Cannabis ‐ from cultivar to chemovar

Abstract

The medicinal use of Cannabis is increasing as countries worldwide are setting up official programs to provide patients with access to safe sources of medicinal-grade Cannabis. An important question that remains to be answered is which of the many varieties of Cannabis should be made available for medicinal use. Drug varieties of Cannabis are commonly distinguished through the use of popular names, with a major distinction being made between Indica and Sativa types. Although more than 700 different cultivars have already been described, it is unclear whether such classification reflects any relevant differences in chemical composition. Some attempts have been made to classify Cannabis varieties based on chemical composition, but they have mainly been useful for forensic applications, distinguishing drug varieties, with high THC content, from the non-drug hemp varieties. The biologically active terpenoids have not been included in these approaches. For a clearer understanding of the medicinal properties of the Cannabis plant, a better classification system, based on a range of potentially active constituents, is needed. The cannabinoids and terpenoids, present in high concentrations in Cannabis flowers, are the main candidates. In this study, we compared cultivars obtained from multiple sources. Based on the analysis of 28 major compounds present in these samples, followed by principal component analysis (PCA) of the quantitative data, we were able to identify the Cannabis constituents that defined the samples into distinct chemovar groups. The study indicates the usefulness of a PCA approach for chemotaxonomic classification of Cannabis varieties.

Cannabinoids and Terpenes as Chemotaxonomic Markers in Cannabis

“…The loading plot reveals that this group is characterized by relatively high amounts of terpinolene, α-terpinene and α-phellandrene. It is worth noting that the monoterpenoid profiles of these strains were similar to strains described as 'sativa' in other studies [14,15,20]. Plotting of additional principal components did not reveal any new groupings.…”

Evolution and Classification of Cannabis sativa (Marijuana, Hemp) in Relation to Human Utilization

“…Increasingly, strains with alleged percentages of "sativa" and "indica" are being sold. There are varying descriptions in the literature about their contrasting psychological effects (see, for example, Hazekamp and Fischedick (2012) and Smith (2012); also see Table 1). These descriptions generally credit the high-THC sativa type with producing a more euphoric "high," and the lower-THC type with substantial CBD with producing a more attenuated experience, consistent with how CBD in marijuana substantially alters the effects of THC, as explained in the following subsection.…”

Classification of Cannabis Cultivars Marketed in Canada for Medical Purposes by Quantification of Cannabinoids and Terpenes Using HPLC-DAD and GC-MS

“…The second, a chemotaxonomic perspective, describes five chemotypes (chemical phenotypes) based on the ratio of two major cannabinoids THC and CBD, which is decided by their corresponding allelic loci [14][15][16][17][18][19][20][21]. Recently, a third perspective seeks to categorize cultivars based on both cannabinoids and terpenes for drug standardization and clinical research purposes [22,23]. However, there is no currently available systematic classification covering the majority of commercially available cultivars.…”