About the guest: Iain Oswald, PhD is an organic chemist and Director of Research & Development at Abstrax Tech.
Episode summary: Nick and Dr. Oswald discuss: plant chemistry; marijuana strains and their aroma; the chemical basis of cannabis aroma; terpenes vs. non-terpene volatile organic compounds; and more.
Related episodes:
Marijuana, Plant Chemistry, Terpenes, Volatile Sulfur Compounds, Cannabis Industry, What Pungent Weed Smells Like & Why | Iain Oswald | #114
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*This content is never meant to serve as medical advice.
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Episode transcript below.
Full AI-generated transcript below. Beware of typos & mistranslations!
Iain Oswald 3:46
Yeah, thanks for having me. Nick.
Nick Jikomes 3:47
Can you tell everyone a little bit about who you are and what you do?
Iain Oswald 3:51
Sure, yeah. My name is Dr. Ian Oswald. I am the research and development director here at abstracts tech, which is a cannabis research and development technology company here in California. And so we do things ranging from cannabis extraction, all the way to flavor development for vapes and other types of products, beverages, those sorts of things. We've actually moved even beyond cannabis now looking into hops chemistry, because they're very similar. And yeah, making some waves over in that field. But the majority of our work is in cannabis. And, you know, we try to publish research when we can on some of the cool stuff that we discover. Yeah.
Nick Jikomes 4:35
And you've been working on things related to flavor and aroma. Can you give people just sort of a general picture of cannabis aroma in terms of, you know, how variable isn't how important is it to consumers? How do people sort of in the cannabis industry or in this general realm, think about cannabis aroma and why it might be important and where it comes from?
Iain Oswald 4:59
Sure. Yeah, so if we start kind of from the general public, so the really broad image, I'd say that a lot of people, especially non consumers, associate cannabis specifically with that sort of, skunky aroma that, you know, it is kind of well known for. And, you know, we published research on that understanding that sort of chemistry back in 2021. And we talked about that the past as well. But the truth is, is that there's much more to it than just that aroma. And why its diversity occurs is, you know, it hasn't been well known. A lot of people within the industry, the scientific community of cannabis has really focused on terpenes for the broader part of the last few decades, and they've done great work as far as kind of understanding that chemistry and how might translate to maybe some of the effects of this specific strains as well as, you know, kind of chemo typing as far as their aromatic qualities. But the, the nitty gritty is that there's much more to that.
Nick Jikomes 6:05
So, so most people who think about this stuff when we think about terpenes, so these are volatile compounds that smell, they all have usually a distinct smell. They are common in the plant world. So you know, you see him in cannabis, you see him in fruits, you see him in vegetables, it's sort of an aromatic communication, language for plants, you might say, and we know that like, you know, citrus fruit fruits, smells citrusy, largely because of the presence of certain terpenes. We know that you know, other fruits, vegetables, plants, a lot of their aroma comes from specific terpenes or specific combinations of terpenes. Many of them are named for this reason. So you know, pinene is a terpene, you find it in pine needles, it gives them their piney smell. And so I think the presumption has been that, well, you see a lot of terpenes in cannabis, and therefore, the aromatic diversity and distinctive smell that you get from different strains of cannabis are presumably coming from terpenes. But based on the research that you've done, that seems to be called into question to some extent.
Iain Oswald 7:09
Definitely. And the truth is, is this research has kind of fallen very similar path to that of wine, as well as beer and hops and grapes. And we're kind of cannabis is next in line and understanding that, you know, the most plentiful compounds that are volatile and give flavor may not be the most impactful as far as their their odor characteristics or their flavor. And so to your point, yeah, terpenes are found all over the place. They're they're ubiquitous in nature, there's, I think there's over 400,000 described within the the terpene class, which is ranging from mono terpenes to SESQUI, terpenes, to then died terpenes and even larger things than that.
Nick Jikomes 7:52
And I think it's, you know, thinking about abundance is logical. So after, yeah, after the cannabinoids, like THC, the most abundant things you tend to find in cannabis resin are the terpenes. And in parallel to that, we know that terpenes are aromatic, they are responsible for the smells that we smell in the plant world much of the time, and therefore it makes perfect sense to think that they're going to be the primary drivers of these distinctive cannabis aromas that we'll talk about. But sort of what you just alluded to is that, you know, the abundance is not necessarily a good index for importance, you can have highly, highly potent compounds that are present in tiny levels that actually drive a lot of flavor and aroma. And maybe it may be a good hook into this for people that might be familiar as if you just think about cooking, like if you cook food at home, doesn't take very much garlic to have a very large impact on the smell and the flavor of whatever you have in the dish. And so the sometimes the tiny ingredients have this outsized impact.
Iain Oswald 8:51
Yeah, definitely. And you know, we actually alluded to garlic in our initial paper reporting into sulfur containing species that make cannabis skunky for that very reason. And they are coincidentally kind of chemically very similar to which is interesting. But yeah, you know, the other thing, the other component here is that, you know, cannabis has been difficult to study period from a legal standpoint. So academics that might have more sophisticated sophisticated techniques than other folks that are in the industry don't have access to it, or if they do have access to it, they might not have access to what is representative of the most modern varieties on the marketplace. Right. And so that's another thing that I want to kind of point out here is that as as the years have gone by, you know, the decades the probably centuries, cannabis, the aroma of cannabis has changed throughout that time. Right. And it may have been more dominant in terpenes, specifically in older varieties than they are in more modern varieties as people have bred for the specific flavor nuances. Well, now we start to see other things besides terpenes because something more important. And that's why on the marketplace, you can have things ranging from these very, very sweet varieties, which it'd be hard to find a terpene that has the aroma characteristics that would suit those. And on the other hand of the coin, other side of the coin is, there's also varieties of cannabis that are very savory now, which is really interesting. Because when people kind of think about, well, what is modern quote unquote, exotic cannabis, a lot of people think of really sweet, but actually, there's this whole other kind of side over there that is beyond what people would kind of call traditional sort of prototypical cannabis.
