South African Researchers Detect “Rare Compounds” In Cannabis Leaves
The leaves of cannabis plants are often considered to be waste by some cannabis cultivators and destroyed. However, recent research conducted in South Africa is shedding new light on why cannabis leaves may contain useful compounds.
Two researchers affiliated with the Department of Chemistry and Polymer Science at the University of Stellenbosch conducted a “comprehensive two-dimensional liquid chromatographic analysis of cannabis phenolics,” with their findings being published in the Journal of Chromatography A.
“Compared to the well-studied cannabinoids and terpenoids, characterization of the phenolic composition of Cannabis has received little attention.” the researchers stated about their investigation. “With studies reporting synergistic effects in Cannabis, the importance of investigating polyphenols in Cannabis is becoming more apparent.”
“We report an on-line comprehensive 2D HILIC × RP-LC method hyphenated to high resolution (HR) MS for the detailed characterization of polar phenolics in Cannabis inflorescence and leaf samples of three commercial strains.” the researchers wrote. “Optimal HILIC × RP-LC conditions were derived using an automated method optimization program, and provided excellent separation performance (peak capacity > 3000) and high orthogonality. Diode array and HR-MS data enabled tentative identification of 79 compounds, comprising mainly flavone and (hydroxy)cinnamic acid derivatives.”
“The presence of three C-glycosylated flavones, as well as several of their O-glycosylated derivatives, distinguished one of the strains from the other two. In the same strain, flavoalkaloids were detected, mainly in the leaf extracts. The structures of the alkaloid moieties could not be unambiguously assigned based on the available HR-MS data, but four classes of flavoalkaloids comprising 16 flavone derivates could be tentatively identified.” the researchers found.
“This is the first time that this relatively rare and chemically interesting class of compounds has been detected in Cannabis. These findings highlight the diversity of Cannabis, and the utility of HILIC × RP-LC-HR-MS for the in-depth study of its phenolic composition.” the researchers concluded.
The results of this study in South Africa demonstrate that while humans know more about the cannabis plant now than ever before, there is still a lot left to be discovered, and that is true for the leaves of cannabis plants just as much as it is for other parts of the plant.
“Our analysis again highlights the medicinal potential of cannabis plant material, currently regarded as waste. Cannabis exhibits a rich and unique non-cannabinoid phenolic profile, which could be relevant from a biomedical research perspective,” stated Prof. André de Villiers, one of the authors of the study.