Lophine-cinnamoyl hybrids: Synthesis, photophysical properties and a spectroscopic and molecular dynamics approach towards interactions with bovine serum albumin

Abstract

Lophine and cinnamic acid derivatives have gained considerable attention due their chemical, biological and fluorescence emission properties. Herein we reported the synthesis of a new family of lophine-cinnamoyl hybrids connected by a methylene chain with two to nine carbon atoms. The hybrids show absorption in the ultraviolet and emission in the blue-violet region independent of the length of the alkyl chain spacer. Non-covalent interactions of the hybrids to bovine serum albumin (BSA) were investigated by UV–Vis absorption and fluorescence spectroscopy. Overall, the hybrids display moderate affinities for BSA (binding constants in the range 10–14 × 104 M−1) and can be effectively employed as protein probes using BSA as a model. The theoretical calculations showed preferential interactions of the hybrids with the binding pocket located near to Trp213 and the number of binding sites equal to 1 are in agreement with the experimental data obtained through the Stern-Volmer approach.