Interpretation of 2-Dimensional NMR spectra of small molecules

Abstract

Nuclear Magnetic Resonance (NMR) spectroscopy has had an enormous effect in numerous areas of chemistry, biology, and medicine. Nuclear Magnetic Resonance (NMR) Spectroscopy is a unique analytical technique that permits us to explore the structural information from one and two-dimensional NMR techniques available. In this thesis, we deduce the structural information about Quercetin and Flurbiprofen drug molecules with one-dimensional and two- dimensional NMR spectroscopy. The origin of chemical shifts, coupling constants, Chemical equivalence, one-dimensional and two- dimensional NMR (Correlated spectroscopy and Heteronuclear single quantum correlation spectroscopy) will be discussed, and their relation to the molecular structure will be provided. 1-D NMR spectroscopy us provide information about electron density around different atoms in molecules by chemical shift values. COSY (correlation spectroscopy) and HSQC (Heteronuclear single quantum correlation), the two 2-D NMR experiments, are performed to obtain the structural information of quercetin and flurbiprofen drug molecules. Through two-dimensional NMR spectroscopy, we obtain the information of spin interactions of homonuclear atoms in a molecule. The heteronuclear single quantum correlation experiment tells us about the interaction between the spins of heteronuclear atoms in the molecule. By seeing the correlation between homonuclear atoms and heteronuclear atoms from the two-dimensional COSY and HSQC experiment, and also from chemical shifts from one-dimensional proton NMR spectrum and carbon-13 NMR spectrum, we deduce the structural information about quercetin and flurbiprofen drug molecules.