A recent study has conducted one of the most extensive investigations to date on the chemical compounds responsible for the distinct “skunk-like” smell of cannabis. The findings reveal the presence of a previously unknown family of sulfur compounds that contribute to the odor, and these molecules share chemical similarities with aroma compounds found in garlic.
While current cannabis research often focuses on understanding the effects of cannabinoids like THC and CBD, there are numerous other molecules present in this complex plant. This study specifically aimed to uncover the chemical source of cannabis’ unique and pungent aroma.
Cannabis contains hundreds of different aroma compounds, many of which belong to a class called terpenes, known for their characteristic plant smells such as pine or lavender. Breeders experiment with different terpene concentrations to develop hybrid strains with distinct scents. While terpenes have been previously hypothesized to be responsible for the cannabis smell, difficulties in analyzing all potential aroma compounds have limited comprehensive studies.
To overcome these challenges, the researchers employed a custom-built comprehensive 2-dimensional gas chromatography (2DGC) system with multiple detectors to analyze cannabis. They specifically focused on volatile sulfur compounds (VSCs), which are organic compounds containing sulfur that are associated with pungent odors in other plants like hops, garlic, and skunks. Given that the pungent aroma of cannabis is colloquially referred to as “skunk,” the study aimed to identify which VSCs in the plant are linked to this distinct smell.
The use of multiple detectors and 2DGC allowed the researchers to analyze the data and identify correlations between specific compounds and the aromas of different cannabis strains. Lead author Iain Oswald explains that this approach conclusively established a connection between this new family of VSCs in cannabis and its pungent aroma.
The study identified several previously unidentified VSCs in cannabis, and analysis of particularly pungent strains revealed a direct association between higher concentrations of these VSCs and “skunk-like” scents. The researchers also found a remarkable chemical similarity between these newly discovered cannabis VSCs and some VSCs found in garlic. Previous research has linked certain health benefits of garlic to these specific VSCs, suggesting potential medicinal properties of the newly identified cannabis VSCs.
The study demonstrated that although VSCs are highly volatile, they can remain present in certain extracts if processed correctly, with varying concentrations. Additionally, the concentration of VSCs was found to be highest at the end of the cannabis plant’s growth cycle, peaking after an 11-day curing process following harvest. However, VSC levels decreased significantly as the cured plant was stored, dropping significantly after ten days. These findings provide valuable insights to producers aiming to maximize VSC content in future cannabis products.
The research offers strong evidence regarding the chemical origins of cannabis’ distinct pungent odor and suggests potential avenues for further research into the medicinal benefits of these newly discovered compounds.
The study was published in the journal ACS Omega.