TY  - JOUR
A1  - Rancan, Fiorenza
A1  - Wiehe, Arno
A1  - Nöbel, Maria
A1  - Senge, Mathias O
A1  - Al Omari, Saleh
A1  - Böhm, Fritz
A1  - John, Matthias
A1  - Röder, Beate
T1  - Influence of substitutions on asymmetric dihydroxychlorins with regard to intracellular uptake, subcellular localization and photosensitization of Jurkat cells
N2  - The search for new efficient sensitizers for photodynamic therapy (PDT) points to improve photophysical properties like absorption in the red region and singlet oxygen quantum yield as well as to control the localization of the sensitizer within the tumour cell. Depending on their physicochemical properties and their uptake mechanism, sensitizers can reach different intracellular concentrations and localize in different subcellular compartments. Moreover, the preferential localization of a sensitizer in target organelles, like mitochondria or lysosomes, could determine the cell death mechanism after PDT. This study aimed to investigate the influence of substitutions on dihydroxychlorins with regard to intracellular uptake, subcellular localization and cell death pathway. Moreover, the effect of a liposome-based delivery system was tested. The intracellular uptake was found to be strictly dependent on the sensitizer molecular structure and the means of its delivery. The most polar sensitizer in this study (compound 3) had, depending on incubation time, an intracellular concentration 2-8 times higher than the unsubstituted chlorin 1. All investigated photosensitizers localize predominantly in lysosomes but after longer incubation times weak fluorescence intensity was also detected in mitochondria and Golgi apparatus. The cell death pathway was found to be influenced by the sensitizer intracellular concentration and the applied light doses. In general, the increasing amphiphilicity of the sensitizer molecules is correlated with an increased sensitizer uptake and an increased rate of necrotic cells after irradiation. (C) 2004 Elsevier B.V. All rights reserved
Y1  - 2005
SN  - 1011-1344
ER  - 
TY  - JOUR
A1  - Wiehe, A.
A1  - Shaker, Y. M.
A1  - Brandt, J. C.
A1  - Mebs, S.
A1  - Senge, Mathias O.
T1  - Lead structures for applications in photodynamic therapy : Part 1: Synthesis and variation of m-THPC (Temoporfin) related amphiphilic A(2)BC-type porphyrins
N2  - Photodynamic therapy (PDT) is a developing modality for the treatment of certain tumorous and other diseases. Considerable progress has been made in recent years in the search for new photosensitizers, in particular elucidating the role of localization of the photosensitizer. Known successful photosensitizers of the tetrapyrrole type are amphiphilic molecules, preferably localizing in cellular membrane structures. Thus, the quest for new photosensitizers requires the synthesis of unsymmetrically Substituted (amphiphilic) tetrapyrroles. In this article. we describe strategies for the de novo synthesis of amphiphilic tetrapyrroles using a 3-hydroxyphenyl substituted tetrapyrrolic system (Temoporfin) as the lead structure. From an applied science-oriented approach, such a set of amphiphilic porphyrins is best synthesized by combining well-developed condensation methods with subsequent functionalization via organolithium compound or transition metal catalyzed coupling protocols. Starting from simple A(2)- or AB-porphyrins, the synthesis of A(2)B-, A(3)-, A(3)B-, and A(2)BC-porphyrins with a mixed hydrophilic/hydrophobic substitution pattern is described. Because of the versatility of this approach to unsymmetrically Substituted porphyrins it is also applicable to other areas where porphyryns with a tailor-made substitution patterns are needed. for example. catalysts or molecular electronic devices based on tetrapyrroles. (c) 2005 Elsevier Ltd. All rights reserved
Y1  - 2005
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Ryppa, C.
A1  - Senge, Mathias O.
T1  - Dodecasubstituted porphyrins : an easily accessible type of dendritic porphyrins with tunable properties
N2  - Dodecasubstituted dendritic porphyrins with nonplanar macrocycles were synthesized by a convergent approach via Lindsey condensation reactions in good yields
Y1  - 2004
SN  - 0385-5414
ER  - 
TY  - JOUR
A1  - Senge, Mathias O.
