Tag Archives: terpene

May 9, 2019

The Need for Standardization in Medical Cannabis Testing

By Andrew James

There has been a move towards the legalization of cannabis for medical and/or recreational use across many countries and US states in recent years, leading to greater demand for accurate potency and safety testing. Despite this, there are currently no standardized regulations between states or countries for quality control including content, composition, adulterants, potency or levels of toxic residues. As such, in many cases where regulations are in place, testing is generally carried out at a small number of approved independent testing laboratories.

The need for self-regulation has led to the growth of portable gas chromatography (GC) being used in the field of cannabis testing.This lack of clarity makes it difficult for consumers to make informed decisions about what they are purchasing, an issue which could be damaging to the industry’s changing reputation. As it stands, producers of cannabis and cannabis-derived products can supply goods with potentially harmful contaminants such as fungi or pesticide residues, which are potentially threatening to human health. Most cannabis products sold legally in the US are required to be tested and labelled for THC, the chemical responsible for most of cannabis’s psychoactive effects. A US study found that as few as 20% of recreational cannabis products are accurately labelled with only 17% of products reviewed accurately labelled for THC content (i.e. within 10% of the labeled value). It also found 23% were under labelled, and 60% were over labelled.

If cannabis were to be categorized as a regulated pharmaceutical drug, it would be rigorously tested to comply with stringent rules and regulations regarding quality and safety of the product, as are all other drugs. However, as there is currently no centralized regulatory body that oversees this, the responsibility of quality assurance falls to the grower, manufacturer and sometimes the consumer.

The Need for Cannabis Analysis

The most common requirement when testing cannabis is positive identification and quantification of the total THC:CBD ratio. In a highly competitive marketplace, this information is important, as cannabis consumers tend to equate THC levels with price. In many instances, lower THC products are cheaper and higher THC concentrations make products more expensive. Without robust systems in place for sufficient testing, this information cannot be accurately determined, meaning the customer often cannot make an informed decision.

Pesticide use is surprisingly common in the cannabis cultivation industry

In addition to potency testing, one of the core issues facing the industry and by extension, the end consumer, is the prevalence of pesticides in cannabis products. In the Netherlands, the Ministry of Environment and Health reported that over 90% of cannabis plants tested had pesticides on them. While steps have been taken to tackle this, the lack of cohesion in testing standards combined with the onus on individual labs to carry out testing, has led to some issues within the industry.

Many individual retailers in the U.S. and internationally are self-testing for impurities such as pesticides, heavy metals and microbials. While there is a clear need for standard testing across all locations, the need for self-regulation at present has led to the growth of portable gas chromatography (GC) being used in the field of cannabis testing.

Using GC as an analytical tool

With the increased need for quality control and quality assurance in the largely unregulated cannabis industry, technology is now more accessible to smaller companies and to people with minimal laboratory experience. There are a range of cannabis testing packages available for smaller individual labs which offer more mobile testing with affordable packages. The lower entry price makes GC analysis affordable for more laboratories while still delivering reliable, high quality results.

Portable GC instruments can offer high quality potency testing, pesticide screening, terpene and flavor profiling, and residual solvents analysis. These instruments can give growers and processors an accurate result of cannabinoid percentages, a fundamental piece of information for growers and dispensaries. Systems can be configured for manual injection or a range of autosampler options can be added.

The structure of cannabidiol (CBD), one of 400 active compounds found in cannabis.

GC enables the rapid and accurate identification and quantification of the THC:CBD ratio. This is important for companies which are carrying out self-testing as it allows their customers to have assurances in the short term over the quality of their product, as well as reducing any potential risks to public health.

An example of this in practice is the use of GC by Dutch company Shamanics which carries out testing service for coffee shops in the Netherlands. The company conducts terpene analysis and potency testing to assure the quality of the products it supplies, with a portable GC, which offers the flexibility required without any established guidelines on testing in place.

When testing for potency using the GC, they look for total THC and CBD by converting the acidified versions of the cannabinoids into neutral forms within the heat of the GC injector. The process has flexibility which means that if they need to see both the acidified and neutral versions, they can do this by derivatizing the sample. The accuracy of this process is crucial to Shamanics and similar companies within the industry so that they can accurately judge the quality of a product, and relay this information to retailers and consumers.

The future of GC in standardized testing

While the growing availability of portable GC instruments and the increasing sophistication of individual labs means more companies are able to self-test products, there is still a significant hurdle to overcome in terms of standardising and regulating both the medical and recreational cannabis markets. Where regulation is brought in it should be consistent across states and countries and most importantly, it should be monitored and enforced. In the meantime, responsible producers are using the technology available to them to provide consumers with guarantees that their cannabis products are safe and of a high quality.

January 22, 2019

From The Lab

I Was Wrong… und das ist auch gut so!

By Dr. Markus Roggen

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I was wrong. And that’s a good thing! Based on all available data, I assumed that evaporating ethanol from a cannabis oil/ethanol solution would result in terpene loss. As it turns out, it doesn’t. There are so many beliefs and assumptions about cannabis: Cannabis cures cancer!¹ Smoking cannabis causes cancer!² Sativas help you sleep; Indicas make you creative!^3,4CBD is not psychoactive!⁵ But are these ‘facts’ backed by science? Have they been experimentally tested and validated?

I postulated a theory, designed experiments to validate it and evaluated the results. Simply putting “cannabis backed by science” on your label does not solve the problem. Science is not a marketing term. It’s not even a fixed term. The practice of science is multifaceted and sometimes confusing. It evolved from the traditional model of Inductivism, where observations are used in an iterative process to refine a law/theory that can generalize such observations.⁶ Closely related is Empiricism, which posits that knowledge can only come from observation. Rationalism, on the other hand, believes that certain truths can be directly grasped by one’s intellect.⁷ In the last century, the definition of science was changed from the method by which we study something, such as Inductivism or Rationalism, and refocused on the way we explain phenomena. It states that a theory should be considered scientific if, and only if, it is falsifiable.⁸ All that means is that not the way we study something is what makes it scientific, but the way we explain it.

I wonder how can we use empirical observations and rational deliberations to solve the questions surrounding cannabis? And more importantly, how can we form scientific theories that are falsifiable? Cannabis, the plant, the drug, has long been withheld from society by its legal status. As a result, much of what we know, in fact, the entire industry has thrived in the shadows away from rigorous research. It’s time for this to change. I am particularly concerned by the lack of fundamental research in the field. I am not even talking about large questions, like the potential medical benefit of the plant and its constituents. Those are for later. I’m talking about fundamental, mundane questions like how many lumens per square centimetre does the plant need for optimal THC production? What are the kinetics of cannabis extraction in different solvents? What are the thermodynamics of decarboxylation? Where do major cannabinoids differ or align in terms of water solubility and viscosity?

