Total lineshape analysis of high-resolution NMR spectra powered by simulated annealing

ANATOLIA: NMR software for spectral analysis of total lineshape

“…Thus, it is a common practice to perform additional optimizations with sign alternation of all the J-couplings whose signs are not known. [6] In the case of styrene, we performed 512 calculations varying the signs of 9 long-range J-couplings. The results are summarized in Table 1.…”

“…[1][2][3] The spin-spin J-coupling constants provide essential information on molecular structure, stereochemistry, and conformation, but determination of their values can be rather complicated. [4][5][6] Knowledge of J-couplings has recently found important applications for creating of long-lived states in multiple spin systems [7] and for the description of SABRE hyperpolarisation dependency on the magnetic field. [8] Development of new experimental approaches to measure J-couplings is an actively growing area.…”

“…We recently found that the number of local minima could reach thousands even for relatively small spin systems. [6] Using a Monte Carlo method to find a global minimum is an effective approach to overcome this problem, however, it requires significant computational resources and can be efficiently realized using a computer cluster. [6,17] In this tutorial we discuss another concept, well suitable for a personal computer, which is the broadening approach.…”

“…[6] Using a Monte Carlo method to find a global minimum is an effective approach to overcome this problem, however, it requires significant computational resources and can be efficiently realized using a computer cluster. [6,17] In this tutorial we discuss another concept, well suitable for a personal computer, which is the broadening approach. [4,5,18] An idea behind this method is to apply additional broadening to experimental and theoretical spectra before parameters optimization, which leads to merging of the neighboring spectral lines and, therefore, eliminates most of the local minima.…”

Spin System Modeling of Nuclear Magnetic Resonance Spectra for Applications in Metabolomics and Small Molecule Screening

“…By broadening the peak line width, these methods attempt to minimize the L2 distance (mean squared error) between the experimental and the simulated spectrum of a compound. Cheshkov et al 39 have discussed the problems with this methodology and, to address some of its shortcomings, have introduced a simulated annealing approach for optimizing the L 2 distance function. However, because the objective of this method is to approximate correct line shape parameters, the algorithm requires precise initial specification of the spin system matrix, and the heuristics introduced in the approach may converge to multiple local minima making it challenging to identify the correct spin system matrix.…”