By Alan Benesi
A library of NMR spectra of pure compounds found in cannabis and cannabis extracts, in particular 2D H1-C13 HSQC and HMBC spectra, will be obtained under standard conditions. These will be used to characterize DEA-approved cannabis samples from different cannabis strains grown under different conditions at the NIDA cannabis facility at the University of Mississippi. Experiments will be carried out on an upgraded 800 MHz NMR spectrometer at the University of California, Irvine.
The H1-C13 2D spectrum of each pure compound will provide a unique “atomic fingerprint” for that compound. Each hydrogen and carbon atom in the chemical structure of the pure compound will be identified and associated with a “spot” in its atomic fingerprint. This knowledge will allow the identification and quantification of components in cannabis and cannabis products. The atomic fingerprint of such mixtures provides in one rectangular map a unique summary of every component in the mixture. Moreover, the atomic fingerprints can be used to reveal “outlier spots” from unwanted metablolites or foreign substances such as drugs, herbicides, and pesticides.
The following experiments will be performed on the UCI 800 MHz NMR spectrometer covering the spectral range of 13 ppm to -1 ppm for H1 and 240 ppm to -10 ppm for C13: i. H1 1D, ii. C13 1D (H1 decoupled), iii. C13 1D DEPT, iv.H1-C13 2D HSQC, v. H1-C13 2D HMBC, vi. 2D H1-H1 COSY or TOCSY, vii. 3D diffusion separated H1-C13 HSQC and/or H1-H1 COSY. The data will be processed, plotted, and analyzed using an NMR software package such as Bruker Topspin. Each carbon and hydrogen atom in the chemical structure of the pure sample will be identified and the spectra and assignment tables will be published.
Each sample will also be analyzed with GC and HPLC.