The lack of knowledge and data in the cannabis field puts us in the precarious position of potentially chasing the wrong goals, not to mention wasting enormous amounts of time and money. Here’s a recent example drawn from personal experience:Certainly, I cannot be the only one who has made an incorrect assumption based on anecdotes and incomplete data?

Some of the most common steps in cannabis oil production involve ethanol solutions. Ethanol is commonly removed from extraction material under reduced pressure and elevated heat in a rotary evaporator. I expected that this process would endanger the terpenes in the oil – a key component of product quality. My theory was that volatile terpenes⁹ would be lost in the rotary evaporator during ethanol¹⁰ removal. The close values of vapor pressure for terpenes and ethanol make this a reasonably assumed possibility.¹¹ In the summer of 2018, I finally got the chance to test it. I designed experiments at different temperatures and pressures, neat and in solution, to quantify the terpene lost in ethanol evaporation. I also considered real life conditions and limitations of cannabis oil manufacturers. After all the experiments were done, the results unequivocally showed that terpenes do not evaporate in a rotary evaporator when ethanol is removed from cannabis extracts.¹² As it turns out, I was wrong.

We, as an industry, need to start putting money and effort into fundamental cannabis research programs. But, at least I ran the experiments! I postulated a theory, designed experiments to validate it and evaluated the results. At this point, and only this point, can I conclude anything about my hypothesis, even if that is that my working theory needs to be revised. Certainly, I cannot be the only one who has made an incorrect assumption based on anecdotes and incomplete data?

There is a particular danger when using incomplete data to form conclusions. There are many striking examples in the medical literature and even the casual observer might know them. The case of hormone replacement therapy for menopause and the associated risks of cardiovascular diseases showed how observational studies and well-designed clinical trials can lead to contradicting results.¹³ In the thirties of the last century, lobotomy became a cure-all technique for mental health issues.¹⁴ Dr. Moniz even won the Nobel Prize in Medicine for it.¹⁵ And it must come as no surprise when WIRED states “that one generation’s Nobel Prize-winning cure is another generation’s worst nightmare.”¹⁶ And with today’s knowledge is impossible to consider mercury as a treatment for syphilis, but that is exactly what it was used as for many centuries.¹⁷ All those examples, but the last one in particular should “be a good example of the weight of tradition or habit in the medical practice, […] of the necessity and the difficulties to evaluate the treatments without error.”¹⁸ There is the danger that we as cannabis professionals fall into the same trap and believe the old stories and become dogmatic about cannabis’ potential.

We, as an industry, need to start putting money and effort into fundamental cannabis research programs. That might be by sponsoring academic research,¹⁹ building in-house research divisions,²⁰ or even building research networks.²¹ I fully believe in the need for fundamental cannabis research, even the non-sexy aspects.²² Therefore, I set up just that: an independent research laboratory, focused on fundamental cannabis research where we can test our assumptions and validate our theories. Although, I alone cannot do it all. I likely will be wrong somewhere (again). So, please join me in this effort. Let’s make sure cannabis science progresses.

References

No, it does not. There are preliminary in-situ studies that point at anti-cancer effects, but its more complicated. The therapeutic effects of Cannabis and cannabinoids: An update from the National Academies of Sciences, Engineering and Medicine report, Abrams, Donald I., European Journal of Internal Medicine, Volume 49, 7 – 11
No, it does not. National Academies of Sciences, Engineering, and Medicine. 2017. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. Washington, DC: The National Academies Press. https://doi.org/10.17226/24625.
No, it does not. The chemical profile of the plant dictates the biological effects on humans, not the shape of the leaf. Justin T. Fischedick, Cannabis and Cannabinoid Research, Volume: 2 Issue 1: March 1, 2017
Indica and Sativa are outdated terms. Piomelli D, Russo EB. The Cannabis sativa versus Cannabis indica debate: An Interview with Ethan Russo, MD. Cannabis Cannabinoid Res 2016; 1: 44–46.
No, it is. CBD’s supposed “calming effects” is indeed a psychoactive effect. However, it is not intoxicating like THC. Russo E.B., Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects.Br. J. Pharmacol. 2011; 163: 1344-1364
As attributed to Francis Bacon.
See the work by philosopher Baruch Spinoza.
As theorized by Karl Popper.
Monoterpenes have a vapor pressure in the low to mid hundreds of Pascals at room temperature.
Vapor pressure of 5.95 kPa at 20˚C.
Furthermore, there is always the possibility of azeotropes in complex mixtures. Azeotropes are mixtures of two or more liquids that have different boiling points individually, but in mixture boil together.
Terpene Retention via Rotary Evaporator Application Note, Heidolph North America
https://www.pharmaceutical-journal.com/research/review-article/establishing-the-risk-related-to-hormone-replacement-therapy-and-cardiovascular-disease-in-women/20202066.article?firstPass=false
https://psychcentral.com/blog/the-surprising-history-of-the-lobotomy/
https://en.wikipedia.org/wiki/António_Egas_Moniz
https://www.wired.com/2011/03/lobotomy-history/
https://www.infezmed.it/media/journal/Vol_21_4_2013_10.pdf
https://www.ncbi.nlm.nih.gov/pubmed/11625051
Canopy Growth funds a professorship of cannabis science at UBC. Tilray collaborates with UCSD on a phase I/II clinical trial.
For examples see: NIBR, PMISCIENCE.
For examples see: CEMI, theAIRnet, Future Sky.
Research that does not lead to short-term stock value spikes but long-term progress

August 1, 2018

Orange Photonics Introduces Terpenes+ Module in Portable Analyzer

By Aaron G. Biros

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Last week at the National Cannabis Industry Association’s (NCIA) Cannabis Business Summit, Orange Photonics unveiled their newest product added to their suite of testing instruments for quality assurance in the field. The Terpenes+ Module for the LightLab Cannabis Analyzer, which semi-quantitatively measures terpenes, Cannabichromene (CBC) and degraded THC, adds three new chemical analyses to the six cannabinoids it already reports.

CBC, a cannabinoid typically seen in hemp and CBD-rich plants, has been linked to some potentially impactful medical applications, much like the findings regarding the benefits of CBD. The module that tests for it, along with terpenes and degraded THC, can be added to the LightLab without any changes to hardware or sample preparation.

According to Dylan Wilks, chief technology officer of Orange Photonics, this could be a particularly useful tool for distillate producers looking for extra quality controls. Cannabis distillates are some of the most prized cannabis products around, but the heat used to create them can also create undesirable compounds,” says Wilks. “Distillate producers can see potency drop more than 25% if their process isn’t optimized”. With this new Terpenes+ Module, a distillate producer could quantify degraded THC content and get an accurate reading for their QC/QA department.