Nick Jikomes 10:35
And so I guess, by working on abstracts in the private sector, you're sort of in a unique position, I guess, because on the one hand, you guys have the resources to use and implement, you know, technical methods that are, you know, cutting edge basically that, that you would get only in like a hardcore research lab. But on the other hand, you also have access to the real world cannabis that's out there being used by actual people, which a lot of academic research labs don't have access to. So you sort of have both pieces here. Exactly.
Iain Oswald 11:07
And to be honest, I, you know, they're both necessary, right, especially for the chemistry that we've been doing the analytical chemistry to find these really low concentration compounds. But I would almost argue that the, you know, the source of cannabis that we're getting is actually just as important, like you just said, and you know, I don't know if a lot of people realize this, but for a long time, the only way that people in an academic setting such as a university could conduct research on cannabis, they would have to go through, I think was the University of Mississippi or Mississippi State one of those to where they actually had fields growing. And it was the only essentially, legal way that people could grow cannabis, and then analyze it. And not to say that, you know, they're growing booth, if you will, but I am highly doubtful that what they were growing there, it was representative of what people were doing in California, you know, over the last few decades, and there's actually been papers that have verified this, that the varieties available to academics is not representative chemically. To that on the marketplace. And so, to your point, yes, we're, I think we were perfectly positioned to, you know, take advantage of our you know, this, this investment into really powerful analytical equipment, but also having access to some of the most exotic or, you know, super, just really unique smelling varieties out there to understand well, why why do they have those characteristics? And so let's
Nick Jikomes 12:36
maybe talk briefly so we you know, you've been on the podcast, before we've talked about this work. Let's just briefly summarize your last paper for people in terms of the major findings, and to give them a sense for like, how you're actually doing this. So what did you find before and how did you find it? Sure.
Iain Oswald 12:52
So the previous publication we did in 2023, was aimed at looking at essentially, well, what is the chemo diversity in modern cannabis, across a wide range of varieties, right, we wanted to sample everything that we possibly could as far as aromatic characteristics. And so we worked with some cultivators in California, such as 710 710, labs, they're actually co authors on that manuscript. And they helped us kind of pick out like, yeah, these would be great varieties to pick, they have very unique characteristics, these other ones are completely different. And so we ended up procuring 31, hash ice hash rosin samples, which the reason we went with rosin, because people have asked is because these compounds are in such low concentration, that when we do do our analysis, it's really hard to see them period. But when you make a concentrate, such as rosin itself, you're concentrating all those analytes down, so it's easier to kind of see what is real and what's not down there near the noise level. And so the equipment we're specifically using is called two dimensional gas chromatography. And this instrumentation essentially, is a very powerful way of decomposing a complex mixture of compounds into data that we can actually go in and look at all of those individual components. And so we've tweaked our methods between using rosin and then also just our methodology internally to basically try to raise up the signal as much as possible. So we can see what are these really low concentration compounds that might be existing that folks have ignored for a long time? And part of this was born out of your previous study, Nick, where, you know, in your work, you called out specifically these clusters, these terpene clusters? And I remember reading this and thinking well, it's, it's curious that there are varieties that I know have very different aroma characteristics that cluster into the same sort of, you know, statistical grouping, and I thought this is great because it was windy. up with what we were actually finding on our side here at abstracts. And so in essence, what we did is we took all these samples, we ran them on our instrumentation. And then we also did a sensory panel, meaning we took the human element, the human response to the samples. And so we got seven folks from our team to systematically go through these samples and literally do a sniff test, what does what does this variety smell like? And describe it to us. And what we found was that, in essence, the terpenes, that so many people in the industry have been focused on, often will may remain remarkably similar, even when the aroma characteristics are very different. And that right, there was kind of validation that, you know, something a lot of people had been thinking in the industry, they've been calling out, yeah, there's probably these other chemicals on that in there. But there was never any direct evidence of a which ones were most important. But then also which ones are their period. And so during that study, during the analytical portion, using the, you know, the chemical tools that we have, we happened upon some really interesting new compounds that ended up driving the aroma characteristics of these very, very strongly. And so two of those that I'll call out, are these tropical VOCs, tropical volatile sulfur compounds. And so these would be again, kind of in that class of volatile sulfur compounds that the skunky gassy compounds are in, but they're chemically unique, their functionality is all specific to itself. And so this is the three mercapto Hexcel functional group. And cannabis produces this in many varieties that are modern, it's in tangy, it's in mimosa, anything that has a very intense sort of citrus or grapefruit, you know, a very tenacious sort of tropical illness to it. You're going to find it in those,
Nick Jikomes 16:54
and so and so sulfur containing compounds. So you're not talking about a terpene here, but just sulfur containing compounds in general, tend to be very potent in their smelliness. Right? Oh, very much. So
Iain Oswald 17:06
yeah, the human nose has adapted well, to sulfur containing species, probably evolutionarily. A lot of things you probably shouldn't eat probably have sulfur. And that's the reason why we're so fine tuned to it.
