Synthesis, biological evaluation and molecular docking studies of a new magnesium (II) porphyrin complex

Abstract

A new bioactive material of magnesium porphyrin complex [Mg(TPP)](H2O)2].2/3(2.2.2).1/3(Bz) (I), (TPP = meso-‑tetraphenylporphyrinato and (2.2.2) = cryptand, and Bz is benzene (C6H6)) has been synthesized and characterized by Single-crystal X-ray diffraction (SCXRD). The title compound crystallizes in trigonal crystal system in space group P-3. The magnesium ion is coordinated to four nitrogen atoms of the porphyrin core and two oxygen atoms of the axial ligands. The crystal packing is stabilized by inter-and intramolecular hydrogen bonds, and by weak C–H…Cg π interactions leading to a bi-dimensional network. In order to confirm the crystal structure, the photophysical properties have been evaluated by infrared (IR), proton nuclear magnetic resonance 1H NMR and UV–Vis spectroscopy. UV–Visible absorption spectrum of complex (I) displayed a red shifted Soret (429 nm) and Q (567 and 609 nm) bands due to the extended conjugation. The IR, and 1H NMR confirm the crystal structure. Finally, bioactivity investigations revealed that free porphyrin H2TPP, [Mg(TPP)] and complex (I) could be used as potential novel significant antibacterial agents. The docking of the free base porphyrins, metallated and the complex (I), in the active sites of bacterial proteins EEscherichia coli (1ECL) and Aspergillus Niger (3K4P) was carried out to detect the degree of antibacterial activity of recognition.