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, Rhodiola rosea, yielded two new (+)-myrtenol glycosides, 1 and 2, and two new cuminol glycosides (3 and 4), along with three known analogues (5–7). The structures of the new compounds were determined by extensive spectroscopic analysis. Quantum Mechanics-driven ¹H iterative Full Spin Analysis (QM-HiFSA) decoded the spatial arrangement of the methyl groups in 1 and 2, 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 R. rosea as a resilience botanical. Application of a new NMR data analysis software package, CT, for QM-based iteration of NMR spectra is also discussed.