The story of cannabicyclol (CBL) begins in the mid-20th century, a period when cannabis research was slowly emerging from obscurity and entering the realm of modern chemistry. CBL, one of the lesser-known cannabinoids, was identified during a time when scientists were just beginning to unravel the molecular puzzle of the cannabis plant. The early discovery of CBL stands as a testament to the persistence of researchers who worked under challenging legal and scientific conditions to decode the plant’s chemical secrets.
The Birth of Cannabinoid Chemistry
The foundation for CBL’s discovery was laid by a handful of pioneering chemists who first identified and isolated cannabinoids from cannabis extracts. In the 1940s, Roger Adams, an American organic chemist at the University of Illinois, was among the first to successfully isolate cannabidiol (CBD) and cannabinol (CBN), both of which paved the way for identifying other compounds like CBL. Adams’ research helped establish techniques such as chromatography and distillation that would later prove crucial in separating individual cannabinoids from the plant’s complex mixture of chemicals.
Around the same time, another key figure—British chemist Alexander Todd (later known as Lord Todd)—was exploring the structural chemistry of natural products, including cannabinoids. Todd’s group contributed to the understanding of the molecular frameworks of these compounds and introduced improved methods for identifying their ring structures. His Nobel Prize–winning work in nucleotides and natural products indirectly influenced the field of cannabis chemistry by refining how scientists analyzed organic molecules.
From Cannabichromene to Cannabicyclol
CBL’s discovery can be traced to the transformation of another cannabinoid: cannabichromene (CBC). Researchers noticed that under the influence of light and heat, CBC gradually converted into a different, more stable compound—what was later identified as cannabicyclol. This photochemical transformation was first documented in the late 1960s by Israeli chemist Yechiel Gaoni and his colleague Raphael Mechoulam, a name now synonymous with cannabis science.
Working at the Hebrew University of Jerusalem, Mechoulam and Gaoni used advanced spectroscopic methods to map the molecular structure of numerous cannabinoids, including THC, CBD, and eventually CBL. Their meticulous approach combined organic synthesis with chromatography to isolate individual molecules and determine their exact chemical structures. It was during this process that CBL’s non-psychoactive, photo-derived nature was recognized—a byproduct of the natural aging and oxidation of other cannabinoids.
The Legacy of Early Cannabis Chemists
What made these discoveries extraordinary was not just the identification of CBL but the broader understanding of cannabinoid conversion. Mechoulam’s lab demonstrated that cannabinoids are dynamic molecules, capable of changing form through exposure to environmental factors. This insight remains foundational to modern cannabis science, influencing how researchers store, process, and extract cannabinoids today.
The early chemists who studied CBL operated with limited tools and faced significant legal and cultural barriers. Their work predated the global wave of cannabis reform and required a balance of scientific curiosity and discretion. Yet, their findings—spanning from Adams’ early extractions to Mechoulam’s structural mapping—helped create the modern framework for studying cannabinoids.
A Foundation for the Future
Today, researchers continue to build upon the groundwork laid by these scientific pioneers. CBL is being revisited for its potential biological activity and stability, especially compared to other minor cannabinoids. The collective efforts of Adams, Todd, Mechoulam, and their contemporaries highlight how the curiosity of a few scientists half a century ago still drives discovery in cannabinoid chemistry. Their work not only identified CBL but also transformed how the world views the chemical complexity of the cannabis plant—a journey that continues to unfold in laboratories worldwide.