Nick Jikomes 17:18
And that's where like, like, literally the animal skunks, their perfumes contain some of these types of chemicals, right? No,
Iain Oswald 17:25
yeah, definitely. In fact, the primary component of skunks aerosol is chemically identical to the major component in cannabis, which is parental file. The only difference is cannabis has a double bond a skunk doesn't. And so you can imagine, you know, it's, it's a symbol, but you're basically taking a few hydrogens away, right? Yet. Yeah, that's why it has a slightly different aroma. But still very much very,
Nick Jikomes 17:52
so interesting. Okay, so So basically, you guys are using instruments that are highly sensitive, they're more sensitive than what you would even see in a typical commercial cannabis lab, are the most sensitive instruments you could use to do this type of work. You've applied this to cannabis products to looking at strict concentrated versions of strains that are actually out in the real world being used by people. And you have found that you can sort of map the aroma characteristics that come from humans. So you have people smell this stuff. This one smells sweet, this one smells savory, and so forth. And then you can actually correlate that very well to the underlying chemistry, and what are some of the major differences in the aromas? Is it like a sweet versus savory thing? How should people think about the aroma space here?
Iain Oswald 18:35
Yeah, so we were, we were actually kind of struggling with how to partition the sort of aromas. Generally, when we were first writing this manuscript, and when, when I was first kind of drawing it all up, and we were trying to think, well, how can we kind of, under you know, understand this in a way that's relevant to a consumer, but still makes sense. We originally thinking of doing like, an aroma wheel. But then when we're talking to some folks who are on the panel, they're like, Well, you know, the wheels are great, but a, they tend to be kind of recursive, and they come back and you have, you know, to two terms that might be kind of at odds against each other. And so, and even before that, you know, when I originally was conceiving of kind of how to partition these varieties, I was originally just thinking well, prototypical, you know, maybe like, oh, geez, Jack rares, older varieties like that. And then just really sweet varieties. And so those would be these modern exotics like skittles or runts, those sort of things. But one particular user when he was doing the panel, he was smelling GMO, which is a shorthand form for garlic, mushroom onion. It's named that because it's literally so savory smelling that that's, you know, how they got their name. And he said, Well, Ian, this isn't Prototipo Go and it's definitely not sweet. And so that's when I realized, you know what, like, there's a savory side to cannabis as well, that people, you know, it hasn't really been called that specifically. But I thought, you know, this is the perfect opportunity to, you know, correlate the chemistry we're talking about to these specific aromatic notes that don't fit into the other two. And so are our spectrum. Our cannabis aroma spectrum is what we call it goes from sweet to prototypical to then savory, and it really does partition out kind of everything that we've happened upon within that paper and within our lab really well. And you can, we can literally map these onto the spectrum. Now it's really cool, because you can comparatively say like, analytically, like, yeah, this thing is, to the human knows, more sweet than this other thing? It I think that was a really cool novelty of the paper that we came up with, for sure.
Nick Jikomes 20:51
Yeah. And so so one of the things, you know, that you mentioned earlier, it's been a little awkward for people in the cannabis world to explain is, you know, we think terpenes are responsible for the aroma that makes logical sense. And yet, as you mentioned, you know, when you look at the data that I and others have produced, when you just go into a grow facility, and you know what the basic terpene profile is, because they have to get the stuff tested, you often find that things with very similar, nearly identical terpene profiles, nonetheless, smell very different. And typically, the response you get to that is, you know, people kind of wave their hands and be like, well, the slightly different ratios of terpenes can do complicated things in our nose. And it's complicated. But actually, the answer, it seems, turns out to be much simpler, which is they smell different, because it's other compounds that are actually accounting for the difference. You also mentioned, so, two different strains, similar terpene profile can have very different aromas. And that's because you've discovered that these other types of compounds that contain sulfur and things like that are actually what's driving the aroma difference, not so much the terpenes. There's also, you know, not just comparing strains with similar terpene profiles, but very often in cannabis. People do what's called fino hunting, so they actually cross two plants together, they will produce offspring, they're all very genetically related. They're all brothers and sisters, basically. And yet, they can look very different, smells very different, and so forth. And so even plants from the same cross can smell very different, even though their genetics are highly similar. And I think that was something that that got you got you to your next paper. So can you start to talk about that?