We spoke with Stephanie McArdle, president of Orange Photonics, to learn more about their instruments designed for quality assurance for growers and extractors alike.

According to McArdle, this could help cultivators and processors understand and value their product when terpene-rich products are the end goal. “Rather than try to duplicate the laboratory analysis, which would require expensive equipment and difficult sample preparation, we took a different approach. We report all terpenes as a single total terpene number,” says McArdle. “The analyzer only looks for monoterpenes (some common monoterpenes are myrcene, limonene and alpha-pinene), and not sesquiterpenes (the other major group of cannabis terpenes, such as Beta- Caryophyllene and Humulene) so the analysis is semi-quantitative. What we do is measure the monoterpenes and make an assumption that the sesquiterpenes are similar to an average cannabis plant to calculate a total terpene content.” She says because roughly 80% of terpenes found in cannabis are monoterpenes, this should produce accurate results, though some exotic strains may not result in accurate terpene content using this method.

As growers look to make their product unique in a highly competitive market, many are looking at terpenes as a source of differentiation. There are a variety of areas where growers can target higher terpene production, McArdle says. “During production, a grower may want to select plants for growing based on terpene content, or adjust nutrient levels, lighting, etc. to maximize terpenes,” says McArdle. “During the curing process, adjusting the environmental conditions to maximize terpene content is highly desirable.” Terpenes are also beginning to get recognized for their potential medical and therapeutic values as well, notably as an essential piece in the Entourage Effect. “Ultimately, it comes down to economics – terpene rich products have a higher market value,” says McArdle. “If you’re the grower, you want to prove that your product is superior. If you’re the buyer, you want to ensure the product you buy is high quality before processing it into other products. In both cases, knowing the terpene content is critical to ensuring you’re maximizing profits.”

Orange Photonics’ LightLab operates very similarly to instruments you might find in a cannabis laboratory. Many cannabis testing labs use High Performance Liquid Chromatography (HPLC) to analyze hemp or cannabis samples. “The primary difference between LightLab and an HPLC is that we operate at lower pressures and rely on spectroscopy more heavily than a typical HPLC analysis does,” says McArdle. “Like an HPLC, LightLab pushes an extracted cannabis sample through a column. The column separates the cannabinoids in the sample by slowing down cannabinoids by different amounts based on their affinity to the column.” McArdle says this is what allows each cannabinoid to exit the column at a different time. “For example, CBD may exit the column first, then D9THC and so on,” says McArdle. “Once the column separates the cannabinoids, they are quantified using optical spectroscopy- basically we are using light to do the final quantification.”

June 11, 2018

The Four Pillars of Cannabis Processing

By Christian Sweeney

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Cannabis extraction has been used as a broad term for what can best be described as cannabis processing. A well-thought-out cannabis process goes far beyond just extraction, largely overlapping with cultivation on the front-end and product development on the back-end¹. With this in mind, four pillars emerge as crucial capabilities for developing a cannabis process: Cultivation, Extraction, Analytics and Biochemistry.

The purpose and value of each pillar on their own is clear, but it is only when combined that each pillar can be optimized to provide their full capacities in a well-designed process. As such, it is best to define the goals of each pillar alone, and then explain how they synergize with each other.

At the intersection of each pillar, specific technology platforms exist that can effectively drive an innovation and discovery cycle towards the development of ideal products.Cultivation is the foundation of any horticultural process, including cannabis production. Whether the goal be to convert pigments, flavors or bioactive compounds into a usable form, a natural process should only utilize what is provided by the raw material, in this case cannabis flower. That means cultivation offers a molecular feedstock for our process, and depending on our end goals there are many requirements we may consider. These requirements start as simply as mass yield. Various metrics that can be used here include mass yield per square foot or per light. Taken further, this yield may be expressed based not only on mass, but the cannabinoid content of the plants grown. This could give rise to a metric like CBD or THC yield per square foot and may be more representative of a successful grow. Furthermore, as scientists work to learn more about how individual cannabinoids and their combinations interact with the human body, cultivators will prioritize identifying cultivars that provide unique ratios of cannabinoids and other bioactive compounds consistently. Research into the synergistic effect of terpenes with cannabinoids suggests that terpene content should be another goal of cultivation². Finally, and most importantly, it is crucial that cultivation provide clean and safe materials downstream. This means cannabis flower free of pesticides, microbial growth, heavy metals and other contaminants.

Extraction is best described as the conversion of target molecules in cannabis raw material to a usable form. Which molecules those are depends on the goals of your product. This ranges from an extract containing only a pure, isolated cannabinoid like CBD, to an extract containing more than 100 cannabinoids and terpenes in a predictable ratio. There are countless approaches to take in terms of equipment and process optimization in this space so it is paramount to identify which is the best fit for the end-product¹. While each extraction process has unique pros and cons, the tunability of supercritical carbon dioxide provides a flexibility in extraction capabilities unlike any other method. This allows the operator to use a single extractor to create extracts that meet the needs of various product applications.

Analytics provide a feedback loop at every stage of cannabis production. Analytics may include gas chromatography methods for terpene content³ or liquid chromatography methods for cannabinoids^{3, 4, 5}. Analytical methods should be specific, precise and accurate. In an ideal world, they can identify the compounds and their concentrations in a cannabis product. Analytics are a pillar of their own due simply to the efforts required to ensure the quality and reliability of results provided as well as ongoing optimization of methods to provide more sensitive and useful results. That said, analytics are only truly harnessed when paired with the other three pillars.

Biochemistry can be split into two primary focuses. Plant biochemistry focuses back towards cultivation and enables a cannabis scientist to understand the complicated pathways that give rise to unique ratios of bioactive molecules in the plant. Human biochemistry centers on how those bioactive molecules interact with the human endocannabinoid system, as well as how different routes of administration may affect the pharmacokinetic delivery of those active molecules.

Each of the pillars require technical expertise and resources to build, but once established they can be a source of constant innovation. Fig. 1 above shows how each of these pillars are connected. At the intersection of each pillar, specific technology platforms exist that can effectively drive an innovation and discovery cycle towards the development of ideal products.

