Digital NMR Profiles as Building Blocks: Assembling ¹H Fingerprints of Steviol Glycosides

Abstract

This report describes a fragment-based approach to the examination of congeneric organic compounds by NMR spectroscopy. The method combines the classic interpretation of 1D- and 2D-NMR data sets with contemporary computer-assisted NMR analysis. Characteristic NMR profiles of key structural motifs were generated by ¹H iterative full spin analysis and then joined together as building blocks to recreate the ¹H NMR spectra of increasingly complex molecules. To illustrate the methodology described, a comprehensive analysis of steviol (<b>1</b>), seven steviol glycosides (<b>2</b>–<b>8</b>) and two structurally related isosteviol compounds (<b>9</b>, <b>10</b>) was carried out. The study also assessed the potential impact of this method on relevant aspects of natural product research including structural verification, chemical dereplication, and mixture analysis