Adsorption and Self-Aggregation of Chiral [5]-Aza[6]helicenes on DNA Architecture: A Molecular Dynamics Study

Abstract

Helicenes are an extremely interesting class of conjugated molecules without asymmetric carbon atoms but with intrinsic chirality. These molecules can interact with double-stranded chiral B-DNA architecture, modifying after their adsorption the hydrophilicity exposed by DNA to the biological environment. They also form ordered structures due to self-aggregation processes with possible different light emissions. Following initial studies based on molecular mechanics (MM) and molecular dynamics (MD) simulations regarding the adsorption and self-aggregation process of 5-aza[5]helicenes on double-stranded B-DNA, this theoretical work investigates the interaction between ( M )- and ( P )-5-aza[6]helicenes with double-helix DNA. Initially, the interaction of the pure single enantiomer with DNA is studied. Possible preferential absorption in minor or major grooves can occur. Afterward, the interaction of enantiopure compounds ( M )- and ( P )-5-aza[6]helicenes, potentially occurring in a racemic mixture at different concentrations, was investigated, taking into consideration both competitive adsorption on DNA and the possible helicenes’ self-aggregation process. The structural selectivity of DNA binding and the role of helicene concentration in adsorption and the self-aggregation process are interesting. In addition, the ability to form ordered structures on DNA that follow its chiral architecture, thanks to favorable van der Waals intermolecular interactions, is curious.

Hybrid Organic–Inorganic Biomaterials as Drug Delivery Systems: A Molecular Dynamics Study of Quercetin Adsorption on Amorphous Silica Surfaces

“…All these theoretical results agree with the experimental data [92][93][94][95]. Possible new classes of hydrophobic drug carriers that can adsorb on the chiral DNA structure are currently being studied [99,100]. Interestingly, using MM/MD methods, the possible slower or faster release of drugs adhered and dispersed in nano aggregates or on a solid silica surface for their solubilization may be related to the strength of intermolecular interaction [95,98] as in the present work.…”