Covalent synthesis, structural characterization and biological behavioral study of tin captured porphyrin-polyoxometalate based polymeric hybrid

Abstract

The combination of polyoxometalates(POMs) and tin-based porphyrin in a variety of modes ofinteractionturned out to be the key for unlocking new directions in the study of biological activities. In this study, a new sandwich type covalently attached porphyrin C52H48N6O6Sn (SnTPP-Di-Tris) and Anderson POM-porphyrin polymeric hybrid, with molecular formula as [{N(C4H9)4}8{C62H60Mn2Mo12N6O48Sn·CH3CN}](PolySnP@POM). These compounds were clearly characterized and their formation was confirmed by spectroscopic (UV–visible, FT-IR, NMR) techniques, powder XRD, elemental analyses, cyclic voltammetry and scanning electron microscopy techniques(SEM). SnTPP-Di-Tris and PolySnP@POM were evaluated for drug delivery, DNA binding, protein binding and antibacterial studies. It is found that drug loading efficiency was 89% and 93% for PolySnP@POM and SnTPP-Di-Tris, respectively. While drug release was more efficient in acidic media (pH = 3) as 100 % for both compounds in 1.5 h as compared to basic media (pH = 11) 65.93% and 72.6% for SnTPP-Di-Tris and PolySnP@POM, respectively. Uv–visible study of SnTPP-Di-Tris and PolySnP@POM with salmon sperm DNA (SS-DNA) showed hypochromism trend which indicate intercalation mode of attachment and exhibited binding constant value 4.9 × 103 M−1 and 2.7 × 104 M−1 for SnTPP-Di-Tris and PolySnP@POM, respectively, referring that PolySnP@POM has more binding affinity than SnTPP-Di-Tris. Protein binding Study presented binding constant value (Kb) 3.09 × 104 M−1 and 1.30 × 104 M−1 for PolySnP@POM, and SnTPP-Di-Tris, correspondingly. Antibacterial activity results showed minor to significant activity. Furthermore, enhanced antibacterial activity of SnTPP-Di-Tris over its corresponding hybrid PolySnP@POM was observed because of lipophilic and more proliferating nature of SnTPP-Di-Tris.