Direct detection of solanesol in tobacco by ¹H and ¹³C magic angle spinning NMR

¹H and ¹³C NMR have been used to detect solanesol directly in tobacco without destroying or modifying the sample. Magic angle sample spinning was employed to remove the resonance line broadening due to variations of magnetic susceptibility within the sample. ¹³C line widths of ca . 10 Hz were obtained. The ¹H MAS spectrum of tobacco allows the solanesol signals to be resolved from the broad signal of exchangeable protons. ¹³C spin-lattice relaxation times (T₃) and nuclear Overhauser enhancements (NOE) of solanesol in chloroform solution, in intact tobacco, and as nest oil indicate that the polyisoprene chain motion in tobacco is restricted relative to the motion in solution but still sufficient to average out the dipolar couplings between protons and carbons. (author)