The natural woody component
Made from perfectly natural scrap
Gave an unearthly but natural smell
And naturally got the synthetic rap
I love Akigalawood® on salad and eggs. I think I love it in WINE most of all. But once I realized that rotundone is the geosmin of woody fruits and berries, I have no faith that all these beautiful peppery red wines I love didn’t get a little “shake, shake, shake” by some “Winestein” who figured out how to turn every average wine into a contender.
I am slowly learning not to care. Humans are natural. And they leave an incredible scent trail wherever they go. Sit back and enjoy the ride.
So by now you’re curious – hopefully.
I got curious about Akigalawood® from the moment I read the name, but I didn’t get curious enough to dig for the “molecular truth” until I wore L’Homme Lacoste and read that it contained that “mysterious” component.
Akigalawood® did NOT take the perfume world by storm – but it has been steadily appearing in more and more perfumes since roughly 2015.
In doing so, Akigalawood® has been accused by perfumistas, as one might expect, of being the “next norlimbanol”. But when it was finally accused of actually BEING norlimbanol, I decided that I had to find out if it was true.
And it may actually be true, in a way, but it’s complicated. Because “akigalawood” the smelled and labeled note is not the same thing as Akigalawood® the captive.
Let me explain that.
One of my favorite accords – “guaiac wood” – which was identified by a combination of sniffing, reading, and basic logic, for numerous perfumes – turns out to actually be a combination of guaiac wood oil and norlimbanol. It might as well be called “impression of guaiac wood” or something like that.
I don’t remember who clued me in on this, or which fragrance we were discussing, but it explained why the accord smells both different from and better than pure guaiac wood “oil” (a wax at room temperature), which I had bought for both comparison and home experimentation.
Are you starting to see why they use norlimbanol?
I remember the first time I smelled somebody’s pure norlimbanol at WPC 2012. The stuff smelled “woody”, but quite far from any kind of actual “wood” I was recognizing in fragrance.
Nor did it smell – to me – like it did to Chandler Burr.
Norlimbanol is one of the most amazing scents around, a genius molecule that should be worth its weight in gold; Norlimbanol gives you, quite simply, the smell of extreme dryness, absolute desiccation, and if you smell it, you’ll understand that instantly—the molecule is, by itself, a multi-sensory Disney ride.Chandler Burr
To me, norlimbanol smelled like some kind of wood putty. Not dry – not wet – not even like wood. It almost smelled like something one might apply to wood. An oil. A putty. A preservative.
But to the perfumer’s nose, there must have been quite a bit of possibility. I remember standing next to several entranced perfumers, sniffing the same thing on their own moillettes, and they were mesmerized – literally zoned out.
So, it may very well be that what most of us are smelling as akigalawood, the note, actually DOES contain norlimbanol – along with Akigalawood®, the Givaudan captive component.
Fair enough. But what’s in the captive that is actually for sale?
For one thing (it’s a mixture), it contains THE SPICE.
The “spice” of wood, spices, pepper, wine, patchouli, and many other things.
This is rotundone – a very powerful and important natural scent molecule that imparts a beautiful peppery note to damn near everything, including red wine, and both white and black pepper.
I also strongly suspect that this stuff is in aged, old, oxidized patchouli oil, which has one of the most magical smells of anything I own.
Yes – you read that correctly. “Akigalawood” is related to “agarwood”. Presumably it is responsible for the peppery aspects of a good oud.
Fascinatingly, rotundone is what gives peppery aspects to certain wines. The paper where this was discovered in 2012 is an excellent place to find out more about rotundone in wine, but if you do a web search, you will find even more, because the “winiacs” have been all over the topic.
But for me, the kicker is that this substance is the finishing touch on both white and black pepper. I am an absolute pepper fiend – I cannot get enough of the stuff. At the border between wood and spice – whether that be freshly, coarsely ground black pepper on a salad – running some reddish oak boards through a saw – or a beautiful fragrance like Poivre Samarcande by Hermès – I am in one of my greatest magic moments with any kind of really woody pepper or peppery wood.
