Exploring the biophysical interaction of 3-pentadecylphenol with the head group region of a lipid membrane using fisetin as an interfacial membrane probe

Abstract

3-Pentadecylphenol (PDP) is a phenolic lipid easily available from natural sources. This compound has different pharmacological, biological and industrial applications. A molecular level understanding on the membrane modification properties of PDP on the dipalmitoylphosphatidylcholine (DPPC) bilayer has been carried out using fisetin as a sensitive interfacial head group region membrane probe. Membrane-inserted fisetin shows sensitive variation in its fluorescence properties (fluorescence intensity, lifetime, and anisotropy) with variation in the PDP concentration at the interfacial region of the lipid bilayer membrane. The formation of a mixed lipid system (i.e., DPPC + PDP) at a higher mol% of PDP (above 20 mol%) is responsible for the physico-chemical changes of the lipid bilayer membrane. The intrinsic fluorescence anisotropy data of PDP are also sensitive towards the membrane organizational changes of the DPPC lipid bilayer. The sensitivity of fisetin at the head group region of lipid membranes demonstrates that the alteration of bilayer properties is primarily caused by the abundance of the large phenolic headgroup.