Forensic Sci Int. 2022 Apr 14;335:111309. doi: 10.1016/j.forsciint.2022.111309. Online ahead of print.
Cannabis cultivation for medical purposes in Brazil has been increased in the last years. While cannabis crops are prohibited, hundreds patients have been granted with judicial authorizations and there is little information about the cultivation conditions, yields and chemical profiles of the plants. Cannabis plants contain hundreds of compounds, with cannabinoids and terpenes the main drivers of their toxicological and pharmacological properties. Besides the cannabinoids, terpene contents are useful for the chemotaxonomic classification of different varieties, and their role in forensic analyses should be further delineated. The present study monitored cannabis crops of fifteen participants who were granted special licenses by the Brazilian Courts in Rio de Janeiro and São Paulo. The cultivation conditions were monitored and five cannabinoids (tetrahydrocannabinol acid-THCA, tetrahydrocannabinol-THC, cannabidiolic acid-CBDA, cannabidiol-CBD and cannabinol-CBN) and nineteen terpenes were quantified in cannabis flowers. The total grow cycle of thirty-five cannabis plants ranged from 10 to 24 weeks. The dry flower yields ranged 22-90 g per plant. Most cannabis specimens were CBD-rich varieties (CBD levels from 1.6% to 16.7%, and THC levels from 0.0% to 2.6%, n = 22) used to treat epileptic patients. The THC-rich varieties contained CBD levels ranging from 0.03% to 0.8%, and THC levels from 0.7% to 20.1%, n = 11. Fewer of the samples contained THC:CBD ratios of approximately 1:1 (CBD levels of 3.3-3.8% and THC levels of 2.2-3.7%, n = 2). The most abundant terpenes in the cannabis flowers were beta-caryophyllene, alpha-humulene, guaiol and alpha-bisabolol. CBD-rich varieties showed significant higher levels of beta-caryophyllene and alpha-humulene in comparison with THC-rich varieties. Overall, the study herein provides data concerning medical cannabis crops grown in a region of Brazil that not only guide individual medical cannabis cultivation methods but also aid forensic analyses.