“A massive, beautiful oak tree once grew in front of my house, blocking our view of the Mediterranean. Eventually, it grew ill and was felled. The peppery, musky, slightly smoky scent of cut wood etched itself on my memory. The soul of the old oak, mixed with pepper, lives on in this fragrance. The name Samarcande is a homage to the city through which spice caravans once passed on their way from East to West.”Jean-Claude Ellena
Of course, one cannot read Ellena’s description of his olfactory inspiration for Poivre Samarcande, and not see the parallel of that diseased old oak to the origin of agarwood.
Now – this is precisely the point where most people are reminded of natural processes, and the contrast of those complex aromas with (more or less) unimolecular scents – such as the one made famous by Jean-Claude Ellena, in both Poivre Samarcande and Terre d’Hermès – specifically, Iso E Super®.
Whether or not Iso E Super® is ever found naturally, consider two similar molecules that are – ambroxan and now rotundone.
“Yeah, so you’re talking about some synthetically made natural component. Those all smell very unnatural because they’re just one molecule.”
I hope that you are now seeing the downside of radical abundance. We have figured out the key odorants of great “natural smells”, and yet these natural molecules, in isolation, can smell decidedly unnatural.
Or take norlimbanol, which many regard as very synthetic, like Iso E Super®.
These are two mirror image isomers (“enantiomers”) of norlimbanol. Now compare it to ambroxan.
It helps to have a bit of organic chemistry to see this, but if you take that ambroxan molecule and make three snips of bonds in the exact right places, breaking two rings and lopping off that “CH3” (methyl group) on the right, while flipping UP the CH3 at the bottom when you snip the ring to its right, you get one of the norlimbanol isomers.
In other words, the norlimbanol molecule is deeply related to the natural product ambroxan, which powers ambergris.
It’s kinda cool, but our very natural sense of smell dictates that even the synthetic smells we like, tend to be structurally very similar to natural smells we like, for the vast majority of odorants. Nitro compounds seem to be a fun exception.
But back to Akigalawood®, the captive. This is actually a more “natural” substance than you may think.
The name “Akigalawood” was trademarked by Givaudan on May 28, 2012, and the trademark expires on that date in 2022.
Fragrantica describes it thusly:
Odor profile: A synthetic molecule reminiscent of patchouli with a hint of pepper and fine agarwood.https://www.fragrantica.com/notes/Akigalawood-697.html
That odor profile turns out to be fairly complete description.
Parfumo describes it this way:
Akigalawood is a perfume note which was fractionated from patchouli oil and is used by Givaudan. Its odor is described as woody, spicy and floral.https://www.parfumo.net/Fragrance_Note/Akigalawood
The manufacturer, Givaudan, describes it this way:
“The mission of the Ingredients Centre of Excellence in Zurich, Switzerland is to employ enzymes to develop new fragrance ingredients, and it was within this context that the Biosciences team recently created Akigalawood®, where an enzyme known as laccase was used to transform a natural starting material into a new natural and captive perfume compound. Akigalawood® has recently been commercialised in a leading men’s fragrance for the Brazilian market. This novel material has a profile similar to that of patchouli, combined with vibrant spicy aspects of pepper and noble agarwood facets. This enzymatic process, which only requires mild processing with salt and water, is also a far more environmentally friendly way to develop new raw materials for fragrance use.”https://www.givaudan.com/sustainability/can-face-cream-save-planet
This same page goes on to describe the manufacture.
This first success originates from a new approach that Boris and his team initiated, where enzymes are used to transform leftover residues and easily accessible natural feedstocks into valuable perfumery ingredients.” Boris states why Akigalawood® has such a successful and innovative profile: “Akigalawood®, which is now a Givaudan registered trademark, represents an exciting new addition to our perfumers’ palettes, in particular because it consists of various powerful and elegant molecules that are otherwise not accessible to the perfumers. Creating new ingredients through bioscience approaches is an excellent expansion to traditional chemistry and also has environmental benefits whenever we manage to make use of a former ‘waste’ product within our supply chain.”https://www.givaudan.com/sustainability/can-face-cream-save-planet
Based on all this information, and combining it in the most logical fashion, some form of patchouli waste stream or less useful patchouli oil fraction is being treated with the enzyme laccase.
Searching the web on patchouli and laccase, and looking for images, we find this reaction diagram:
Following this image to its source yields a description of exactly what we are looking for – treatment of a patchouli fraction with laccase.
