Free-base C60-(meso-tri-thienyl)porphyrin dyads and their Zn-complexes: new additions to the library of donor-acceptor assemblies

The article introduces covalently functionalized free-base porphyrin fullerene (C60) dyads and their corresponding zinc complexes. The donor unit is a meso-tri substituted thienyl porphyrin. The mode of attachment of the porphyrin to the fullerene unit differs in the lengths of the spacers linking the donor and acceptor units. The characterization of the four dyads through 1HNMR, MALDI-TOF, UV-Vis, and emission spectra confirm the formation of the dyads. Additionally, the study of fluorescence lifetime reveals the impact of the length of the flexible linkers on the free-base and zinc complexes of the dyads. Each dyad showed the presence of two types of fluorescent transients corresponding to fluorescence quenching through either charge transfer or intermolecular π-π interactions. The recorded fluorescent lifetime values for the dyads are: T3OHA1C60 (1 = 1.275 and 3 = 4.725 ns), T3OHA1C60Z (1 = 0.758 and 3 = 2.660 ns), T3OHA2C60 (1 = 0.819 and 2 = 2.456 ns), and T3OHA2C60Z (1 = 0.993 and 2 = 3.675 ns), the fluorescent quantum yields are 0.038, 0.041, 0.031, and 0.019, respectively

Porphyrins in Photodynamic Therapy: A Review

Porphyrins have emerged as versatile and highly effective photosensitizers in the field of photodynamic therapy (PDT). This promising therapeutic approach relies on the light-induced generation of reactive oxygen species (ROS) by photosensitizing agents. This comprehensive review explores the multifaceted role of porphyrins across various PDT applications, encompassing anticancer PDT, immuno-PDT, antimicrobial PDT, and antiviral PDT. Porphyrins exhibit the potential to serve as organic supramolecular platforms for developing various photosensitizers (PSs) tailored for specific PDT modalities. The exceptional capacity of porphyrins to specifically accumulate in target cancer cells or microorganisms, their proficiency in generating ROS upon exposure to light, and their capability to amass within cell mitochondria to facilitate apoptosis establish porphyrins as invaluable assets in a wide array of therapeutic applications. Ongoing research endeavours and clinical investigations continually unveil the vast potential of porphyrin-based PDT in combatting a wide range of diseases, spanning from cancer and infections to viral ailments. Furthermore, porphyrins hold promise in addressing drug-resistant cancers and antimicrobial resistance through non-invasive PDT, offering efficient alternatives to commercially available PDT drugs. In the context of advanced cancer management, porphyrin-based PDT offers the prospect of combinatorial therapy, enabling a sequence of immunogenic post-PDT actions that can effectively overcome anticancer resistance and tackle metastatic cancers. The future of PDT appears promising, with porphyrin scaffolds expected to play pivotal roles in advancing this field

Cancer photocytotoxicity and anti-inflammatory response of <i>cis</i>-A₂B₂ type <i>meso-p</i>-nitrophenyl and <i>p</i>-hydroxyphenyl porphyrin and its zinc(<scp>ii</scp>) complex: a synthetic alternative to the THPP synthon

In comparison with the popular synthetic synthon THPP, the cis-A2B2 type of porphyrin derivative and its zinc(ii) complex PN2(OH)2Zn offer more promising photochemical and photobiological outcomes.</p