Isolation and Characterization of Impurities in Commercially Marketed Delta 8-THC Products

Qualitative analysis of several commercial products containing A8-tetrahydrocannabinol (A8-THC) as a major component using GC-MS resulted in the identification of several impurities along with A8-THC. In an attempt to isolate and identify these impurities, a commercial A8-THC distillate was selected for the isolation work. Eleven impurities were isolated using a variety of chromatographic techniques, and their chemical structures were determined. These include A4,8-iso-tetrahydrocan-nabinol (1), A4-iso-tetrahydrocannabinol (2), A8-cis-iso-tetrahy-drocannabinol (3), 4,8-epoxy-iso-tetrahydrocannabinol (4), 8hydroxy-iso-tetrahydrocannabinol (5), 9 beta-hydroxyhexahydrocan-nabinol (6), 9 alpha-hydroxyhexa-hydrocannabinol (7), iso-tetrahydrocannabifuran (8), cannabicitran (CBT, 9), olivetol (10), and A9-THC (11). The chemical structures of the purified compounds were determined using several spectroscopic methods, including 1D (1H, 13C, and DEPT-135) and 2D (COSY, HMQC, HMBC, and NOESY) NMR, LC -MS, and GC-MS. Other naturally occurring cannabinoids and impurities were also identified in GC-MS chromatograms but were not isolated. These were cannabidiol (CBD, 12), cannabinol (CBN, 13), hexahydrocannabinol (HHC, 14), and A8-tetrahydrocannabivarin (A8-THCV, 15). The chemical structure of A8-THCV (15), for which a standard was not available, was confirmed by partial synthesis and NMR analysis. This is the first report for many of the above compounds as well as A8-THCV as impurities in A8-THC products.