Iain Oswald 22:27
Certainly, yeah. So, you know, the, our first publication set the groundwork for like, what is kind of the, the universe of chemists chemistry for cannabis, aside from terpenes is on a broad perspective. But what we what we became interested in is, to your point, what is the chemistry look like the diversity as far as genetically similar cannabis? And why is this important? Well, you hit the nail on the head. This is literally how people select new varieties, right, the reason why people select baccio, 41, gelato, 41, and gelato, 33. And not gelato. Number two, is because it had the characteristics, oftentimes growth characteristics, yes, but many people nowadays are selecting almost primarily for aroma, right, and looking for what smells the most unique. And so the fact that you can have, you know, the same process, and so the same parents produce, in our paper, we were just looking at five, so that's not even a large sample size. Yet, what we found is the chemical diversity there can be very specific, that relates very well to the aroma characteristics. And guess what, the terpenes are almost identical. And you know, this, this just goes to show that, sure, chemically, they are similar when you're not looking deeply, but there's a reason why people select this fino over another. And if it's from an aromatic perspective, it's because of this really specific chemistry that we're talking about. And within that paper, lo and behold, it actually one of the major components was the samples were Starburst 36 from 710 Labs, there were five fino finos from that. And the major differentiator ended up being essentially the tropical VSC which again, contains sulfur, very highly odor active, and their distribution correlated with other changes between the groups that were said to be more savory leaning versus more you know, straight citrus and tropical. So
Nick Jikomes 24:29
Starburst 36 You said was the strain or the crossing so you cross the fence together we're gonna call everything produced from that Starburst 36 But there's variety there just like you know, if people if people have big families, you've got brothers and sisters, even though you got the same parents, you know, you're you have different heights, you have different hair colors and so forth. So these plants are different and then there's selecting you looked at five different phenotypes, five different siblings, basically from that cross, and you're saying that some of them smell sweeter, some smell more savory, what what was aroma sort of differences, what did that look like?
Iain Oswald 25:02
So the major differences, two of the varieties were classified as being much more intense tropical, sweet citrus, right. And so that would fall into that sweet exotic side of the spectrum. The other three, were two of them were specifically much more on the savory side. And interestingly, descriptors such as cheese came up for those two, and I'll get to that in a second. The third one was kind of in the middle, where it didn't have the same characteristics of either them, but it kind of partitioned into the latter half, the a little bit more on the savory side. And the cool part about that is that was chemically, but when we map that to the sensory panel that we did for this study, as well, they partitioned out almost the very, very well, like it was very clear cut clustering of the chemistry that mapped onto the aromatic qualities of the samples. So some of these things
Nick Jikomes 26:00
smell sweeter, more of a tropical type smell, some of them smell more savory or cheese, like, then you've got this other one that smells, you know, somewhere in the middle, let's say, what so naively, right naively before you know, if you weren't familiar with your work, you might think, okay, the tropical ones probably have high limiting levels. And so everyone's probably have high, high levels of a different terpene. What were the terpene profiles that you actually found?
Iain Oswald 26:23
Yeah, so they were all very consistent. So they're all caryophyllene. Rich, which is contrary to the paradigm that, you know, if it's very citrus, it has to be very high in limonene. Right, that that data right there, we have a graph to show you the top 10 terpenes, I think, for all the finos. And they look very, very similar just in their bar plots. But that that goes against everything that, you know, people in the cannabis industry for marketing have been saying for the last 10 years, which is that, yeah, I love these varieties, because it has a lot of limonene because it has very strong citrus notes. Well, here we have five varieties all have some amount of citrus, yet none of them have limonene as the dominant terpene. And so I think that was our first paper really showed that that This to me was like kind of the nail in the coffin that limonene is, you know, fairly benign when it comes to the the intense sort of citrus notes that people talk about in the context of cannabis.
Nick Jikomes 27:25
So just to summarize, so far, Starburst, 36 is the strain, but you're looking at five different phenotypes, five different siblings that come from the same cross, we're talking about plants that are genetically highly similar, but not necessarily identical to each other. They are grown under the same conditions, all of the processing of the stuff you're analyzing is done under identical conditions. So we're sort of controlling for some of the potential compounds that might come from those things, we get, you know, even though these are phenotypes of the same strain, we're getting some that are more sweet and tropical smelling some that are more savory smelling. And the terpene profiles look similar between all of them. And so take us a little bit deeper, what were the specific compounds that were responsible for the differences between the more tropical smelling ones and the more savory smelling ones.
Iain Oswald 28:11
So there's, there's a few main differences. The first was the more tropical varieties were had the greatest concentration of all of the, what we call a Tropicana sulfur compounds, these are these tropical DSCS. And these include three of mercapto hexanol, through mercapto, hexyl, acetate butyrate. And we actually newly reported in this manuscript, the hexanoic. So there's a whole family of compounds that kind of fit within this sort of tropical passion, fruit, grapefruit, heavy citrus, sort of family of compounds within cannabis. And depending on those levels, you can get more of that, or less of that. So what we found, yeah,
Nick Jikomes 28:53
is it fair to say that so there's, there's a group of these Tropicana sulfur compounds that are like chemically related, they have a similar chemical makeup? Is it fair to say, based on your past work in this work that, you know, if you sort of very, very the levels of each of those, you know, you're gonna get something that's kind of tropical smelling, but one of them might be a little bit more citrusy, a little bit more grapefruity, and so forth? Yeah,
Iain Oswald 29:14
exactly. And a perfect example of that is, our understanding of all this chemistry is, you know, evolving all the time, as we mentioned, new samples. But what we what we have identified is the three mercapto, Hexcel butyrate. And then the hexanoic might tend to be much more citrus forward, so almost grapefruit like, whereas the three mercapto hexanol, and then the three mercapto, hexyl. acetate, they actually lean a bit more tropical, meaning that they present like passion fruit, maybe pineapple, some of these a little a little less defined as far as the kind of aroma characteristics.
Nick Jikomes 29:56
And then what about the savory samples? What was the chemistry like there?
