 In this study, the resonance of one population of protons (1H) in an organic molecule was enhanced when a second distinct population of protons in the same organic molecule was saturated by RF irradiation.The application of the NOE was used by Anet and Bourn in 1965 to confirm the assignments of the NMR resonances for β,β-dimethylacrylic acid and dimethyl formamide showed that conformation and configuration information about organic molecules can be obtained.Bell and Saunders reported direct correlation between NOE enhancements and internuclear distances in 1970  while quantitative measurements of internuclear distances in molecules with three or more spins was reported by Schirmer et al.