For example, at the intersection of analytics and cultivation I can develop raw material specifications. This sorely needed quality measure could ensure consistencies in things like cannabinoid content and terpene profiles, more critically they can ensure that the raw material to be processed is free of contamination. Additionally, analytics can provide feedback as I adjust variables in my extraction process resulting in optimized methods. Without analytics I am forced to use very rudimentary methods, such as mass yield, to monitor my process. Mass alone tells me how much crude oil is extracted, but says nothing about the purity or efficiency of my extraction process. By applying plant biochemistry to my cultivation through the use of analytics I could start hunting for specific phenotypes within cultivars that provide elevated levels of specific cannabinoids like CBC or THCV. Taken further, technologies like tissue culturing could rapidly iterate this hunting process⁶. Certainly, one of the most compelling aspects of cannabinoid therapeutics is the ability to harness the unique polypharmacology of various cannabis cultivars where multiple bioactive compounds are acting on multiple targets⁷. To eschew the more traditional “silver bullet” pharmaceutical approach a firm understanding of both human and plant biochemistry tied directly to well characterized and consistently processed extracts is required. When all of these pillars are joined effectively we can fully characterize our unique cannabis raw material with targeted cannabinoid and terpene ratios, optimize an extraction process to ensure no loss of desirable bioactive compounds, compare our extracted product back to its source and ensure we are delivering a safe, consistent, “nature identical” extract to use in products with predictable efficacies.

Using these tools, we can confidently set about the task of processing safe, reliable and well characterized cannabis extracts for the development of world class products.

[1] Sweeney, C. “Goal-Oriented Extraction Processes.” Cannabis Science and Technology, vol 1, 2018, pp 54-57.

[2] Russo, E. B. “Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects.” British Journal of Pharmacology, vol. 163, no. 7, 2011, pp. 1344–1364.

[3] Giese, Matthew W., et al. “Method for the Analysis of Cannabinoids and Terpenes in Cannabis.” Journal of AOAC International, vol. 98, no. 6, 2015, pp. 1503–1522.

[4] Gul W., et al. “Determination of 11 Cannabinoids in Biomass and Extracts of Different Varieties of Cannabis Using high-Performance Liquid Chromatography.” Journal of AOAC International, vol. 98, 2015, pp. 1523-1528.

[5] Mudge, E. M., et al. “Leaner and Greener Analysis of Cannabinoids.” Analytical and Bioanalytical Chemistry, vol. 409, 2017, pp. 3153-3163.

[6] Biros, A. G., Jones, H. “Applications for Tissue Culture in Cannabis Growing: Part 1.” Cannabis Industry Journal, 13 Apr. 2017, www.cannabisindustryjournal.com/feature_article/applications-for-tissue-culture-in-cannabis-growing-part-1/.

[7] Brodie, James S., et al. “Polypharmacology Shakes Hands with Complex Aetiopathology.” Trends in Pharmacological Sciences, vol. 36, no. 12, 2015, pp. 802–821.

May 9, 2018

Refining Techniques for Growing Cannabis

By Cannabis Industry Journal Staff

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As the cannabis industry in the United States and throughout the world develops, the market is getting more competitive. Markets in a number of states are experiencing disruptions that will have lasting effects for cultivators, including oversupply and supply chain bottlenecks. Now more than ever, growers need to look for ways to differentiate their product or gain a bigger market share. Looking at yield efficiency, quality improvements and analyzing the cost of inputs versus value of the crop can help growers make the right choices in technology for lighting, irrigation and pest control among other technologies.

adamplants — Adam Jacques, co-founder of Growers’ Guild Gardens and Sproutly

A series of free webinars in two weeks can help growers learn about some of the more advanced techniques in improving yield and quality. The Cannabis Cultivation Virtual Conference on May 23^rdwill explore a variety of tips and tricks for taking their cultivation operation to the next level. This event is free to attendees, made possible by sponsors VividGro and CannaGrow Expo.

Attendees will hear from experts in cannabis cultivation on a range of topics, including breeding, drying, curing, environmental monitoring and micropropagation. Adam Jacques, co-founder of Growers’ Guild Gardens and Sproutly, will discuss some of his experience with breeding high-CBD strains in Oregon. His talk will delve into some of the proper breeding procedures, along with how to hunt for particular phenotypes and developing specific cannabinoids and terpenes.

Dr. Allison Justice, vice president of cultivation at Outco, is going to present some of her findings in drying and curing at the company. She plans on sharing her research on how the post-harvest stages can affect and control the chemical makeup of flower. She’ll also discuss some new protocols to monitor the dry and cure of cannabis flowers so we are able to modulate the terpene and cannabinoid profiles.

More information on the other speakers at this event and how to register for free can be found here.

April 18, 2018

From The Lab

The Other Side of Cannabis: Terpenes

By Dr. Zacariah Hildenbrand, Allegra Leghissa, Dr. Kevin A. Schug

2 Comments

Have you ever wondered why all beers have that strong, characteristic smell? Or why you could tell the smell of cannabis apart from any other plant? The answer is simple – terpenes.

These 55,000 different molecules are responsible for a majority of the odors and fragrances around us, from a pine forest, to the air diffuser in your house ^1–3. They all share the same precursor, isoprene, and because of that, they are all related and have similar molecular structures. Unfortunately, it is this uncanny similarity that makes their analysis so challenging; we still lack a complete list of which terpenes expected to be found in each given plant species ^1,2.

Many different methods have been developed in an effort to provide a time-optimized and straightforward analysis. Gas chromatography (GC) is usually center stage due to the volatility of the terpenes. Therefore, there is significant concern with the type of GC detector used ².

The flame ionization detector (FID) is a good quantitative detector for GC, but qualitatively it does not provide any information, except for retention time; the differentiation between terpene species is achieved solely by use of retention indices (RI), which are based on elution times from a particular GC stationary phase. The best part of the FID is its low cost, reliability, and relatively easy interface, which make it an effective tool for quality control (QC) but less so with respect to research and discovery ².

The primary choice for a research setting is the mass spectrometer (MS) detector. It is more expensive and complicated than FID, but importantly, it provides both good quantitative capabilities, and it provides mass spectra for each species that elutes from the chromatograph. However, for terpene analysis, it may still not be the best detector choice. Since terpene class molecules share many structural and functional similarities, even their fragmentation and sub-sequential identification by MS may lead to inconsistent results, which need to be confirmed by use of RI. Still, MS is a better qualitative analysis tool than the FID, especially for distinguishing non-isobaric terpenes ².

Recently, new technology based on vacuum ultraviolet spectroscopy (VUV) has been developed as a new GC detector. The VUV detector enables analysis of virtually all molecules; virtually all chemical compounds absorb light in the range in the 125-240 nm wavelength range probed by the detector, making it an essentially universal detector ^4–11. Previously, spectroscopic absorption detectors for GC have lacked sufficient energy to measure absorption of most GC-amenable species. The VUV detector fills a niche, which is complementary to MS detection in terms of the qualitative information it provides.

