A TD-DFT Study on the Photo-Physicochemical Properties of Chrysophanol from Rheum

International Journal of Molecular Sciences

Xue Zhao²  Zebao Zheng²  Shuai Feng²  Zhiqiang Shi¹ 

[1] Department of Materials Science and Chemical Engineering, Taishan University, Taian 271000, China;Department of Chemistry & Environment Science, Taishan University, Taian 271021, China

关键词: TD-DFT;    chrysophanol;    excited states;    photosensitization mechanisms;   

DOI  :  10.3390/ijms10073186

来源: mdpi

【 摘 要 】

As a naturally occurring anthraquinone pigment, chrysophanol (MHAQ) has attracted considerable attention in recent years owing to its efficient photosensitivity under the solar spectrum. Considering the successful use of time-dependent density functional theory (TD-DFT) in investigating the photo-physicochemical behaviors of dyes and pigments, we performed a study by means of TD-DFT calculations, which provided us with various excited state properties of chrysophanol, including absorption spectrum, lowest triplet excited-state energy, vertical electron affinity and vertical ionization potential. On the basis of the calculated results, the photosensitive mechanisms of chrysophanol were discussed and some deeper insights were gained. First, we indicated that the experimentally observed chrysophanol’s photo-damage to DNA in oxygen-free media is more likely to arise from MHAQ^•+ rather than from T₁ state chrysophanol. Second, we revealed that it is the MHAQ^•− that is responsible for the O₂^•− generation in solvents. Based on the photosensitive activities, chrysophanol may be potentially used as the photodynamic medicine for clinical therapy of the diseases occurring on the shallow surface and vascular capillary diseases.

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.