Photosensitization mechanism of active species by the complex of hypocrellin B with aluminum ion.

Abstract

To improve the water solubility and red absorption of the parent hypocrellin B (HB), the complex of HB with aluminum ion has been first synthesized in high yield. The photodynamic action of Al(3+)-HB, especially the generation mechanism of active species, ([Al(3+)-HB].-, O2.- and 1O2) was studied using electron paramagnetic resonance (EPR) and spectrophotometric methods. In the deoxygenated DMSO solution of Al(3+)-HB, the semiquinone anion radical of Al(3+)-HB is photogenerated via the self-electron transfer between the excited and ground state species. The presence of electron donor significantly promotes the reduction of Al(3+)-HB. When oxygen is present, superoxide anion radical (O2.-) is formed via the electron transfer from [Al(3+)-HB].- to the ground state molecular oxygen. Singlet oxygen (1O2) can be produced via the energy transfer from triplet Al(3+)-HB to ground state oxygen molecules. Furthermore, it is very significant that the accumulation of [Al(3+)-HB].- would replace that of O2.- or 1O2 with the consumption of oxygen in the sealed system.

• Authors: J H Ma, J Q Zhao, L J Jiang
• Journal: Free radical research (Free Radic Res) Vol. 35 Issue 5 Pg. 607-17 (Nov 2001) ISSN: 1071-5762 [Print] England
• PMID: 11767418 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cations
• Cytochrome c Group
• Free Radicals
• Photosensitizing Agents
• Quinones
• Reactive Oxygen Species
• Singlet Oxygen
• Perylene
• Aluminum
• Superoxide Dismutase
• hypocrellin B

Topics

• Aluminum (chemistry, pharmacology)
• Animals
• Cations
• Cytochrome c Group (chemistry)
• Electron Spin Resonance Spectroscopy
• Free Radicals (chemistry)
• In Vitro Techniques
• Molecular Structure
• Oxidation-Reduction
• Perylene (analogs & derivatives, chemistry, pharmacology)
• Photochemistry
• Photosensitizing Agents (chemistry, pharmacology)
• Quinones (chemistry, pharmacology)
• Reactive Oxygen Species (chemistry)
• Singlet Oxygen (chemistry)
• Spectrophotometry
• Spin Trapping
• Superoxide Dismutase (antagonists & inhibitors)