Improvement in Resolution with Nonlinear Methods Applied to NMR Signals from Macromolecules

Abstract

Spectral estimators alternative to the Fast Fourier Transform have elicited a great deal of interest for performing the spectral anaylsis of NMR signals in time domain. In our approach, we used Prony’s method, in connection with the covariance algorithm, to calculate the autoregressive coefficients. The main problem in the use of this method is the determination of the model order p. We have examined the behavior of the residuals as a function of p and then we studied the stability of the result around relative minima. We have applied this method to the 31P NMR signals from the antiviral drug ara-AMP conjugated to human lactosaminated albulmin as hepatotropic carrier, obtaining very high resolution spectra.