Executive Summary: Cannflavin (flavonoid) extraction from hemp: proof of principle

Summary of Project and Key Findings:
Hemp seed production produces a significant amount of plant biomass that cannot currently be used due to regulations restricting the use of leaves and flowers and the lack of identified value streams. Cannflavins are flavonoids (not a cannabinoids, despite their names) unique to the cannabis plant, recognised as having significant pain-relieving properties and typically present only in low concentrations. There are two related compounds, Cannflavin A and Cannflavin B present in cannabis plants.

The project evaluated the use of cannabis waste (from both hemp seed and fibre crops) to create further high-value medicinal plant extracts for export markets. Hemp flower and sprout material was extracted and analysed for the presence of the high value flavonoids cannflavins.

An extraction and LCMS method was developed to extract, detect, and semi-quantify cannflavins in hemp flower and sprout material. Both cannflavins were only found in notable amounts in hemp flower samples, and of these only in significant amounts in the hemp leaves and combined leaves and flowers samples. Therefore, it can be presumed that the cannflavins are mainly found in the leaves of mature plants. Neither of the cannflavins were detected in quantifiable amounts in any of the sprout samples. It could be worthwhile analysing mature hemp leaves for cannflavins in the future, but that is out of the scope of this project. This data suggests that hemp sprouts are not a viable source of cannflavins.

The use of molecularly imprinted polymers (MIPs) was investigated as a method to part-purify the extracts, with promising results.