For researchers, the complex and time-consuming process of isolating pure chemical compounds from a natural origin, such as plant extracts, for scientific analysis may be a thing of the past. 

Agriculture and Agri-Food Canada (AAFC) phytochemist Dr. Jason McCallum, and fellow AAFC scientist Dr. Chris Kirby, have developed a new, lightning-fast way to generate pure, plant-based compounds for analysis, aptly named Ultra-Micro-Scale-Fractionation  (UMSF). Traditional bioassay guided fractionation – a process to isolate a pure chemical agent from a natural origin, such as plant extracts – often takes many days to purify individual compounds and produces large volumes of waste.

With a background in nutri-science, McCallum has spent hundreds of hours in his lab separating various plant extracts into pure chemical compounds (natural products) through a method called high-performance liquid chromatography (HPLC). This method has been used since the 1980s to discover natural products, like penicillin, that may be applicable for research in the creation of new agriculture products (bio-pesticides, disease-resistant plant varieties) or pharmaceutical drugs and antibiotics.

McCallum and Kirby’s new UPLC (ultra-performance liquid chromatography) method is much faster than older HPLC techniques. Their idea, to speed up the fractionation process by modernizing the equipment used, led to the development of this new method that has exciting implications for researchers everywhere. To achieve their high-speed results, they integrated new fraction-collector and plate-dryer equipment to collect the pure chemical compounds.

The UPLC method only takes six to 10 minutes and uses five millilitres of solvent. Using this approach, pure natural products can be obtained from plant extracts in a single step – often a single leaf, flower or fruit provides enough extract to conduct the analysis. Not only does this speed up the process, it also reduces waste:

“Older purification methods produced large volumes of compounds for analysis, and for our purposes, we required only a fraction of that output,” says Dr. McCallum. “Our theory was simple – by reducing the scale of the device and materials used, we could decrease the time to complete analysis and reduce waste.”

“For researchers, UMSF will enable rapid discovery of new natural products that can be applicable to agriculture, nutri-science and pharmaceuticals,” explains Dr. McCallum.

“For researchers, UMSF will enable more rapid discovery of new natural products that can be applicable to agriculture, nutri-science and pharmaceuticals.”, says Dr. Jason McCallum, Phytochemist, Agriculture and Agri-Food Canada.

Dr. McCallum has been studying hops varieties since 2015, and in 2019 discovered some unique characteristics of Maritimes wild hops. These maritime-made flavours and aromas, like melon and cotton candy, make the future commercial release of these varieties highly anticipated among the hops-growing and brewing industries.

With the ability to complete analysis in a fraction of the time, McCallum decided to test the new UMSF method on a variety of plants available in his lab including Rocky Mountain Juniper berries, St. John’s Wort flowers, Nannyberry fruits, Bunchberry Dogwood fruits, Western Snowberry fruits, and Cascade hops cones.

He tested the effects of the above plant extracts, separated into pure chemical compounds by using UMSF, on brine shrimp. Brine shrimp is an established model organism used in research to look for anti-cancer and anti-insect activities in natural products. Through this research, Dr. McCallum noted that the Cascade hops variety may have implications for another industry – cancer research.

“Through UMSF, we’ve confirmed the anti-cancer activity of hops components in a multicellular organism (brine shrimp) for the first time.”, says Dr. Jason McCallum, Phytochemist, Agriculture and Agri-Food Canada.

“I was excited to discover that the hops extracts possessed high bioactivity with multiple beta acids identified as having anti-cancer (cytotoxic) activity,” says Dr. McCallum.

“Through UMSF, we’ve confirmed the anti-cancer activity of hops components in a multicellular organism (brine shrimp) for the first time.”

So, what does this mean for cancer researchers?  According to Dr. McCallum , it’s more confirmation that these biologically active beta acids from hops can destroy cancer cells.

“The mystery that cancer researchers will need to explore further is, how are these hops chemicals destroying cancer cells?”

Dr. McCallum is eager to try UMSF on new plant extracts in the pursuit of discovering natural products that may unlock new capabilities, from finding anti-cancer properties to potentially creating new bio-pesticides. Simply put, UPLC fractionation has the potential to put research development into hyperspeed.