The New Cannabis? Scientists Find Cannabinoids in South African “Woolly Umbrella” Plant
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Scientists have discovered another plant that is able to produce cannabinoids, compounds that were previously thought to be exclusive to the cannabis plant.
In a new study, published in the journal Nature Plants, researchers using advanced imaging techniques and genetic sequencing data confirmed the presence of more than a dozen cannabinoids in the glandular trichomes of Helichrysum umbraculigerum, a South African plant better known as the “woolly umbrella”.
While the plant does not produce THC or CBD – the two major cannabinoids that cannabis is normally move coveted for – the researchers did find significant amounts of cannabigerolic acid (CBGA). This acidic cannabinoid is a precursor compound to THC and CBD, as well as many of the more minor cannabinoids that are of interest to the medical community, such as cannabigerol (CBG) and cannabichromene (CBC).
The researchers say that their findings, combined with woolly umbrella’s known fast growth rates and easy propagation, suggest that the plant could be another potentially commercially-viable source of bioactive cannabinoids for research and commercial use.
Woolly umbrella produces well-known cannabinoids
The woolly umbrella plant is a fast-growing perennial herb, commonly found in the regions between the Eastern Highlands of Zimbabwe and South Africa’s Eastern Cape. Named for its distinctive mustard-colored parasol-shaped flowers, the woolly umbrella is also known for its burning in traditional folk ceremonies to release intoxicating fumes.
When searching for what makes these fumes intoxicating more than 40 years ago, scientists identified traces of CBGA – the mother of cannabinoids – in the woolly umbrella plant. This discovery made the woolly umbrella the first non-cannabis plant species known to be capable of producing these compounds. However, a subsequent study was unable to replicate this result.
Now, armed with cutting-edge analytical chemistry techniques and genome sequencing data, researchers from the Weizmann Institute of Science set out to definitively confirm the presence or absence of these cannabinoids.
Using NMR spectroscopy, they detected and determined the precise structures of more than a dozen cannabinoids and related metabolites in H. umbraculigerum. While THC and CBD – the two major cannabinoids found in cannabis – were not seen in the plant, six of the cannabinoids found are identical to those seen in cannabis. These chemicals included CBGA, which was found in levels up to 4.3% dry weight in the plants’ leaves.
This is comparable to the levels typically measured in some cannabis chemotypes, the researchers say. As CBGA is a precursor molecule to the other classical cannabinoids that are of interest to researchers and the cannabis industry – including THC, CBD, CBG, CBC, and others – this may suggest that woolly umbrella could be a valuable alternative source of plant-based cannabinoid for the industry, especially in light of its fast growth and easy propagation.
Discovery could lead to new cannabinoid manufacturing processes
Using several high-resolution imaging technologies, the researchers observed that, like cannabis species, H. umbraculigerum produces and accumulates cannabinoids in the hair-like glandular trichomes found on the surface of the plant.
But unlike cannabis, where the flower buds are the main source of these cannabinoid-containing trichomes, the cannabinoids in the woolly umbrella found are largely concentrated on the plant’s leaves. This could be a commercial advantage for the plant, the researchers suggest, as it means less reliance on shorter-lived and comparatively harder-to-harvest flowers.
In addition, the researchers were able to trace the entire biochemical pathway involved in producing the cannabinoids in H. umbraculigerum. They found that this included three core cannabinoid synthesis enzymes, as well as two previously unknown types that are absent in traditional cannabis species and which can generate previously unreported cannabinoid structures.
The researchers say that they have already taken these insights a step further, having successfully generated these cannabinoid-making enzymes in tobacco plants. They have also demonstrated that these enzymes can be used to make certain cannabinoids in yeast, indicating a vast potential for future novel cannabinoid synthesis methods for research and industry applications.
“We have found a major new source of cannabinoids and developed tools for their sustained production, which can help explore their enormous therapeutic potential,” said lead study author Dr. Shirley (Paula) Berman.
The researchers do not know – in an evolutionary sense – why the woolly umbrella plant is capable of making cannabinoids, but they theorize that, since two unique plant species both independently evolved this ability, it’s possible cannabinoids could offer some defensive advantage against animals or other hazards.
“The fact that in the course of evolution two genetically unrelated plants independently developed the ability to make cannabinoids suggests that these compounds perform important ecological functions,” said Asaph Aharoni, a professor who heads the Department of Plant and Environmental Sciences at the Weizmann Institute of Science. “More research is needed to determine what these functions are.”
The research team believes that this discovery could lead to the engineering of brand-new cannabinoids that do not currently exist in nature. Such designer compounds could lead to cannabinoids that bind to the human cannabinoid receptors in unique ways to achieve different therapeutic effects, they suggest. On a more short-term basis, the researchers say they are interested in further studying the new cannabinoids that were identified in this study.
“The next exciting step would be to determine the properties of the more than 30 new cannabinoids we’ve discovered, and then to see what therapeutic uses they might have,” Berman said.