Related Experiment Video
Updated: Aug 10, 2026

An In Vitro Approach to Photodynamic Therapy
Published on: August 17, 2018
Photodynamic effects of two hydroxyanthraquinones
M Rajendran1, S Ramasamy, C Rajamanickam
1Department of Chemistry, NMSSVN College, Madurai 625 019, Tamil Nadu, India.
Abstract:
The aim of this work was to investigate the photodynamic action of electron-rich anthraquinones, viz., cynodontin (CYN) and cynodontin-5,8-dimethylether (CYNM). Both optical and EPR methods are used to detect the generation of singlet oxygen. Based on RNO bleaching, relative to rose bengal (RB), singlet oxygen generating efficiencies of CYN and CYNM are derived to be 0.055 and 0.254, respectively. The formation of superoxide anion via electron transfer to O2 was monitored by optical spectroscopy, using SOD-inhibitable cytochrome c reduction assay. The production of O2-* is enhanced in the presence of electron donors such as EDTA and NADH. Photolysis of CYN and CYNM in DMSO, in the presence of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), generates a multi-line EPR spectrum, characteristic of spin adduct mixture of O2-* and *OH. Both optical and ESR measurements indicate that O2-* (Type I) and 1O2 (Type II) paths are involved in CYN and CYNM photodynamic action.
More Related Videos
07:12Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
10:05Stimulation of Stem Cell Niches and Tissue Regeneration in Mouse Skin by Switchable Protoporphyrin IX-Dependent Photogeneration of Reactive Oxygen Species In Situ
Published on: May 8, 2020
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Variables Affecting Phosphorescence and Fluorescence