Dentuto Pasquale L, Catucci Lucia, Cosma Pinalysa, Fini Paola, Agostiano Angela, D'Accolti Lucia, Trevithick-Sutton Colleen C, Foote Christopher S
Dipartimento di Chimica, Università di Bari, Via Orabona 4, 70126 Bari, Italy.
J Phys Chem B. 2005 Jan 27;109(3):1313-7. doi: 10.1021/jp047132p.
The interactions between chlorophyll a and two beta-cyclodextrins, that have the same cavity size but different substituents, were studied in aqueous solutions. These supramolecular host-guest complexes were examined by a combination of UV/vis absorption, circular dichroism, NMR, and steady-state and time-resolved fluorescence measurements. The results indicate that all cyclodextrins solubilize the pigment mainly in monomeric form in water. The pigment forms 1:1 complexes with the heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin and 1:2 complexes with the hydroxypropyl-beta-cyclodextrin. In such complexes the methyl groups of the cyclodextrin inner cavity are involved in the interaction with the pigment as evidenced by NMR measurements. We also measured the luminescence of singlet oxygen photosensitized by chlorophyll a in the inclusion complexes.
研究了叶绿素a与两种具有相同空腔尺寸但取代基不同的β-环糊精在水溶液中的相互作用。通过紫外/可见吸收、圆二色性、核磁共振以及稳态和时间分辨荧光测量等方法对这些超分子主客体复合物进行了研究。结果表明，所有环糊精在水中主要以单体形式溶解色素。色素与七（2,3,6-三-O-甲基）-β-环糊精形成1:1复合物，与羟丙基-β-环糊精形成1:2复合物。核磁共振测量表明，在这类复合物中，环糊精内腔的甲基参与了与色素的相互作用。我们还测量了包合物中叶绿素a光敏化产生的单线态氧的发光。