With the VUV detector, each compound exhibits its own unique absorbance spectrum. Even isomers and isobars, which are prevalent in terpene mixtures and can be difficult to distinguish different species by their electron ionization mass spectra, can be well differentiated based on their VUV spectra ^6,9,10. Nevertheless, because analytes exhibit different spectra, it is not required to achieve a perfect chromatographic separation of the mixture components. Co-eluting peaks can be separated post-run through the use of library spectra and software inherent to the instrument ^4,10. This ability is called “deconvolution”, and it is based on the fact that two co-eluting terpenes will give a peak with an absorbance spectrum equal to the sum of the two single absorbance spectra ⁴. Figure 1 shows the deconvolution process for two co-eluting terpenes, camphor and (-)-isopulegol. Due to their different absorbance spectra (Figure 1C), it is possible to fully separate the two peaks in post-run, obtaining sharp peaks for both analytes ⁶.

The deconvolution process has been shown to yield precise and accurate results. Thus, chromatographic resolution can be sacrificed in favor of spectroscopic resolution; this enables the development of methods with faster run times. With the ability to deconvolve unresolved peaks, a long temperature ramp to chromatographically separate all isomeric terpenes is not required ⁶. Additionally, the presence of coeluting components, which might normally go undetected with some GC detectors, can be easily judged based on comparison of the measured spectra with pure reference spectra contained in the VUV spectral library.

The other issue in terpenes analysis is the extraction process. Terpenes can be extracted with the use of solvents (e.g., methanol, ethanol, hexane, and cyclohexane, among others), but the process is usually time-consuming, costly and not so environmentally-friendly ². The plant needs to be manually crushed and then aliquots of solvent are used to extract components from the plant, ideally at least 3 times and combined to achieve acceptable results. The problem is that some terpenes may respond better to a certain solvent, making their extraction easier and more optimized than for others ². The choice of solvent can cause discrimination against the extraction some terpenes, which limits the comprehensiveness of analysis.

Headspace is another technique that can be used for the sample preparation of terpenes. Headspace sampling is based on heating the solid or liquid sample inside a sealed vial, and then analyzing the air above it after sufficient equilibration. In this way, only volatile analytes are extracted from the solid/liquid sample into the gas phase; this allows relatively interference-free sampling ^12–14.

How do we know whether our extraction analysis methods are correct and comprehensive for a certain plant sample? Unfortunately, there is not a complete list of available molecules for each plant species, and even if two specimens may smell really similar to our nose, their terpenes profiles may be notably different. When working with a new plant material, it is difficult to predict the extraction efficiency for the vast array of terpenes that may be present. We can only perform it with different extraction and detection methods, and compare the results.

The route for a comprehensive and fast analysis of terpenes is therefore still long; however, their intoxicating aromas and inherent medicinal value has provided a growing impetus for researchers around the world. Considering the evolving importance of Cannabis and the growing body of evidence on the synergistic effects between terpenes and cannabinoids, it is likely that newly improved extraction and analysis methods will be developed, paving the way for a more complete list of terpene species that can be found in different cultivars. The use of new analytical technologies, such as the VUV detector for GC, should aid considerably in this endeavor.

References:

[1] Breitmaier E., Terpenes: Flavors, Fragrances, Pharmaca, Pheromones. John Wiley & Sons 2006.

[2] Leghissa A., Hildenbrand Z. L., Schug K. A., A Review of Methods for the Chemical Characterization of Cannabis Natural Products. J. Sep. Sci.2018, 41, 398–415 .

[3] Benvenuto E., Misra B. B., Stehle F., Andre C. M., Hausman J.-F., Guerriero G., Cannabis sativa: The Plant of the Thousand and One Molecules. Front. Plant Sci2016, 719, DOI: 10.3389/fpls.2016.00019.

[4] Schug K. A., Sawicki I., Carlton D. D., Fan H.,Mcnair H. M.,Nimmo J. P., Kroll P.,Smuts J.,Walsh P., Harrison D., Vacuum Ultraviolet Detector for Gas Chromatography. Anal. Chem.2014, 86, 8329–8335 .

[5] Fan H.,Smuts J., Walsh P.,Harrison D., Schug K. A., Gas chromatography-vacuum ultraviolet spectroscopy for multiclass pesticide identification. J. Chromatogr. A2015, DOI: 10.1016/j.chroma.2015.02.035.

[6] Qiu C.,Smuts J., Schug K. A., Analysis of terpenes and turpentines using gas chromatography with vacuum ultraviolet detection. J. Sep. Sci.2017, 40, 869–877 .

[7] Leghissa A., Smuts J., Qiu C., Hildenbrand Z. L., Schug K. A., Detection of cannabinoids and cannabinoid metabolites using gas chromatography-vacuum ultraviolet spectroscopy. Sep. Sci. Plus2018, 1.

[8] Bai L.,Smuts J., Walsh P., Fan H., Hildenbrand Z., Wong D., Wetz D., Schug K. A., Permanent gas analysis using gas chromatography with vacuum ultraviolet detection. J. Chromatogr. A2015,1388, 244–250 .

[9] Skultety L., Frycak P., Qiu C.,Smuts J., Shear-Laude L., Lemr K., Mao J. X., Kroll P., Schug K. A., Szewczak A., Vaught C., Lurie I., Havlicek V., Resolution of isomeric new designer stimulants using gas chromatography – Vacuum ultraviolet spectroscopy and theoretical computations. Anal. Chim. Acta2017, 971, 55–67 .

[10] Bai L., Smuts J., Walsh P., Qiu C., McNair H. M., Schug K. ., Pseudo-absolute quantitative analysis using gas chromatography–vacuum ultraviolet spectroscopy–a tutorial. Anal. Chim. Acta2017, 953, 10–22 .

[11] Schenk J., Nagy G., Pohl N. L. B., Leghissa A., Smuts J., Schug K. A., Identification and deconvolution of carbohydrates with gas chromatography-vacuum ultraviolet spectroscopy. J. Chromatogr. A2017, 1513, 210–221 .

[12] Van Opstaele F., De Causmaecker B., Aerts G., De Cooman L., Characterization of novel varietal floral hop aromas by headspace solid phase microextraction and gas chromatography-mass spectrometry/olfactometry. J. Agric. Food Chem.2012, 60, 12270−12281 .

[13] Hamm S., Bleton J., Connan J., Tchapla A., A chemical investigation by headspace SPME and GC-MS of volatile and semi-volatile terpenes in various olibanum samples. Phytochemistry2005,66, 1499–1514 .

[14] Aberl A., Coelhan M., Determination of volatile compounds in different hop Varieties by headspace-trap GC/MS-in comparison with conventional hop essential oil analysis. J. Agric. Food Chem.2012, 60, 2785−2792 .