Iain Oswald 29:59
Yeah, and This is what was so cool. So I was actually one of the participants on the panel. And you know, it's all blind coded and everything. And what was so cool about this was I remember distinctly after smelling one of these samples that there was two that I called out to be cheesy, and those were the ones that partitioned the way towards savory. I remember smelling this and thinking, this smells like Stilton, Stilton, cheese. I don't know if you're familiar, you know, but it's the stinky blue cheese. And it was that sharp tenaciousness that you know, it's not the same as cheddar cheese, it's not the same as you know, you know, a little bit more mild cheeses. And when we go and look at the chemistry, it was those ones ended up having a much lower levels of the these Tropicana sulfur compounds that make the trip on the tropical notes. But on top of that, there, we did identify some fatty acids. And these include autonomic acid, and decanoic acid. Both of these are key ingredients in various cheese products, dairy products, they're ubiquitous in nature as well, but they're rarely described in the context of cannabis. And they're definitely not described in the context of aroma of cannabis. So that would that was really cool. And, you know, I will say it kind of validated my nose, I
Nick Jikomes 31:14
felt so that was fun. I mean, it makes good logical sense, right? The savory cheese like aroma is coming from something like a fatty acid, which is what you would expect. Exactly,
Iain Oswald 31:24
yeah. And I mean, decanoic acid, I think one of the descriptor terms people often give it is rancid, right? It's almost like a rancid butter or rancid cheese to something that's kind of gone off. And all of this is, you know, important. When it comes, sorry, the concentrations are important here, right? They are they weren't low concentrations, but it's something that has high odor activity, then again, just like the volatile sulfur compounds, it doesn't necessarily matter, the human nose can pick these up. So that was really neat. And the other thing, just from a chemo typing standpoint, and almost like an aroma typing standpoint, here was something that was very cool between the two varieties, the two phenotypes that were very tropical, and then the remaining three, the three that had less tropical notes, we detected, you know, an appreciable amount relative to other samples of indole, which is a heterocycle. Right? So indole, we previously reported in the paper and 2023, to kind of correlate more with the prototypical, definitely leaning towards the savory exotic side. And I thought that was fascinating that there's this sort of very specific and abrupt partitioning where it was like, I think it was the last figure in our paper where we actually circle indole in the three chromatograms, and highlight how it is very obvious in those three that lean protein, prototypical savory, and not in the other two, which makes us start wondering, is there some sort of trade off biologically, you know, biosynthetic, Lee, between indole? And maybe some of these other metabolites that are important? Yeah. Yeah,
Nick Jikomes 33:05
I think that's, that's likely. So we know, from, you know, we know cannabis consumers care about the sensory qualities of the products that they're interested in, they care about how it smells, and how it tastes and so forth, then they're also interested in the effects the psychoactive effects, and those two things may be or plausibly related to each other, but ultimately, right, they want to know, you know, how is how is this thing going to affect me. And before your research, I mean, even even after your research to this day, you know, the presumption is still that A, the aroma is dictated by terpenes. And be, you know, the so called entourage effect, which, which actually hasn't been demonstrated very clearly at all, in my opinion, between terpenes and cannabinoids, the idea is, you know, the terpene profiles dictating the aroma, and it's modulating the effect of THC. So by knowing the terpene profile, you can know the sensory qualities and the effects. And therefore, we should be able to label products, knowing these things, and that will that will predict how people will feel when they consume it. So the idea would simply be, well, let's just show people say the top three terpenes or something like that, or group them based on terpenes. And that is the appropriate way to label and categorize cannabis products. What does your research say about the potential effectiveness of that general approach?
Iain Oswald 34:31
I think to your point, Nick, there's a lot of there's a lot of marketing around the trage effect right now. And I think we're simplifying things down without really having hard evidence, at least not hard enough for myself as a scientist to really fully believed. But that's not to say that there is something to it. It's just we don't have the full chemical picture yet. Right. And, you know, that's why I'm excited. About this new research we're doing, yes, these are in very low concentrations. But, you know, combined together, could they be doing something important, biologically, physiologically, and something I'll mention that I do think is interesting that cannabis produces is, you know, it does produce indole, that people are, you know, inhaling when they have these certain products. But it also produces scatto, which is in those extremely savory varieties. And the and the reason I bring these two up in particular is because they have these heterocyclic rings, and heterocycles are found ubiquitously in nature. They're a key core functionality, chemical functionality, and tryptophan, and melatonin and psychedelic drugs. That's not to say that they themselves have those characteristics. But, you know, it would be really interesting for us to now look at this new chemistry, especially the chemicals that kind of might have correlation to known compound classes out there, and maybe do some molecular dynamics or docking studies to see, does this have an affinity, maybe indole has a slight affinity for the allosteric site on CB one, right? Maybe that that influences how THC binds those sorts of things. But you just you can't do that unless you have the knowledge of what is there in the first place. And so I think that our research i I'm hoping other folks will take up, you know, especially more on the medical or the, you know, the kind of biological aspect to see, do these things sort of modulate actual physiological responses. And if so, like, maybe maybe, then we could start getting into tailor made and truly accurate sort of effects based predictions.
Nick Jikomes 36:39
And so given that these things are present at such low levels, these Tropicana sulfur compounds, these fatty acids, these other things that seem to be very important for the aromas that you've identified their president very, very low levels, which is why you had to use concentrated samples in the form of hash rosin to do the study. Given that fact, and given the additional fact that most companies out there making cannabis products, most labs out there doing testing for the industry, they don't actually have the equipment that you guys have, they can't actually measure and detect these things. So is there any way any plausible way to actually use this type of information to communicate something to consumers about the aroma profile given that no one can know except you basically can measure these things? Yeah.
