Abstrax, known for the study and production of cannabis and botanically derived terpenes, has released a study pinpointing the chemical origins of the “skunky, gasoline” scent and flavors responsible for specific cannabis cultivars in the American Chemical Society journal ACS Omega.
While terpenes are usually associated with the scent of cannabis, there is no combination of these compounds that can generate the scent. Recently, T.J. Martin of Abstrax lead a team to discover a new family of compounds responsible for this scent.¹ Using 2-dimensional gas chromatography (2DGC) and mass spectrometry, flame ionization detection and sulfur chemiluminescence, they discovered key volatile sulfur compounds (VSCs)—organic compounds containing sulfur—that directly correlate to the pungent aroma of cannabis. This new family of compounds includes thiols, sulfides and even disulfides, each were contributing to the characteristic skunk-like aroma. When coupled with the other aroma compounds such as terpenes, they combined to generate the scent of cannabis.
The study results provide a starting point for further research to be conducted that will be multidisciplinary in nature. For instance, the realization that certain cultivars may produce these compounds, while others do not, provides an opportunity to determine if this is due to genetic differences or otherwise. Bacio Gelato, which is a cultivar first bred by co-author Mario Guzman and has the highest concentration of VSCs measured in cannabis, may have genetic differences from the cultivar Black Jack, which had no measurable VSCs.
Another result from the study was that these compounds can translate from the flower state to extracts such as butane hash oil (BHO), a popular cannabis concentrate found in vapes.
Lastly, the study measured VSCs as a function of plant growth. The researchers found that the concentrations of these compounds increase substantially at the end of the plant’s growth and reach a maximum immediately after the curing process. Surprisingly, the concentrations of most VSCs dropped substantially after even just a week of storage.
Dr. Iain Oswald, the lead author of the study, said, “The combination of multiple detectors, in tandem with 2DGC to analyze cannabis, gave us the tools needed to parse through data and identify trends between certain compounds and the aromas of various cannabis cultivars. Our data conclusively establishes a link between this new family of VSCs in cannabis and its pungent aroma.”
Co-author Mario Guzman said, “This study really opened my eyes. It confirmed everything I had thought about some cultivars I have bred—that they are some of the most pungent and medicinal on the market. These compounds are the reason Gelato and subsequent crosses are some of the most highly sought after out there.”
Co-author Josh Del Rosso, the originator of OG Kush, said, “I have suspected for years now that we were missing something in our understanding of this plant. Although terpenes have been hailed as the major source of the pungent scent of cannabis, we now know that it is this new class of VSCs.”
Kevin Koby, CSO of Abstrax, said, “These results prove that cannabis producers are racing against time when it comes to getting quality products into customers’ hands. Hopefully our results will establish a new standard for cultivators and distributors to help preserve and protect these key compounds — regardless of the rigors of processing, packaging, and time on shelf. Most importantly, it will help brands maximize their products and literally push cannabis quality to the next level.”
¹Oswald, I. W. H.; Ojeda, M. A.; Pobanz, R. J.; Koby, K. A.; Buchanan, A. J.; Del Rosso, J.; Guzman, M. A.; Martin, T. J. Identification of New Family of Prenylated Volatile Sulfur Compounds in Cannabis Revealed by Comprehensive Two-Dimensional Gas Chromatography. ACS Omega. 2021, Article ASAP.