March 7, 2018

Turning the Oregon Outdoor Market into a Research Opportunity

By Dr. Zacariah Hildenbrand, Dr. Kevin A. Schug

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Much has been made about the plummeting market value of cannabis grown outdoors in Oregon. This certainly isn’t a reflection of the product quality within the marketplace, but more closely attributable to the oversaturation of producers in this space. This phenomenon has similarities to that of ‘Tulip Mania’ within the Dutch Golden Age, whereby tulip bulbs were highly coveted assets one day, and almost worthless the next. During times like these, it is very easy for industry professionals to become disheartened; however, from a scientific perspective, this current era in Oregon represents a tremendous opportunity for discovery and fundamental research.

Dr. Zacariah Hildenbrand, chief technical officer at Inform Environmental.

As we have mentioned in previous presentations and commentaries, our research group is interested in exploring the breadth of chemical constituents expressed in cannabis to discover novel molecules, to ultimately develop targeted therapies for a wide range of illnesses. Intrinsically, this research has significant societal implications, in addition to the potential financial benefits that can result from scientific discovery and the development of intellectual property. While conducting our experiments out of Arlington, Texas, where the study of cannabis is highly restricted, we have resorted to the closet genetic relative of cannabis, hops (Humulus lupulus), as a surrogate model of many of our experiments (Leghissa et al., 2018a). In doing so, we have developed a number of unique methods for the characterization of various cannabinoids and their metabolites (Leghissa et al., 2018b; Leghissa et al., 2018c). These experiments have been interesting and insightful; however, they pale in comparison to the research that could be done if we had unimpeded access to diverse strains of cannabis, as are present in Oregon. For example, gas chromatography-vacuum ultraviolet spectroscopy (GC-VUV) is a relatively new tool that has recently been proven to be an analytical powerhouse for the differentiation of various classes of terpene molecules (Qiu et al., 2017). In Arlington, TX, we have three such GC-VUV instruments at our disposal, more than any other research institution in the world, but we do not have access to appropriate samples for application of this technology. Similarly, on-line supercritical fluid extraction – supercritical fluid chromatography – mass spectrometry (SFE-SFC-MS) is another capability currently almost unique to our research group. Such an instrument exhibits extreme sensitivity, supports in situ extraction and analysis, and has a wide application range for potential determination of terpenes, cannabinoids, pesticides and other chemical compounds of interest on a single analytical platform. Efforts are needed to explore the power and use of this technology, but they are impeded based on current regulations.

Dr Kevin Schug — Dr. Kevin A. Schug, Professor and the Shimadzu Distinguished Professor of Analytical Chemistry in the Department of Chemistry and Biochemistry at The University of Texas at Arlington (UTA)

Circling back, let’s consider the opportunities that lie within the abundance of available outdoor-grown cannabis in Oregon. Cannabis is extremely responsive to environmental conditions (i.e., lighting, water quality, nutrients, exposure to pest, etc.) with respect to cannabinoid and terpene expression. As such, outdoor-grown cannabis, despite the reduced market value, is incredibly unique from indoor-grown cannabis in terms of the spectrum of light to which it is exposed. Indoor lighting technologies have come a long way; full-spectrum LED systems can closely emulate the spectral distribution of photon usage in plants, also known as the McCree curve. Nonetheless, this is emulation and nothing is ever quite like the real thing (i.e., the Sun). This is to say that indoor lighting can certainly produce highly potent cannabis, which exhibits an incredibly robust cannabinoid/terpene profile; however, one also has to imagine that such lighting technologies are still missing numerous spectral wavelengths that, in a nascent field of study, could be triggering the expression of unknown molecules with unknown physiological functions in the human body. Herein lies the opportunity. If we can tap into the inherently collaborative nature of the cannabis industry, we can start analyzing unique plants, having been grown in unique environments, using unique instruments in a facilitative setting, to ultimately discover the medicine of the future. Who is with us?

References

Leghissa A, Hildenbrand ZL, Foss FW, Schug KA. Determination of cannabinoids from a surrogate hops matrix using multiple reaction monitoring gas chromatography with triple quadrupole mass spectrometry. J Sep Sci 2018a; 41: 459-468.

Leghissa A, Hildenbrand ZL, Schug KA. Determination of the metabolites of Δ9-Tetrahydrocannabinol using multiple reaction monitoring gas chromatography – triple quadrapole – mass spectrometry. Separation Science Plus 2018b; 1: 43-47.

Leghissa A, Smuts J, Changling Q, Hildenbrand ZL, Schug KA. Detection of cannabinoids and cannabinoid metabolites using gas chromatography-vacuum ultraviolet spectroscopy. Separation Science Plus 2018c; 1: 37-42.

Qiu C, Smuts J, Schug KA. Analysis of terpenes and turpentines using gas chromatography with vacuum ultraviolet detection. J Sep Sci 2017; 40: 869-877.

February 7, 2018

Managing Cannabis Testing Lab Workflows using LIMS

By Dr. Susan Audino

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With the state led legalization of both adult recreational and medical cannabis, there is a need for comprehensive and reliable analytical testing to ensure consumer safety and drug potency. Cannabis-testing laboratories receive high volumes of test requests from cannabis cultivators for testing quantitative and qualitative aspects of the plant. The testing market is growing as more states bring in stricter enforcement policies on testing. As the number of testing labs grow, it is anticipated that the laboratories that are now servicing other markets, including high throughput contract labs, will cross into cannabis testing as regulations free up. As the volume of tests each lab performs increases, the need for laboratories to make effective use of time and resource management, such as ensuring accurate and quick results, reports, regulatory compliance, quality assurance and many other aspects of data management becomes vital in staying competitive.

Cannabis Testing Workflows

To be commercially competitive, testing labs offer a comprehensive range of testing services. These services are available for both the medical and recreational cannabis markets, including:

Detection and quantification of both acid and neutral forms of cannabinoids
Screening for pesticide levels
Monitoring water activity to indicate the possibility of microbiological contamination
Moisture content measurements
Terpene profiling
Residual solvents and heavy metal testing
Fungi, molds, mycotoxin testing and many more

Although the testing workflows differ for each test, here is a basic overview of the operations carried out in a cannabis-testing lab:

Cannabis samples are received.
The samples are processed using techniques such as grinding and homogenization. This may be followed by extraction, filtration and evaporation.
A few samples will be isolated and concentrated by dissolving in solvents, while others may be derivatized using HPLC or GC reagents
The processed samples are then subjected to chromatographic separation using techniques such as HPLC, UHPLC, GC and GC-MS.
The separated components are then analyzed and identified for qualitative and quantitative analysis based on specialized standards and certified reference materials.
The quantified analytical data will be exported from the instruments and compiled with the corresponding sample data.
The test results are organized and reviewed by the lab personnel.
The finalized test results are reported in a compliant format and released to the client.

