Synthesis of a novel hypocrellin B derivative and its photogeneration of semiquinone anion radical.

Abstract

In order to improve the photosensitizing activity of HB further, the complex of 5,8-di-Br-HB with Al(3+) was first designed and synthesized in high yield. 5,8-di-Br-HB forms a 2:1 type (metal-ligand ratio) complex with Al(3+) measured by molar ratio and continuous variation methods. The new photosensitizer was characterized by UV-Vis, IR, 1H NMR and elemental analysis measurements. Based on the above experimental results, we first proposed a polymer-like structural model of the complex. The water-solubility and red absorption of the [Al(2)(5,8-di-Br-HB)Cl(4)](n) complex are both enhanced over hypocrellin B. In addition, the EPR and spectrophotometric measurements demonstrate that semiquinone anion radical of [Al(2)(5,8-di-Br-HB)Cl(4)](n) can be produced by [Al(2)(5,8-di-Br-HB)Cl(4)](n) photosensitization. The generation efficiency of ([Al(2)(5,8-di-Br-HB)Cl(4)](n))(.-) is almost equal to that of HB(.-). These results obtained indicated that [Al(2)(5,8-di-Br-HB)Cl(4)](n)was at least a favorable Type I phototherapeutic agent.

• Authors: J H Ma, J Q Zhao, L J Jiang
• Journal: Journal of photochemistry and photobiology. B, Biology (J Photochem Photobiol B) Vol. 61 Issue 3 Pg. 122-8 (Aug 30 2001) ISSN: 1011-1344 [Print] Switzerland
• PMID: 11535411 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Al2(5,8-di-Br-HB)Cl4
• Aluminum Compounds
• Benzoquinones
• Organometallic Compounds
• Photosensitizing Agents
• Quinones
• semiquinone radicals
• Perylene
• Aluminum
• hypocrellin B

Topics

• Aluminum
• Aluminum Compounds (chemical synthesis, chemistry)
• Benzoquinones (chemical synthesis, chemistry)
• Molecular Structure
• Organometallic Compounds (chemical synthesis, chemistry)
• Perylene (analogs & derivatives)
• Photosensitizing Agents (chemical synthesis, chemistry)
• Quinones (chemical synthesis, chemistry)
• Spectrophotometry, Ultraviolet (methods)