Fast Determination of ¹³C NMR Chemical Shifts Using Artificial Neural Networks

Abstract

Nine different artificial neural networks were trained with the spherically encoded chemical environments of more than 500000 carbon atoms to predict their 13C NMR chemical shifts. Based on these results the PC-program "C_shift" was developed which allows the calculation of the 13C NMR spectra of any proposed molecular structure consisting of the covalently bonded elements C, H, N, O, P, S and the halogens. Results were obtained with a mean deviation as low as 1.8 ppm; this accuracy is equivalent to a determination on the basis of a large database but, in a time as short as known from increment calculations, was demonstrated exemplary using the natural agent epothilone A. The artificial neural networks allow simultaneously a precise and fast prediction of a large number of 13C NMR spectra, as needed for high throughput NMR and screening of a substance or spectra libraries.

Empirical and DFT GIAO quantum‐mechanical methods of 13C chemical shifts prediction: competitors or collaborators?

“…[1 -4] The programs [5 -9] utilizing a fragmental approach and HOSE codes [10] as well as efficient artificial neural net algorithms (NN) were developed. [11,12] These algorithms are based on empirical methods, run fully automatically and require no user intervention. As the programs were required by expert systems for the purpose of computer-aided structure elucidation (CASE), [13] they were implemented into the most advanced CASE systems.…”

Prediction of Melting Point for Drug-like Compounds Using Principal Component-Genetic Algorithm-Artificial Neural Network

“…For these reasons in recent years, ANNs have been applied to a wide variety of chemical problems. [33][34][35][36][37][38][39][40][41][42] Very recently, QSPR models have been applied for prediction of the melting point of 323 set of drug-like compounds. 43 Ability of these models for prediction of the melting point is poor (for example, root-mean square error of the models is approximately 40.7 ºC).…”

NMR Spectroscopy as a Tool for the Determination of Structure and Dynamics of Molecules

“…There are several tools available to do this. This includes the use of DFT [23], empirical methods such as chemical-shift calculation [24], and neuronal networks [25]. The latter approach requires a large set of molecules with known structures available, on which the network is trained.…”