Supramolecular Chemistry Composed of Porphyrins and Cyclodextrins

1)卟啉全甲基化环糊精络合物：我们发现一些水溶性的四芳基卟啉与全O-甲基化β-环糊精(TME-β-CD)形成非常稳定的1：2包合物。结果表明，该体系可用于制备各种超分子体系。2)卟啉-TMe-β-Cd络合物的形成机理：研究了极稳定的卟啉-TMe-β-Cd络合物的形成机理。结果，阐明了TME-β-CD可以根据客体的形状改变其形状，从而产生生物体系中的“诱导-配位型络合”。主客体之间的最佳范德华接触是通过诱导配合型包裹体实现的。3)杂卟啉阵列的形成：利用…建立了一种非常方便的制备杂卟啉阵列的方法进一步将研究结果应用于水溶性卟啉与TME-β-CD的络合作用。支架是四苯基卟啉，其外围苯基的对位通过全O-甲基化的β-环糊精部分连接。这种卟啉-环糊精偶联物只需与另一种卟啉溶液混合即可形成杂卟啉阵列。只需将偶联物的溶液与水溶性阴离子卟啉(β)的溶液混合，就可以非常有效地将能量从锌的络合物转移到络合物的游离碱上。4)Met-Myogbbin模型：阴离子卟啉的Fe(III)络合物(Fe(III)TPP)与TME-TPP-Cd形成1：2的包合物。这种络合物可以作为MET-肌红蛋白模型，其Fe(III)中心与水介质中的各种阴离子结合。在没有TME-β-CD和TME-β-CD的情况下，水溶液中没有阴离子与Fe(III)TPP结合，这一事实似乎表明TME-TPP-CD在生物体系中的功能类似于蛋白质。Fe(III)-TPPS/FME-β-Cd络合物与阴离子结合具有较高的选择性，即N3-选择性地与络合物结合。亲水性、碱性和阴离子的形状是决定阴离子结合的Fe(III)TPP/TME-β-CD络合物稳定性的因素。5)肌红蛋白模型和可逆的O2结合：由Fe(III)TPP和全O-甲基化的β-环糊精二聚体构建了MET-肌红蛋白模型，其中两个环糊精部分与以吡啶为近端碱基的桥相连。我们将这种模式称为“MET-HYOCD”。二亚硫酸盐还原MET-HbCD生成HbCD(Fe(II)TPPS/环糊精二聚体)，可与氧可逆结合。氧合血球蛋白在pH 6.0的磷酸盐缓冲液中的半衰期为30h。测得氧的亲和力为17Torr。HemoCD显示出与肌红蛋白类似的功能。本系统是第一个在水溶液中工作的肌红蛋白或血红蛋白模型的例子。较少

1) Porphyrin Permethylated Cyclodextrin Complexes : We found that some water-soluble tetraarylporphyrins form extremely stable 1:2 inclusion complexes with per-O-methylated β-cyclodextrin (TMe-β-CD). The complexes were formed quantitatively in aqueous solutions even when the concentrations of both host and guest were 10-6 M. The results strongly suggest the possibility of this system to be utilized for preparing various supramolecular systems2) Mechanism for Formation of Porphyrin-TMe-β-CD Complexes : Mechanism for formation of extremely stable porphyrin-TMe-β-CD complexes was studied. As a result, it was clarified that TMe-β-CD can alter its shape according to the shape of a guest resulting in "induced-fit type complexation" as is found in biological systems. The optimum van der Waals contacts between the host and the guest are achieved by the induced-fit type inclusion.3) Formation of Heteroporphyrin Arrays : A very convenient method to prepare heteroporphyrin arrays was developed by … More applying the results on complexation of water-soluble porphyrins and TMe-β-CD. A scaffold is the tetraphenylporphyrin whose para-positions of the peripheral phenyl groups are attached by per-O-methylated β-cyclodextrin moieties. Such a porphyrin-cyclodextrin conjugate can form heteroporphyrin array just by mixing with another porphyrin solution. Very efficient energy transfer from zinc complex of water-soluble anionic porphyrin (ZnTPPS) to the free base porphyrin of the conjugate was achieved just by mixing the solution of the conjugate with that of ZnTPPS.4) Met-Myogbbin Model : Fe(III) complex of the anionic porphyrin (Fe(III)TPPS) forms a very stable 1:2 inclusion complex with TMe-β-CD. Such a complex can act as a met-myoglobin model whose Fe(III) center is bound to various anions in aqueous media. The fact that no anion binding to Fe(III)TPPS occurs in aqueous solution in the absence of TMe-β-CD, TMe-β-CD seems to show the function similar to proteins in biological system. High selectivity was found in anion binding to Fe(III)TPPS/FMe-β-CD complex; namely N3- is selectively bound to the complex. Hydrophilicity, basicity, and shape of an anion are the factors to determine the stability of the anion-bound Fe(III)TPPS/TMe-β-CD complex.5) Myogbbin Model and Reversible O2 Binding : A met-myoglobin model was constructed by Fe(III)TPPS and a per-O-methylated β-cyclodextrin dimer where two cyclodextrin moieties were linked with a bridge containing a pyridine moiety as a proximal base. We call such a model "met-hemoCD". Met-hemoCD was reduced by dithionite to form hemoCD (Fe(II)TPPS/cyclodextrin dimer), which bound dioxygen reversibly. The half life time of oxy-hemoCD was 30h in pH 6.0 phosphate buffer. The dioxygen affinity was determined to be 17 Torr. HemoCD shows the functions similar to myoglobin. The present system is the first example of the model of myoglobin or hemoglobin that works in aqueous solution. Less