A density functional study of 15N chemical shielding tensors in quinolines

DFT calculations were carried out to characterize the 15N shielding tensors in quinolines. This computational study is intended to shed light on the differences between two groups of quinolines: series A (7-chloro 4-aminoalkyls quinolines) and series B (quinolines, 3-, 5-, 6-, 8-amino quinolines and 4,8-dichloro quinoline). Unlike the quinolines in series B, the series A quinolines show considerable β-hematin inhibition activity which is essential for quinoline-based drugs. The results show that the substitution position significantly affects the σ11 and σ22 components of 15N shielding tensors of quinolines. The 15N shielding components are noticeably different for the two series and can be related to their ability to interact with hematin.