Synthesis, Structural Characterization and Investigation of DNA/BSA Binding Properties of a Homo-disulphide Schiff Base Compound Carrying Oxo Propargyl Group

In this work, a new homo-disulphide Schiff base compound (HDSB) was prepared and its structure was characterised by common spectroscopic and analytical methods. The compound was obatined from the condensation reaction of 2-aminothiophenol and 2-hydroxy-4-(prop-2-yn-1-yloxy)benzaldehyde in benzene. In the reaction, both Schiff base condensation and oxidation of thiols into disulphide formed. The isolated compound was structurally characterized by single crystal X-ray diffraction experiment. The homo-disulphide Schiff base compound (HDSB) was screened for its DNA/BSA binding properties using UV-Vis absorption and emission spectral studies. The compound showed considerable binding affinity to double-stranded fish sperm DNA (FSds-DNA) with binding constant of 4.1 × 104 M-1. Spectral measurements suggest that HDSB interacts with DNA in a minor groove binding mode. The compound also showed binding properties towards BSA (bovine serum albumin). The incremental addition of HDSB to the BSA solution resulted in a significant decrease in the characteristic emission band of BSA in the range of 320-500 nm (λexc: 280 nm) showing the binding interactions between HDSB and BSA.