In order to ensure that cannabis testing laboratories function reliably, they are obliged to follow and execute certain organizational and regulatory protocols throughout the testing process. These involve critical factors that determine the accuracy of testing services of a laboratory.

Factors Critical to a Cannabis Testing Laboratory

Accreditations & Regulatory Compliance: Cannabis testing laboratories are subject to regulatory compliance requirements, accreditation standards, laboratory practices and policies at the state level. A standard that most cannabis testing labs comply to is ISO 17025, which sets the requirements of quality standards in testing laboratories. Accreditation to this standard represents the determination of competence by an independent third party referred to as the “Accreditation Body”. Accreditation ensures that laboratories are adhering to their methods. These testing facilities have mandatory participation in proficiency tests regularly in order to maintain accreditation.
Quality Assurance, Standards & Proficiency Testing: Quality assurance is in part achieved by implementing standard test methods that have been thoroughly validated. When standard methods are not available, the laboratory must validate their own methods. In addition to using valid and appropriate methods, accredited laboratories are also required to participate in appropriate and commercially available Proficiency Test Program or Inter-Laboratory Comparison Study. Both PT and ILC Programs provide laboratories with some measure of their analytic performance and compare that performance with other participating laboratories.
CloudLIMS Cannabis Testing LIMS: Multi-analyte Configuration for Cannabis Testing Services
Real-time Collaboration: Testing facilities generate metadata such as data derived from cannabis samples and infused products. The testing status and test results are best served for compliance and accessibility when integrated and stored on a centralized platform. This helps in timely data sharing and facilitates informed decision making, effective cooperation and relationships between cannabis testing facilities and growers. This platform is imperative for laboratories that have grown to high volume throughput where opportunities for errors exist. By matching test results to samples, this platform ensures consistent sample tracking and traceability. Finally, the platform is designed to provide immediate, real-time reporting to individual state or other regulatory bodies.
Personnel Management: Skilled scientific staff in cannabis-testing laboratories are required to oversee testing activities. Staff should have experience in analytical chromatography instruments such as HPLC and GC-MS. Since samples are often used for multi-analytes such as terpenes, cannabinoids, pesticides etc., the process often involves transferring samples and tests from one person to another within the testing facility. A chain of custody (CoC) is required to ensure traceability and ‘ownership’ for each person involved in the workflow.

LIMS for Laboratory Automation

Gathering, organizing and controlling laboratory-testing data can be time-consuming, labor-intensive and challenging for cannabis testing laboratories. Using spreadsheets and paper methods for this purpose is error-prone, makes data retrieval difficult and does not allow laboratories to easily adhere to regulatory guidelines. Manual systems are cumbersome, costly and lack efficiency. One way to meet this challenge is to switch to automated solutions that eliminate many of the mundane tasks that utilize valuable human resources.^. Laboratory automation transforms the data management processes and as a result, improves the quality of services and provides faster turnaround time with significant cost savings. Automating the data management protocol will improve the quality of accountability, improve technical efficiency, and improve fiscal resources.

Real Time Test Status in CloudLIMS

A Laboratory Information Management System (LIMS) is a software tool for testing labs that aids efficient data management. A LIMS organizes, manages and communicates all laboratory test data and related information, such as sample and associated metadata, tests, Standard Operating Procedures (SOPs), test reports, and invoices. It also enables fully automated data exchange between instruments such as HPLCs, GC-FIDs, etc. to one consolidated location, thereby reducing transcription errors.

How LIMS Helps Cannabis Testing Labs

LIMS are much more capable than spreadsheets and paper-based tools for streamlining the analytical and operational lab activities and enhances the productivity and quality by eliminating manual data entry. Cloud-enabled LIMS systems such as CloudLIMS are often low in the total cost of acquisition, do not require IT staff and are scalable to help meet the ever changing business and regulatory compliance needs. Some of the key benefits of LIMS for automating a cannabis-testing laboratory are illustrated below [Table 1]:

Key Functionality	Benefit
Barcode label designing and printing	Enables proper labelling of samples and inventory Follows GLP guidelines
Instant data capture by scanning barcodes	Facilitates quick client registration and sample access
360⁰ data traceability	Saves time and resources for locating samples and other records
Inventory and order management	Supports proactive planning/budgeting and real time accuracy
Custodian management	Promotes overall laboratory organization by assigning custodians for samples and tests Maintains the Chain-of-custody (CoC)
Test management	Accommodates pre-loaded test protocols to quickly assign tests for incoming samples
Accounting for sample and inventory quantity	Automatically deducts sample and inventory quantities when consumed in tests
Package & shipment management	Manages incoming samples and samples that have been subcontracted to other laboratories
Electronic data import	Electronically imports test results and metadata from integrated instruments Eliminates manual typographical errors
Report management	Generates accurate, customizable, meaningful and test reports for clients Allows user to include signatures and additional sections for professional use
21 CFR Part 11 compliant	Authenticates laboratory activities with electronic signatures
ISO 17025 accreditation	Provides traceable documentary evidence required to achieve ISO 17025 accreditation
Audit trail capabilities	Adheres to regulatory standards by recording comprehensive audit logs for laboratory activities along with the date and time stamp
Centralized data management	Stores all the data in a single, secure database facilitating quick data retrieval
Workflow management	Promotes better data management and resource allocation
High-configurability	Enables modification of screens using graphical configuration tools to mirror testing workflows
State compliance systems	Integrates with state-required compliance reporting systems and communicates using API
Adheres to regulatory compliance	Creates Certificates of Analysis (CoA) to prove regulatory compliance for each batch as well as batch-by-batch variance analysis and other reports as needed.
Data security & confidentiality	Masks sensitive data from unauthorized user access Cloud-based LIMS encrypts data at rest and in-transit while transmission between the client and the server
Global accessibility	Cloud-based LIMS provides real-time access to laboratory data from anytime anywhere
Real-time collaboration	Cloud-based LIMS enhances real-time communication within a laboratory, between a laboratory and its clients, and across a global organization with multiple sites

Table 1. Key functionality and benefits of LIMS for cannabis testing laboratories

Upon mapping the present day challenges faced by cannabis testing laboratories, adopting laboratory automation solutions becomes imperative. Cloud-based LIMS becomes a valuable tool for laboratory data management in cannabis testing laboratories. In addition to reducing manual workloads, and efficient resource management, it helps labs focus on productive lab operations while achieving compliance and regulatory goals with ease.

For more information on this, check out a webinar here: Webinar: How to Meet Cannabis Testing Standards and Regulatory Requirements with LIMS by Stephen Goldman, laboratory director at the State of Colorado certified Cannabis testing facility, PhytaTech.

