Polysaccharide films containing chitosan, methylcellulose, and a mixture of these polysaccharides in various ratios were prepared and modified with meso-tetrakis(4-sulfonatophenyl)porphyrin in an aqueous medium at pH 7. The modified films were compared with the initial films using spectroscopic methods and microscopic imaging. Electronic (UV-vis absorption, electronic circular dichroism (ECD)) and vibrational (FTIR and Raman) spectra showed that the porphyrin macrocycles had a strong affinity toward chitosan and did not interact with the methylcellulose. The total porphyrin uptake depended on the chitosan: methylcellulose ratio and pure methylcellulose films did not retain porphyrin macrocycles. ECD measurements detected the presence of optically active porphyrin species bound to the films. SEM and AFM images confirmed that the porphyrin macrocycles caused structural changes on the film surface and within the film layer.
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http://dx.doi.org/10.1021/bm2015366 | DOI Listing |
Chem Asian J
December 2024
IIT Roorkee: Indian Institute of Technology Roorkee, Department of Chemistry, Room No D-307, Department of Chemistry, Indian Institute of Technology Roorkee, 247667, Roorkee, INDIA.
The extent of conformational alteration of the porphyrin macrocycle during the course of protonation was observed, both experimentally and theoretically. For synthesized β-substituted octaphenylporphyrin (OPP) ring systems this macrocyclic distortions have been investigated by spectroscopic and computational analysis. Protonation induced nonplanarity in macrocyclic system is experimentally observed in a single step during spectrophotometric titration.
View Article and Find Full Text PDFIUCrdata
October 2024
Department of Chemistry, Kuwait University, PO Box 5969, Safat 13060, Kuwait.
The crystal structure of a glycosyl-ated porphyrin () system, CHNO, where two iso-propyl-idene protected galactose moieties are attached to the position of a substituted tetra-aryl porphyrin is reported. This structure reveals that the parent porphyrin is planar, with the galactose moieties positioned above and below the porphyrin macrocycle. This orientation likely prevents porphyrin-porphyrin H-type aggregation, potentially enhancing its efficiency as a photosensitizer in photodynamic therapy.
View Article and Find Full Text PDFBiomater Sci
December 2024
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Bld. 1 Vavilov Street, 119334 Moscow, Russian Federation.
The tetrapyrrolic macrocycle as a scaffold for various chemical modifications provides broad opportunities for the preparation of complex multifunctional conjugates suitable for binary antitumor therapies. Typically, illumination with monochromatic light triggers the photochemical generation of reactive oxygen species (ROS) (photodynamic effect). However, more therapeutically valuable effects can be achieved upon photoactivation of tetrapyrrole derivatives.
View Article and Find Full Text PDFInorg Chem
December 2024
Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
Trivalent actinide expanded porphyrin complexes have been of synthetic interest since the isolation of the series of trivalent lanthanide texaphyrin complexes in 1992, however, synthesis of these actinide-based complexes has not yet been achieved. In this work, a computational study with relativistic density functional theory was performed to determine how trivalent actinide ions (Ac through Lr) interact with Schiff base expanded porphyrin macrocycles in a methanol solvent as an alternate pathway to stabilization. A thorough analysis of structural parameters, electronic structure, stability of microsolvation environments, and relative binding energies provided insight into the most stable structures.
View Article and Find Full Text PDFChemistry
December 2024
Hiroshima University, Chemistry, 1-3-1 Kagamiyama, 739-8526, Higashi-Hiroshima, JAPAN.
The intermolecular host-guest complexation of head-to-tail monomers consisting of cleft-shaped bisporphyrin and trinitrofluorenone units connected by a chiral binaphthyl linker was employed to construct helically twisted supramolecular polymers. Results from 1H NMR, diffusion-ordered NMR spectroscopy, and viscometry experiments revealed that the supramolecular polymerization of these monomers follows a ring-chain competition mechanism. The introduction of bulky substituents at the linker significantly suppressed the formation of macrocyclic oligomers, whereas smaller alkyl chains facilitated the formation of the cyclic form.
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