Iain Oswald 37:26
And I mean, that is that is definitely the struggle, right is okay, we've made these cool discoveries. But how can we bring this to the broader public? And so first, first is education. Right. So that's, that's the whole point of these peer reviewed papers is to educate other people, both scientists, and you know, people interested in cannabis science that might not be scientists about this. But we are actively working on trying to translate some of this complexity onto less complex analytical systems. And so these would be things that people are using in typical analytical testing labs. And so we've had definitely some sex success there. As far as certain compound classes go, I will mention that one of the benefits of the instrumentation we have that would translate fairly easily to a traditional gas chromatograph is this sulfur chemiluminescence detector. And so we've actually been developing this and I gave a talk at AOTC last year, but some of the research we've been doing, at least detecting the sulfur containing compounds using this detector, because the only thing that detects is, does this compound have sulfur or not. So it simplifies the data greatly. And when you lose that second dimension that we have, the data is even more complex, so that that detector is proven very valuable, in the context of trying to develop a method that, you know, if a testing lab just had this sed could potentially actually start reporting these very important compounds. And so then, the other the other aspect is that of that, that I'll mention is reporting, reporting. ppm, if you will, on a box, you know, micrograms per milligram. I personally don't find it very conducive to be are very useful in any way to understand will I like this product or not, you can have very high concentrations of terpenes like 4%, on flower, that they're typically typically enriched, which is funny, but they're not as loud as something that has less terpenes because they're lacking those really low, abundant, potent VSTS that we're talking about. And so that can lead you astray. Right. So
Nick Jikomes 39:36
that's, that sounds problematic from the standpoint of, you know, a proxy for quality or at least a Roma pungency, that's evolved in the industry is simply to look at the total terpene content, the presumption being more terpenes more pungent, whatever the specific smell might be. It sounds like you're saying that's a that's not going to work? Yeah,
Iain Oswald 39:56
I mean, or at least it could be refined greatly. Let's put it that way. And, and part of this, again is education. You know, if I, if I did a class where I had a group of people, and I had them sniff to the terpenes, and then I had them Smith through these VOCs, I guarantee you, every single one of them would say, oh, that's what I'm looking for those VOCs is what I'm looking for those other terpenes, like, those just, they kind of smell just like generic plants, they don't smell like cannabis. And so I think that's a big part is translating this into something that people will find, you know, not only interesting, but useful. And so to that end, I mentioned, having having a percent on there, I don't think is very useful. But what we're doing internally, is we're taking all this data we're acquiring internally, both on the GC and we now do basically a century panel for almost every single sample that comes through our lab, we're going to take all this data, and we're modeling it to look for relationships between the chemistry that we're already pretty, pretty well aware of what's going on. But can we create predictive models now that maybe from a scale of zero to 100? Be like, okay, yeah, this product, at least at this point in time, has a gas factor or a skunk factor of 95, you know, it's going to be of a certain potency for that aromatic quality, because, you know, it was analytically tested and fitted to this model, we could do that with potentially tangy, right, as far as a sort of tropical notes. And so that's what's so cool about all this is that knowing this kind of subtle chemistry can allow us to actually devise metrics that are truly useful for the consumer, if they care about aroma, as far
Nick Jikomes 41:37
as quality, and how important is the time component here. So these things are very volatile, they float away very easily, they're present at low concentrations, and yet they have a huge effect on the perceived aroma. How does this relate to something like freshness, and you know, if you've got a jar of cannabis at home, you know, most people who've, who've had the experience know that on day one versus day five versus day 10, that that aroma does change, are these things a good indicator of freshness,
Iain Oswald 42:07
oh, incredibly, and in particular, the prenylated volatile sulfur compounds that we discussed previously, there, they are the most volatile, yet they are probably what most people are after, when it comes to the quality indicator, you know, through their nose. And, you know, just from a recent experience, we're doing a new study with some folks on some genetics, essentially. And I had the great luxury of harvesting some flour and curing it. And I don't have a fancy setup where I was. And so I, I had to use the brown bag method. And it was incredible how the aroma changes through that process. And I'm, I'm definitely not an expert. And I bet you on top of freshness, it's also probably a really great indicator of how good are you at your craft, like if somebody gets if something gets to the store, and it still smells very pungent. If if somebody else like myself, a novice was given the task of, you know, drying and curate, and you know, that whole process, there's no guarantee that it would come out the same. And so I think actually, that's going to be that is actually a follow up study we're working on right now, which is not necessarily the curing aspect. We unfortunately missed out on that. But once it's in the packaging, how does packaging affect this? Right? And so we're doing that right now where we're going to measure over the course of about six months. And so it should be really interesting, because it'll, again, a lot of this, I think people have suspected or they've known, but there's never been hard evidence to say, well, what is the rate of decay for these VOCs versus terpenes. And I think what we'll find is, they're going to be much more rapid, as far as their loss. And to your point, Nick, quality, you know, that quality impact could be more rapidly lost. And so huge implications for people who care about quality and producers who care about quality.
Nick Jikomes 44:02
Yeah, and it's remarkable how how how good the human knows is actually when when you start thinking about this, like, I've met many people in, you know, in my personal life, and in my time in the cannabis industry previously, where they can tell you in a millisecond, if something is truly fresh, or it's been sitting out for a few days, they don't necessarily know, they might not have any idea what they're smelling what the chemistry is, but like they can tell you reliably and they're like, oh, that's fresh, and that's been sitting out without being told that ahead of time.