A1  - Hatscher, S. S.
A1  - Wiehe, A.
A1  - Dahms, Katja
A1  - Kelling, Alexandra
T1  - The dithianyl group as a synthon in porphyrin chemistry : condensation reactions and preparation of formylporphyrins under basic conditions
Y1  - 2004
SN  - 0002-7863
ER  - 
TY  - JOUR
A1  - Barkigia, Kathleen M.
A1  - Renner, Mark W.
A1  - Senge, Mathias O.
A1  - Fajer, Jack
T1  - Interplay of axial ligation, hydrogen bonding, self-assembly, and conformational landscapes in high-spin Ni(II) porphyrins
N2  - The molecular structures of four bis-ligated high-spin Ni(II) complexes of the sterically crowded, nonplanar 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetranitroporphytin (NiOETNP) are reported. The ligands are imidazole (Im), imidazole plus 2-methylimidazole (2-MeIm) in the crystal lattice, 1-methylimidazole (1-MeIm), and 2,1,3- benzoselenadiazole (BSeD). Extensive intermolecular hydrogen bonding is observed in the three imidazole-ligated structures consisting of NH...O and CH...O bonding from the imidazoles to neighboring nitro groups and of NH...N interactions to a nearby 2-MeIm. The different modes of hydrogen bonding, typical of those frequently observed in proteins, mediate the self-assembly of discrete porphyrin dimers as well as more extensive two- and three-dimensional arrays. Only the bis-BSeD complex remains monomeric. The presence or absence of the different types of hydrogen bonds controls the orientations of the axial ligands and also modulates the conformations of the porphyrin skeletons. This interplay of axial ligation, hydrogen bonding, and self-assembly further illustrates the multi conformational landscapes that porphyrins can access as a function of their microenvironment. Such nonplanar deformations have been shown to significantly affect the optical, redox, magnetic, radical, and excited state properties of porphyrin derivatives. That hydrogen bonding can influence ligand interactions with neighboring functional groups as well as macrocycle conformations with their concomitant consequences on physical and chemical properties may thus be particularly relevant to the bioenergetic roles of porphyrin in vivo. These results also raise the question whether point mutations near porphyrins in vivo are structurally, and consequently functionally, innocent
Y1  - 2004
SN  - 1520-6106
ER  - 
TY  - JOUR
A1  - Senge, Mathias O.
A1  - Bischoff, Ines
T1  - SNAr reactions of beta-substituted porphyrins and the synthesis of meso substituted tetrabenzoporphyrins
N2  - Reaction of 2,3.7,8,12,13,17,18-octaethylporphyrin with LiR reagents containing functional groups readily yields meso substituted derivatives suitable for further transformations with residues such as -p-C6H5Br, -p-C6H5-C=CH - p-C6H5-NH2 or -(CH2)(3)-CH=CH2. Similar reactions of tetrabenzoporphyrin with alkyllithium reagents afforded the first entry into meso mono- and dialkylsubstituted tetrabenzoporphyrins while reaction of bicyclo[2.2.2]oct-type masked isoindole precursors with LiR followed by in situ retro-Diels-Alder reaction also afforded the 5-phenyl and 5,10- diphenyltetrabenzoporphyrins in high purity. (C) 2004 Elsevier Ltd. All rights reserved
Y1  - 2004
SN  - 0040-4039
ER  - 
TY  - JOUR
A1  - Senge, Mathias O.
A1  - Richter, J.
T1  - Synthetic, transformations of porphyrins : Advances 2002-2004
N2  - Contemporary methods for the modification of porphyrins are presented. In association with the Third International Conference on Porphyrins and Phthalocyanines (ICPP-3) a survey of current method developments and reactivity studies is made. The review focuses on synthetic transformations of porphyrins currently in use for various applications and on functional group transformations. A brief survey of important developments covers selectively the literature from late 2001 to early 2004. Copyright (c) 2004 Society of Porphyrins C Phthalocyanines
Y1  - 2004
SN  - 1088-4246
ER  - 
TY  - JOUR
A1  - Venkatraman, S.
