Glucuronide conjugates of cannabidiol (CBD), 7-hydroxy-CBD, propyl-CBD, cannabinol (CBN), 7-hydroxy-CBN, CBN-7-oic acid, propyl-CBN and cannabichromene were identified as major metabolites of CBD, CBN and their propyl homologs and of cannabichromene in mouse liver. Trace amounts of the glucuronide conjugates of .DELTA.1- and .DELTA.1(6)-tetrahydrocannabinol (THC) were also detected. Identification was made by combined GLC and mass spectrometric studies of the trimethylsilyl (TMS), d9-TMS and methyl ester-TMS derivatives of the glucuronides and the TMS derivatives of the product of the reduction of the metabolites with lithium aluminium deuteride.