Iain Oswald 44:33
Yeah, definitely. And, you know, I mean, I think, I think that sort of training comes pretty quickly, to be honest. But again, you have to be exposed to that. Right. And I think that's the major benefit, you know, if you do home grow or, you know, you can get what is would be considered really high quality cannabis, you know, you will know immediately like, Oh, this is different from everything else that I've had, right? And there's so many variables that go into the retention of these compounds. I mentioned, you know, I did track one variety, I took three data points through this Kurian that I did two weeks ago. Again, just brown bag method. But it was it was fascinating because I could literally see, there was a specific VSC that appeared. And it I could, I could smell it, it was because it was it was an OG but it was beyond OG was much more savory. And it's not. So it's not just pronto file, there was another one in there that leans a bit more on the savory side of kind of almost like truffles or garlic to be honest. But as as a keyword, and again, I'm not an expert, but nonetheless, it changed to my nose. And it went away fairly rapidly. And I thought that was really interesting for two reasons. One, does that mean, if you want to try to capture that aroma, and you're making concentrates, you want to harvest or you know, maybe process at a specific point in time. But second, is there a way to maybe if I had been carrying more correctly, if you will, could that have been retained more so so you know, it lasts beyond just the two three weeks that it was kind of there. But it was really fascinating. And again, it was cool to validate chemically what I was smelling? You know, in the data.
Nick Jikomes 46:18
Interesting, um, you mentioned some of the follow up work you're doing? Is there anything that you want to reiterate about this last study or anything that we missed that you think is important that you guys found? I
Iain Oswald 46:29
mean, I think the biggest one is if you are a cannabis breeder, because I think to be honest, the the biggest story here, a lot of a lot of people are focused on the acids, because, you know, implications for cheese aroma, and I think that's cool. And all, but I think the broader picture here is, you know, if you're a breeder, using analytical techniques at testing labs may only lead you astray. Or at the very least, it'll leave you confused, because, and I've seen this before on on Instagram, or social media, where readers will say, Yeah, I have these two things tested. One smelt like this one smell like that. But the Terps all look the same. And then, you know, they're shaking their head, what's going on? And so, I think, you know, analytics aren't, aren't there yet, as far as really helping, breeding unless you're fino hunting for new terpene profiles, which, you know, that's, that's perfectly fine. Right? It'll definitely be helpful there. But if you're looking for in the context of something where the Terps look the same, but smell different than you know, our paper really shows that it's going to be difficult to kind of do. Yeah, and I think anyone, if you don't hunting for new terpene profiles, I
Nick Jikomes 47:39
don't think anyone is actually doing that for the sake of the terpene profile. I think they're doing it insofar as they believe it's going to tell them or dictate the aroma, or the effects. But your work is really showing that that could very well lead you astray if you're using a terpene centric mindset to do that selection.
Iain Oswald 47:56
Yeah, no, exactly. I mean, that's literally what the main point of the story is, is that, you know, breeding is, you know, it's still an art more than it is, I'd say, like a hard science as far as understanding these nuances. And the truth is, the nuances what people are looking for, right? You know, a lot of times these differences are subtle, but you know, they're detectable. And it's how people make decisions. And so, yeah, I think just, you know, this sort of science just kind of helps, kind of show us that we don't, we're not quite there yet, as an industry to take advantage of some of this, you know, this new science, but um, you know, hopefully, hopefully, in the near future, it could get there.
Nick Jikomes 48:39
Well, thank you for your time. Yeah, and this is fascinating stuff you've been on before. So I'll just point people to, you know, I've got another episode up with you, where we get into some of the findings that you guys came up with last year to do with the skunky aroma and things like that. So these two episodes kind of go go together in a complementary fashion. Anywhere, how do people find the study or find your work and that stuff? Sure,
Iain Oswald 49:02
yeah. So if you're looking directly for the peer reviewed study, you can go to ACS omega, so it's the American Chemical Society, it's a journal there. As well as you can go to abstracts, tech.com, and we have a science section. And we have done white papers to kind of decompose all of this. There'll be a forthcoming one for this fino typing sort of this this more modern work that we just did a few months ago. But yeah, if there's a lot of great resources on our website, so I recommend people checking those out. It kind of distills down some of this complex science into much more digestible sort of formats, especially if you're not, you know, an analytical chemist like myself. All right, Dr. Ian oswaal. Thanks
Nick Jikomes 49:45
for your time. Cool. Thank you, Nick. Let's just kind of pause here for a minute.
Yeah, so what I want to try and do now is cuz Lee, for Leafly purposes, if they put it up, so I'm gonna, I'm writing an article about this, I'll share it with you to give you a chance to just make sure I've got all the facts, right. Probably Monday, you know, they'll probably embed something in that, but then also like having shorter things like for their social is is what they want, basically. So in a moment, I want to just, you know, I'll sort of briefly introduce you or have you introduce you. And then I want to just do the most sort of concise summary of the work we can. It doesn't, you know, it doesn't need to be perfect, but basically, like, what you did, what you found and what the implications, you know, the sort of the punchline should be what the implications are for consumers.
