Photodynamic Properties of Hypocrellin A, Complexes with Rare Earth Trivalent Ions: Role of the Excited State Energies of the Metal Ions
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- 作者：Zhanghua Zeng ; Jiahong Zhou ; Yan Zhang ; Rui Qiao ; Shengqin Xia ; Jinrong Chen ; Xuesong Wang ; Baowen Zhang
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：March 15, 2007
- 年：2007
- 卷：111
- 期：10
- 页码：2688 - 2696
- 全文大小：236K
- 年卷期：v.111,no.10(March 15, 2007)
- ISSN：1520-5207
文摘
Fifteen complexes of hypocrellin A (HA) with rare earth trivalent ions (except Pm3+) along with the complexof HA with Sc3+ were prepared, and their photodynamic activities, including absorption in the phototherapeuticwindow (600-900 nm); water-solubility; triplet lifetime; generation of reactive oxygen species (ROS), suchas singlet oxygen (1O2), superoxide anion radical (O2-
), and hydroxyl radical (OH); generation of semiquinoneanion radical; and affinity to DNA, as well as photosensitized damage on calf thymus DNA (CT DNA), werecompared in detail using the UV-visible spectrum, fluorescence spectrum, spin-trapping EPR technique,and laser photolysis technique. All complexes exhibit a red-shifted absorption spectrum, an increased absorbanceabove 600 nm, improved water solubility, and an enhanced affinity to CT DNA over the parent HA. For ionsthat possess low-energy excited states, including Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Tb3+, Dy3+, Ho3+, Er3+,Tm3+, and Yb3+, the corresponding complexes show undetectable or nearly undetectable fluorescence, a tripletexcited-state lifetime, generation of ROS, and photodamage in CT DNA. In contrast, for ions that do notpossess low-energy excited states, including Sc3+, Y3+, La3+, Gd3+, and Lu3+, the corresponding complexesexhibit higher photodamage abilities with CT DNA with respect to HA, benefitting from both their comparableor even higher 1O2 quantum yields and an electrostatic affinity that is higher for DNA than HA.
), and hydroxyl radical (OH); generation of semiquinoneanion radical; and affinity to DNA, as well as photosensitized damage on calf thymus DNA (CT DNA), werecompared in detail using the UV-visible spectrum, fluorescence spectrum, spin-trapping EPR technique,and laser photolysis technique. All complexes exhibit a red-shifted absorption spectrum, an increased absorbanceabove 600 nm, improved water solubility, and an enhanced affinity to CT DNA over the parent HA. For ionsthat possess low-energy excited states, including Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Tb3+, Dy3+, Ho3+, Er3+,Tm3+, and Yb3+, the corresponding complexes show undetectable or nearly undetectable fluorescence, a tripletexcited-state lifetime, generation of ROS, and photodamage in CT DNA. In contrast, for ions that do notpossess low-energy excited states, including Sc3+, Y3+, La3+, Gd3+, and Lu3+, the corresponding complexesexhibit higher photodamage abilities with CT DNA with respect to HA, benefitting from both their comparableor even higher 1O2 quantum yields and an electrostatic affinity that is higher for DNA than HA.