Transmembrane Electron Transfer Catalyzed by Porphyrin Derivtives

1)合成了以亚甲基(CN)为间隔基团的聚乙二醇联联卟啉衍生物(方案1)、聚乙二醇亚甲基(CN)-MPFPP(M=H_2，Mn；n=0，5，11)、PEG-C_(11)-MTTP(M=H_2，Mn)和PEG-C_0-MPFPPBr_8(M=H_2，Mn)(方案1)。聚乙二醇[PEG]连接的氟化卟啉衍生物的卟啉部分已固定在脂质双层上。聚乙二醇化的氟化卟啉容易与磷脂双层结合，对H_2O_2等氧化剂具有化学稳定性。在磷脂连接的锌卟啉PE-C_0-ZnPFPP(方案1)与外加的聚乙二醇-CN-H_2PFPP(n=0，5，11)之间发生了有效的能量转移，这取决于CN的长度和卟啉的结构。-MnTTP表明，卟啉对电子转移有显著的加速作用，尤其是当n=11时。聚乙二醇-C-…和聚乙二醇-C_TPP-的比较讨论了更多&lt；11&gt；-MnTTP催化的电子转移。2)合成了含二亚甲基的锌杂化卟啉二聚体(ZnTTP-C2-H_2PFPP、ZnTTP-C2-H_2TTP、ZnPFPP-C_2-H_2PFPP和ZnPFPP-C_2-H_2TTP)和卤化锰卟啉二聚体(MnPFPP-C2-MnPFPP、MnPFPP-C2-MnDCPP和MnDCPP-C2-MnDCPP)，并用紫外可见光谱、荧光光谱和循环伏安图进行了表征。这些卟啉二聚体可以被包埋在脂膜的脂双层中。卤化卟啉二聚体的氧化还原电势随着卟啉环上卤素含量的增加而增加。在共价连接的锌杂化二聚体中，观察到有效的单重态能量从锌的卟啉转移到自由碱的卟啉，这取决于卟啉的结构。卤化卟啉锰二聚体具有跨膜电子转移和甲苯被H_2O_2羟基化的催化活性，这些催化活性取决于卤代部分在卟啉环上的空间位阻效应和咪唑的存在。3)在(1)，MnTTP-(CH2)n-MNP(Coome)3，n=2，3，12催化下，膜中的电子转移增强，尤其是当n=2或3on(1)时，咪唑的存在。此外，还观察到在玻碳电极上浇铸的膜中的卟啉之间的电子转移增强，特别是在含有锰原卟啉二甲酯的亲水角蛋白膜(MnPPDME)中。咪唑类化合物在含MnPPDME的疏水S-氰乙基化角蛋白膜的电子传递过程中起着重要作用。较少

1) Poly (ethylene glycol) [PEG] -linked porphyrin derivatives separated by spacer methylene groups (Cn), PEG-Cn-MPFPP (M = H_2, Mn ; n = 0,5,11), PEG-C_<11>-MTTP (M = H_2, Mn), and PEG-C_0-MPFPPBr_8 (M = H_2, Mn) (Scheme 1) were synthesized. The porphyrin portion of poly (ethylene glycol) [PEG] -linked fluorinated porphyrin derivative has been anchored onto a lipid bilayr. PEG-linked fluorinated porphyrins associated easily with phospholipid bilayrs and are chemically stable against oxidant such as H_2O_2. An efficient energy transfer from phospholipid-linked zinc porphyrin, PE-C_0-ZnPFPP (Scheme 1) to externally added PEG-Cn-H_2PFPP (n = 0,5,11) in the lipid bilayr was observed, depending on the length of Cn and the porphyrin structure.Ground state transmembrance electron transfer catalyzed by PEG-Cn-MnPFPP (n = 0,5,11) and PEG-C_<11>-MnTTP revealed that the porphyrin causes a significant accelerated electron transfer especially when n = 11. Comparison of PEG-C_<11>-MnPFPP- and PEG-C_ … More <11>-MnTTP-catalyzed electron transfer is discussed. The electron transfer rate was controlled not only by the separated spacer methylene groups between the porphyrin and PEG moieties but also by the structures of porphyrins.2) Zinc hybrid porpyrin dimer (ZnTTP-C2-H2PFPP,ZnTTP-C2-H2TTP,ZnPFPP-C2-H2PFPP and ZnPFPP-C2-H2TTP) and manganese halogenated porphyrin dimers (MnPFPP-C2-MnPFPP,MnPFPP-C2-MnDCPP,and MnDCPP-C2-MnDCPP) covalently bridged by a dimethylene moiety (Scheme 1) were synthesized and characterized by UV-vis spectra, fluoresecence spectra and cyclic voltammograms. These porphyrin dimers could be embedded into the lipid bilayrs of liposomal membrance. The redox potential of halogenated porphyrin dimers increased with increasing of halogen portions on the porphyrin rings. An efficient energy transfer of the excited singlet state in the covalently-linked zinc hybrid dimers from zinc porphyrin to a free base porphyrin was observed, depending on the porphyrin structure. The manganese halogenated porphyrin dimers showed catalytic activities of transmembrance electron transfer and the hydroxylation of toluene by H2O2, in which these catalytic activities depend on the steric effect of halogen portions on the porphyrin ring and also the presence of imidazole.3) Transmembrane electron transfer across S-cyanoethylated keration (SCEK) and liposomal membranes catalyzed by (1), MnTTP- (CH2) n-MnP (COOMe) 3, n=2,3,12 showed that an enhanced electron transfer wasobserved especially when n=2or3 on (1) in these membranes and imidazole was present. Furthermore, enhanced electron transfer between porphyrins in membranes cast on a glassy carbon electrode was observed especially in hydrophilic keratin membranes containing manganese protoporphyrin dimethyl esters (MnPPDME). An imidazole derivative playd an important role on the electron transfer in hydrophobic S-cyanoethylated keratin membranes containing MnPPDME. Less