Iain Oswald 50:50
So, yeah, that sounds great. And just really quick, because I don't want to forget I probably will. Our marketing team is like down to like, rebroadcast you and everything so Is it cool if I just get you in contact with Brandon our social guy? Yeah, that's Yeah, cuz he'll, he'll, he'll spam your, your podcast, our audience and whatnot, all that stuff. Okay, great.
Nick Jikomes 51:12
What's your what's your official title? Again? Director of Research and Development. Okay. And your PhD is in organic chemistry effectively, okay. Director of Research and Development, okay. All right. I'm here with Dr. Ian Oswald. He is the Director of Research and Development for abstracts tech, he has a PhD in organic chemistry. And he is one of the major experts on the chemistry of cannabis. And he's sort of at the cutting edge of what we're learning there. And understanding some really cool stuff that gets us thinking about where the aroma of cannabis comes from. And one of the exciting things that his team has found is that often doesn't come from terpenes. It's coming from new compounds that they're just discovering. And so in, what was this latest study that you published? And what were some of the major findings, their
Iain Oswald 51:57
most recent study was aimed at understanding how do does phenotypic diversity correlate with chemical diversity? Is there a broad range of chemistry that's different between siblings of cannabis with the same cross? Or is it fairly narrow? And within there? Are those aromas that might be detectably? Different? Are those coming from terpenes? Are they coming from something else?
Nick Jikomes 52:26
And so what so you looked at genetically similar phenotypes of the same strain? So they have very similar genetics, they are processed in the same facility in the same way, a lot of those variables are controlled, but nonetheless, they had different aromas. What strain did you look at? How was the aroma different from one phenotype to the other? And then what did you actually find in terms of the chemistry there.
Iain Oswald 52:47
So we looked at Starburst 36, from 710, labs and TierPoint process the same all the same conditions for growing so those variables were taken care of. And really, what we're interested in looking at was the rosin samples, these helped us see really low concentration compounds that would be otherwise difficult to detect, such as in flour. And what we ended up finding is that aromatically, there was definite partitioning between these phenotypes, which verified for us upfront that this process that breeders will go through fino hunting, has validity in the context of finding something that is truly unique. And then from there, we wanted to relate how do these aromatic qualities that our sensory team is picking up on relate to the chemistry?
Nick Jikomes 53:36
And so what did you find in terms of the chemistry? How did these phenotypes different from one another, and how much of that was the terpenes? How much of it was something else?
Iain Oswald 53:47
So the first class we looked at, like every good scientist in cannabis would do, where the terpenes. And what we found just like in our previous study, and 2020 theory, that a lot of these varieties will in this case phenotype. So again, genetically similar cannabis have very, very similar terpene profiles. In this case, we had a carry awful enrich profile for every single one. On the other hand, what we found is there were distinct differences in these new class of compounds that we refer to as flavorings, which in capital encapsulates, essentially any other compounds that are not terpenoid terpenes, that don't come from that sort of biosynthetic pathway.
Nick Jikomes 54:28
So they have different aromas, even though they have a similar terpene profile. And they're genetically similar, because these are all different phenotypes of the same strain. So how did you solve the mystery here? What was accounting for the difference in aroma?
Iain Oswald 54:41
So the first thing that we noticed in the sensory data was that a good two of the varieties ended up having an over representation of the aromatic notes that were considered citrus tropical, very heavy, heavy, kind of sweet, exotic or fruity, exotic sort. have notes, the other ones were ranked much lower. And so our previous work had shown that those citrus notes actually don't come from limonene, which a lot of people might suspect, but they come from a new class of volatile sulfur compounds that we refer to as Tropicana sulfur compounds, because they have these tropical nuances. And so they're in very low concentration. But they can still come through very, very potently. And what we found is, in one cluster, essentially two of the five phenotypes we measured, they were in much higher concentration, which correlated with the aroma data that we had, that showed that they had these tenacious citrus and sort of tropical robots. And
Nick Jikomes 55:43
so if the aromas not coming from the terpenes, what are these findings mean for consumers and people in the industry that are often thinking about the aroma, and the categorization of cannabis cannabis products through the lens of terpene profiles.
Iain Oswald 55:58
What it really means for end consumers in particular is that these terpene profiles can actually be deceiving. If you're looking for a specific, aromatic quality, because you're only capturing 50%, maybe even less than that have the true character of a specific variety, you can have a variety that has high limonene. But it has some other compound that makes it smell savory, and so it won't have any of those sort of tropical or citrus nuances, and vice versa. So I think for consumers, it's important to understand that terpenes are not the end all be all when it comes to the aroma of cannabis.
Nick Jikomes 56:34
And so what do you think is next in terms of unraveling the the chemical personality of strains and communicating that information to to a broader audience.
Iain Oswald 56:47
So the first thing would be simplifying these methodologies that we use in our lab to get them into the hands of analytical testing labs. So then they can adopt some of the methods we've done to report the sorts of numbers to consumers. And what we're also doing in that regard is decomposing this complex mixture of stuff into specific sort of metrics. And so we might have a metric that's like a sweet metric, you might have a gas metric, or a savory metric. And the point being is that because we know of the chemistry now, we can create standardized sort of numerical systems that will help guide people on a much deeper level than we do now.
Nick Jikomes 57:28
All right, well, Dr. Ian Boswell, thank you for sharing your research and I look forward to learning more as you guys publish even even more. Cool,
Iain Oswald 57:35
thank you Nick. Thanks for your time.
Plant Chemistry & the Chemical Basis of Marijuana Aroma | Iain Oswald | #167