Cannabis: From Cultivar to Chemovar II-A Metabolomics Approach to Cannabis Classification

Introduction: There is a large disparity between the "cultural" language used by patients using cannabis for self-medication and the "chemical" language applied by scientists to get a deeper understanding of cannabis effects in laboratory and clinical studies. The distinction between Sativa and Indica types of cannabis, and the different biological effects associated with them, is a major example of this. Despite the widespread use of cannabis by self-medicating patients, scientific studies are yet to identify the biochemical markers that can sufficiently explain differences between cannabis varieties. Methods: A metabolomics approach, combining detailed chemical composition data with cultural information available for a wide range of cannabis samples, can help to bridge the existing gap between scientists and patients. Such an approach could be helpful for decision-making, for example, when identifying which varieties of cannabis should be made legally available under national medicinal cannabis programs. In our study, we analyzed 460 cannabis accessions obtained from multiple sources in The Netherlands, including hemp- and drug-type cannabis. Results: Based on gas chromatography analysis of 44 major terpenes and cannabinoids present in these samples, followed by Multivariate Data Analysis of the resulting chromatographic data, we were able to identify the cannabis constituents that may act as markers for distinction between Indica and Sativa. This information was subsequently used to map the current chemical diversity of cannabis products available within the Dutch medicinal cannabis program, and to introduce a new variety missing from the existing product range. Conclusion: This study represents the analysis of the widest range of cannabis constituents published to date. Our results indicate the usefulness of a metabolomics approach for chemotaxonomic mapping of cannabis varieties for medical use.