A1  - Kumar, R.
A1  - Sankar, J.
A1  - Chandrashekar, T. K.
A1  - Sendhil, K.
A1  - Vijayan, C.
A1  - Kelling, Alexandra
A1  - Senge, Mathias O.
T1  - Oxasmaragdyrin-ferrocene and oxacorrole-ferrocene conjugates : Synthesis, structure, and nonlinear optical properties
N2  - Ferrocenyl macrocyclic conjugates involving 22pi oxasmaragdyrins and 18pi oxacorroles have been synthesized and characterized. The direct covalent linkage of the ferrocenyl moiety to the meso position of the macrocycle is achieved by simple oxidative coupling of appropriate precursors with trifluoroacetic acid as catalyst. The electronic coupling between the ferrocenyl moiety and the macrocyclic pi system is apparent from: a) the red shifts (293-718 cm(-1)) of the Soret and Q-bands in the electronic absorption spectra of ferrocenyl conjugates; b) the shift of oxidation potentials (50 130 mV) of both the ferrocene and the corrole rings to the positive potentials; and c) considerable shortening of the C-C bond which connects the ferrocene and the meso-carbon atom of the macrocycle. The single-crystal X-ray structure of oxasmaragdyrin-ferrocene conjugate 9 reveals the planarity of the 22pi skeleton with very small deviations of the meso-carbon atoms. The meso-ferrocenyl substituent has a small dihedral angle of 38degrees, making way for mixing of the molecular orbitals of the ferrocene and the macrocycle. However, the other two meso substituents are almost perpendicular to the mean plane, defined by the three meso carbon atoms. Classical C-(HO)-O-... and nonclassical C- H(...)pi interactions lead to a two-dimensional supramolecular network. Ferrocene-smaragdyrin conjugate 9 bonds to a chloride ion in the protonated form and a rhodium(i) ion in the free base form. Nonlinear optical measurements reveal a larger nonlinear refractive index (-5.83 x 10(-8) cm(2) W-1) and figure of merit (2.28 x 10(-8) cm(3)W(-1)) for the rhodium smaragdyrin-ferrocene conjugate 19 than for the others, suggesting its possible application in optical devices
Y1  - 2004
SN  - 0947-6539
ER  - 
TY  - JOUR
A1  - Senge, Mathias O.
A1  - Rossler, B.
A1  - von Gersdorff, J.
A1  - Schafer, A.
A1  - Kurreck, H.
T1  - The meso-beta-linkage as structural motif in porphyrin-based donor-acceptor compounds
N2  - Synthetic strategies for using the beta-linkage as a structural motif in electron transfer mimics have been tested. Exploratory syntheses of directly meso-beta-linked bis- and trisporphyrins and the first representative X-ray structure of a meso-beta-linked bisporphyrins are reported. The structure reveals a unique form of intramolecular- pi-pi stabilization between one porphyrin and a meso-aryl substituent in a second porphyrin unit that accounts for the stability of different atropisomers in trimers. Using beta-formyl porphyrins, dipyrromethanes, and suitable quinone precursor aldehydes, mixed condensations gave convenient access to porphyrin-porphyrin-quinone (P-P-Q) donor acceptor systems consisting of a meso-beta-linked bisporphyrin. a spacer, and a quinone acceptor. (C) 2004 Elsevier Ltd. All rights reserved
Y1  - 2004
SN  - 0040-4039
ER  - 
TY  - JOUR
A1  - Rath, Harapriya
A1  - Anand, V. G.
A1  - Sankar, J.
A1  - Venkatraman, S.
A1  - Chandrashekar, T. K.
A1  - Joshi, Bhawani S.
A1  - Khetrapal, C. L.
A1  - Schilde, Uwe
A1  - Senge, Mathias O.
T1  - Core-Modified Hexaphyrins; Characterization of Two- and Four-Ring Inverted 26 ô Aromatic Macrocycles
Y1  - 2003
UR  - http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/ol035408q
ER  -