduced glutathione (32). Ascorbic acid, a reducing agent that has been shown to be effective in reversing the oxidative potential of NaOCl (27,28), was also effective in preventing the photodegradation of doxycycline and minocycline (33,34).…”

Spectral distribution of the luminescence generated during oxidation of doxycycline

“…Moreover, the emission in the blue-green region is also sensitive to the presence of 'O 2 quenchers. The data above lead us to the conclusion that an emission from 'O 2 -dimols 9 2 O 2 ['A g , 1 …”

“…All experiments were performed at a temperature of 310 K with the exception of the fluorescence experiments carried out at 292 K. The spectral distribution of the chemiluminescence (CL) was estimated in a circulation system using a set of calibrated cut-off filters (GOST9411-66) and an EMI9203B photomultiplier connected with an amplifier (Product for Research -USA). The method has been described previously 1 . The spectra were recorded ten times within the recording time of 10 s in the wavelength range 400-750 nm with a spectral resolution of 10 nm in this region.…”

Characterization of the superoxide anion radical scavenging activity by tetracycline antibiotics in aprotic media

“…During the past two decades concern has grown about the adverse effects of antibiotics and other pharmaceuticals on human and ecological heath. Tetracyclines have been reported to be initiators of genetic variants of microorganisms, due to the production of oxygen reactive species (ROS), such as superoxide anion radical () and its subsequent products, hydroxyl radical (), hydrogen peroxide (H 2 O 2 ) and singlet oxygen (), when involved in photochemical oxidation in aqueous solution , autoxidation or oxidation with a Fenton reagent . It has been established that these compounds also can initiate damage to cell membranes and ribosomes ; however, the precise mechanisms by which the drugs exert their toxic actions remain unclear.…”