February 7, 2018

EVIO Labs: The First Accredited Cannabis Lab in Florida

By Lauren Masko

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EVIO Labs recently became the first cannabis laboratory in Florida to obtain ISO 17025 accreditation. Perry Johnson Laboratory Accreditation, Inc. (PJLA), an organization that provides third-party assessments to ISO/IEC 17025, accredited EVIO Labs. The assessment process that lead to ISO 17025 accreditation for EVIO Labs included a thorough review of their quality management system, their capability to perform potency and contaminant testing for cannabis products.

Tracy Szerszen, president and operations manager at PJLA, encourages this international standard for laboratories to provide confidence to end-users that the test results they receive are reliable. She says laboratories that achieve this accreditation are showing they have the proper tools, equipment and staff to provide accurate testing. “It is a very critical component of the industry, and becoming accredited provides the assurance that laboratories are performing to the highest standard,” says Szerszen. “EVIO Labs has taken the right step in their commitment towards meeting this standard and providing clean and safe cannabis for the patients of Florida.”

EVIO Labs provides cannabis testing for cannabinoid and terpene profiles, microbiological and pesticides contamination, residual solvent, heavy metals, mycotoxins, water activity and moisture content. Chris Martinez, co-founder and president of EVIO Labs Florida explains that the Florida Department of Health mandates that an independent third-party laboratory tests medical cannabis to ensure that these products are safe for human consumption. Martinez says their first priority is the safety of their patients, and ensuring that EVIO Labs provides clean and safe cannabis for Florida.

Chris Martinez, co-founder and president of EVIO Labs Florida

Martinez launched their laboratory with some help from Shimadzu last year. “Our Broward lab is powered by Shimadzu with over $1.2M in the latest testing equipment utilizing LCMS technology with the world’s fastest polarity switching time of 5 m/sec and scan speeds of 30,000 u/sec with UF Qarray sensitivity 90 times that of previously available technologies,” says Martinez. According to Martinez, their licensing agreement with EVIO Labs (OTC:SGBYD) marked a first for the publicly traded company with exclusivity in the Florida market. The agreement includes proprietary testing methodologies, operating procedures, training and support.

Every certificate of analysis is reviewed by a lab director with over 20 years of experience operating in FDA regulated labs. Martinez says that EVIO has some of the most advanced technology in the industry, which provides them the opportunity to quickly provide results, frequently as fast as a 24-hour period. Martinez and his team are currently building a 3,300 square-foot laboratory in Gainesville, which is expected to be running by March of this year.

December 20, 2017

Soapbox

Cannabis and the Environment: Navigating the Interplay Between Genetics and Transcriptomics

By Dr. Zacariah Hildenbrand

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It is that time of year where the holidays afford us an opportunity for rest, recuperation and introspection. Becoming a new father to a healthy baby girl and having the privilege to make a living as a scientist, fills me with an immeasurable sense of appreciation and indebtedness. I’ve also been extremely fortunate this year to spend significant time with world-renowned cannabis experts, such as Christian West, Adam Jacques and Elton Prince, whom have shared with me a tremendous wealth of their knowledge about cannabis cultivation and the development of unique cannabis genetics. Neither of these gentlemen have formal scientific training in plant genetics; however, through decades of experimentation, observation and implementation, they’ve very elegantly used alchemy and the principles of Mendelian genetics to push the boundaries of cannabis genetics, ultimately modulating the expression of specific cannabinoids and terpenes. Hearing of their successes (and failures) has triggered significant wonderment and curiosity with respect to what can be done beyond the genetic level to keep pushing the equilibrium in this new frontier of medicine.

Lighting conditions can greatly impact the expression of terpenes (and cannabinoids) in cannabis.Of course genetics are the foundation for the production of premium cannabis. Without the proper genetic code, one cannot expect the cannabis plant to express the target constituents of interest. However, what happens when you have an elite genetic code, the holy grail of cannabis nucleotides if you will, and yet your plant does not produce the therapeutic compounds that you want and/or that are reflective of that elite genetic code? This ‘loss in translation’ can be explained by transcriptomics, and more specifically, epigenetics. In order for the genetic code (DNA) to be expressed as a gene product (RNA), it must be transcribed, a process that is modulated by epigenetic processes like DNA methylation and histone modification. In other words, the methylation of the genetic code can dictate whether or not a particular segment of DNA is transcribed into RNA, and ultimately expressed in the plant. To put this into context, if the DNA code for the enzyme THCA synthase is epigenetically silenced, then no THCA synthase is produced, your cannabis cannot convert CBGA into THCA, and now you have hemp that is devoid of THC.So what is the best lighting technology to enhance the expression of terpenes?

With all of that being said, how do we ensure that our plants thrive under favorable epigenetic conditions? The answer is the environment; and the expression of terpenes is an ideal indicator of favorable environmental conditions. While amazing anti-inflammatories, anti-oxidants and metabolic regulators for humans, terpenes are also extremely powerful anti-microbial agents that act as a robust a line of defense for the plant against bacteria and pests. So, if the threat of microbes can induce the expression of terpenes, then what about other environmental factors? I am of the opinion that the combination of increased exposure to bacteria and natural sunlight enhances the expression of terpenes in outdoor-grown cannabis compared to indoor-grown cannabis. This is strictly my opinion based off of my own qualitative observations, but the point being is that lighting conditions can greatly impact the expression of terpenes (and cannabinoids) in cannabis.

A plant in flowering under an LED fixture

So what is the best lighting technology to enhance the expression of terpenes? Do I use full spectrum lighting or specific frequencies? The answer to these questions is that we don’t fully know at this point. Thanks to the McCree curve we have a fundamental understanding of the various frequencies within the visible light spectrum (400-700nm) that are beneficial to plants, also known as Photosynthetically Active Radiation (PAR). However, little-to-no research has been conducted to determine the impacts that the rest of the electromagnetic spectrum (also categorized as ‘light’) may have on plants. As such, we do not know with 100% certainty what frequencies should be applied, and at what times in the growth cycle, to completely optimize terpene concentrations. This is not to disparage the lighting professionals out there that have significant expertise in this field; however, I’m calling for the execution of peer-reviewed experiments that would transcend the boundaries of company white papers and anecdotal claims. In my opinion, this lack of environmental data provides a real opportunity for the cannabis industry to initiate the required collaborations between cannabis geneticists, technology companies and environmental scientists. This is one field of research that I wish to pursue with tenacity and I also welcome other interested parties to join me in this data quest. Together we can better understand the environmental factors, such as lighting, that are acting as the molecular light switches at the interface of genetics and transcriptomics in cannabis.