Quantum Mechanics-Based Structure Analysis of Cyclic Monoterpene Glycosides from Rhodiola Rosea
NMR- and MS-guided metabolomic mining for new phytoconstituents from a widely used dietary supplement, <i>Rhodiola rosea</i>, yielded two new (+)-myrtenol glycosides, <b>1</b> and <b>2</b>, and two new cuminol glycosides (<b>3</b> and <b>4</b>), along with three known analogues (<b>5</b>–<b>7</b>). The structures of the new compounds were determined by extensive spectroscopic analysis. Quantum Mechanics-driven <sup>1</sup>H iterative Full Spin Analysis (QM-HiFSA) decoded the spatial arrangement of the methyl groups in <b>1</b> and <b>2</b>, as well as other features not recognizable by conventional methods, including higher order spin-coupling effects. The application of QM-HiFSA will provide a definitive reference point for future phytochemical and biological studies of <i>R. rosea</i> as a resilience botanical. Application of a new NMR data analysis software package, CT, for QM-based iteration of NMR spectra is also discussed.