An alternative scheme for the multiplexed acquisition of 1D and 2D NMR spectra

Abstract

Spin system selective 1D 1H, 2D DQF-COSY and 2D HSQC NMR spectra were recorded in order to fully assign the 1H and 13C 1D NMR spectra of an asymmetrical β-cyclodextrin derivative. Instead of individually accessing the seven sugar anomeric protons by means of long multiplet selective pulses, only short region selective pulses were used. The simultaneously selected anomeric protons were differentiated by allowing their magnetization to evolve under the sole effect of the chemical shift interaction. In each experiment, the seven recorded spectra were linear combinations of the seven desired ones. The combination coefficients were measured and used to obtain almost perfectly separated sugar unit sub-spectra. This multiplexed acquisition scheme resulted in a time gain factor of about 2.