How One Professor Is Using Colorimetric Analysis to Broaden Cannabis Research

September 9, 2019

Health, wellness, and pharmacological benefits put cannabis on the map, but the industry suffers from a lack of transparency, limited human clinical studies, and regulatory confusion and contradictions. And although analytical technology has broadened scientists’ ability to identify and quantify different types of cannabinoids, Dr. Andrea Holmes—professor of chemistry at Doane University in Crete, Nebraska, and the chief growth officer of Precision Plant Molecules—says it too needs advancements. In her interview with Cannabis Science and Technology, Dr. Holmes discusses how she’s using colorimetric analysis to discover novel minor cannabinoids, the potential role of smartphone compatibility in detection, what’s next for cannabinoid research, and more.

How have you used colorimetric analysis to determine cannabinoid concentration and identify different types of cannabinoids? How has this technology advanced the cannabis industry?
Dr. Andrea Holmes: We recently developed the cannabis sensors to broaden the panel of cannabinoids that can be readily identified and quantified. They are still under investigation for precision, reproducibility, and repeatability. So far, we found eight sensors that have a vivid color change in the presence of cannabis flower extracts, concentrates, and topical creams containing THC. While the cannabis sensors are still being developed, they show a lot of potential for both the hemp and marijuana sub-segments of the rapidly growing cannabis industry, both in the United States and internationally. Farmers, hemp and marijuana processors, the U.S. Department of Agriculture (USDA), state agricultural authorities, and law enforcement could use these sensors for testing. The colorimetric arrays were originally developed by me and now are being used successfully to identify and quantify several warfare agents such as nerve gases.

Using colorimetric analysis, what types of cannabinoids have you identified and quantified, and do they have uses in wellness?

Holmes: The sensors have been able to detect accurately THC and CBD. Since the cannabis sativa plant has so many minor cannabinoids—more than 100, including CBG, CBN, CBC, and so on—the sensors can expand to become more specific for all cannabinoids that become of interest. Research shows the major and minor cannabinoids have health and wellness benefits and pharmacological effects for humans and animals. THC has been shown to help with pain, nausea, and neurodegenerative diseases such as multiple sclerosis. CBD is the primary active pharmaceutical ingredient in the U.S. Food and Drug Administration (FDA)-approved drug Epidiolex, which combats certain forms of pediatric epilepsy. CBD is also used widely for its anti-inflammatory, anti-anxiety, and other properties. CBG is great for skin because of its antimicrobial properties, and CBN is helping people improve the quality of their sleep.

What are the next steps using this type of technology?

Holmes: The colorimetric analysis technology needs to be optimized for greater sensitivity and specificity. Farmers and extraction-processing companies will be able to use devices equipped with the colorimetric analysis hardware and software to measure the potency levels of their crops and extracts easily and in real-time. Smartphone compatibility is another important next step. Imagine an app that photographs a cannabinoid and immediately detects identity and quantity.

What hazards or concerns face the extraction industry, and what innovations are you developing to combat these hazards?

Holmes: The extraction-processing industry, no different from most segments of the hemp and marijuana industries, lacks transparency. Most extractors want to keep their intellectual property secret and operate behind closed doors, not allowing anyone to see their facilities. However, the extraction process is not a trade secret but a well-known process with commercially available equipment. Of course, advanced processing companies make equipment modifications and have specific standard operating procedures (SOPs), but generally speaking, it would be hard to discern trade secrets during a facility tour. In contrast, there are companies such as Precision Plant Molecules (PPM) that are fully transparent. It operates on a pharma-grade level and is fully compliant and follows regulations. Companies such as these are changing the perception of the extraction business; they are attracting higher caliber technicians and professionals and experienced scientists holding advanced academic credentials.

What are some of the major challenges associated with the commercial-development process of cannabinoid-containing products?

Holmes: More clinical studies are needed, and sooner rather than later. The industry needs to better substantiate the health and wellness claims being made by consumer products companies that are trying to differentiate and capture market share. Too many quick-buck and bad actors are attracted to the industry’s high growth rate. Shoddy processing, unsafe working conditions, a lack of regulations and enforcement, federal and state confusion regarding the different marijuana and hemp markets, all pose challenges for science-based, compliant, safety-first companies. The explosion of interest, increased societal acceptance, and a number of other factors are driving industry growth, which may in fact be too fast.

What new cannabis products are up and coming (drinkables, pet health) using emerging cannabinoids?

Holmes: Personalized cannabinoid formulations created for consumers’ unique needs. Imagine personalized cannabis extract products with a 5:1:1:1 ratio of CBD to CBN to CBG to CBC that allow the cannabinoids to work together through the “entourage effect”—the synergistic interplay of cannabinoids that has been attributed to the improvement of therapeutic effects.

Can you tell us about other research efforts you have developed, such as the automated image analysis for counting yeast and mold colonies in cannabis?

Holmes: I developed an automated counting method that counts yeast and mold colonies from marijuana flowers at concentrations considered too numerous to count by FDA. Microbiologists usually count colonies manually, which produces a subjective estimate. And obviously, there’s user error, and it’s not reproducible by one user or between users. The new method we developed could serve as an additional or alternative counting tool in state-regulated cannabis testing labs where clients and consumers depend on accurate results before cannabinoid-containing products are sold or consumed. The electronic record of the images and CFU counts provide the clients and laboratories long-term documentation, easy electronic storage, and data review. This is particularly important when a sample fails at >104 CFUs per gram at which point the entire batch of marijuana biomass from where the sample originated would have to be destroyed. Therefore, the electronic evidence of the failed sample is important for the producer of the product, the testing lab, and the consumer.

What’s next in your cannabis research?

Holmes: As noted, I have unfinished business with advancing and commercializing the colorimetric analysis technology into a cost-competitive, easy-to-use, and accurate tool.

At PPM, the R&D effort is transitioning from isolating and purifying the minor cannabinoids with proprietary processing techniques to other important projects such as chemo-profiling. This means we will determine and distinguish reproducible amounts of cannabis plant constituents such as terpenes, flavonoids, cannabinoids, and all the other phytochemicals. The plant is quite amazing—the sheer number of phytocompounds in the plant has been scientifically determined to be more than 700; many of the molecules are labile, and the matrix of material, that is, the plant oil, is complex. Research, science, innovation, and discovery in chemo-profiling will definitely lead the way to improve human and animal health. That is why I got into the industry, and I feel so fortunate to make my contributions.