The use of enzymes in organic synthesis and the life sciences: perspectives from the Swiss Industrial Biocatalysis Consortium (SIBC)
Hans-Peter Meyer*a, Eric Eichhornb, Steven Hanlonc, Stephan Lützd, Martin Schürmanne, Roland Wohlgemuthf and Raffaella Coppolecchiag
bGivaudan Schweiz AG, Ueberlandstrasse 138, 8600 Dübendorf, Switzerland
(plus additional authors)
Section 3.1 of the paper starts off with the Givaudan work. The reaction scheme cited above has this caption:
Fig. 1 Oxidation of an α-guaiene rich olefinic fraction with a laccase-mediator system. The olefinic fraction is treated with the Denilite® II S laccase (Novozymes) resulting in the oxidation of oil-resident olefins to the corresponding alcohols, ketones or epoxide.
Reference 11 takes us to a World Patent Application:
WO2012001018 – 1-HYDROXY-OCTAHYDROAZULENES AS FRAGRANCES
This is exactly what we want.
These are the desired products:
These are the preferred starting materials:
Alpha guaiene is the key starting material that leads to rotundone.
A description of the preferred patchouli fraction is provided:
Instead of using patchouli oil as a starting material one may use a light fraction of patchouli oil. By “light fraction of patchouli oil” is meant in the present context the volatile fraction obtained by distillation of patchouli oil that contains the sesquiterpenic olefins of the oil. In one embodiment the light fraction is enriched in a-guaiene and/or a-bulnesene. In another embodiment the light fraction of the patchouli oil is essentially free of patchouli alcohol (CAS 5986-55-0). By “essentially free” is meant a patchouli oil fraction comprising less than 2% patchouli alcohol, preferably less than 1% by weight based on the used fraction.
The fraction of patchouli oil essentially free of patchouli alcohol is preferably used because patchouli alcohol is of high perfumery interest when taken alone.
To be of commercial interest for the production of compounds of formula (I) as defined above the patchouli oil comprises at least 0.05 weight % (e.g. at least 0.1 to about 1 weight %) of a-guaiene and/or α-bulnesene based on the used fraction. Preferably, at least one of the two compounds is present in amounts up to about 50 weight % or even higher, e.g. the patchouli oil or a light fraction thereof comprises about 15 – 70% by weight of α-bulnesene based on the used fraction, or e.g. the patchouli oil or a light fraction thereof comprises about 15 – 50% by weight of α-guaiene based on the used fraction.Description of starting patchouli fraction
Several examples of the preparation of the invention mixture are given – this is probably the best and most typical.
Example 3: mixture of (1R,3S,5R,8S)- / (1 S,3S,5R8S)-3,8-dimethyl-5-(prop-1-en-2-yl)-1 ,2,3,4,5,6,7,8-octahydroazulen-1 -ol and rotundone from an olefinic mixture containing a-guaiene
Composition (%w/w) of the starting olefinic mixture according to GC-MS analysis : δ- elemene (0.3), β-patchoulene (5.6), β-elemene (3), cycloseychellene (1.75), β-caryophyllene (7), α-guaiene (27), a-patchoulene (10), seychellene (14), δ-patchoulene (5.5), γ-patchoulene (0.45), α-humulene (1), aciphyllene (4), α-bulnesene (18).
A mixture of alpha-guaiene rich olefinic fraction (200 g), 1M KH2PO4/K2HPO4 pH 7.5 buffer solution (200 ml), DeniLite® II S laccase (20 g; from Novozymes), and water (1600 ml) was stirred vigorously while a slow flow of air was bubbled through the sintered glass end of a gas introduction tube, and heated at 40°C for 46 hours. Air-bubbling was stopped and NaOH (20 g, 0.5 mol) was added into the mixture that was heated to reflux under vigorous stirring and N2-bubbling for 9.5 h while the colour of the mixture turned from yellow to brown The resulting mixture was cooled to 25°, poured into H2O (750 ml), and extracted twice with MTBE (750 and 350 ml). The joined organic phases were washed twice with H2O (250 ml) and once with aqueous saturated NaCl solution (250 ml), and dried with MgSO4. Filtration and evaporation of the solvent led to 188 g of crude material. Short-path distillation led to 55.5 g (28 % yield based on 200 g olefinic mixture) of olfactorily pure material (fractions 8-15, 104-153°C/0.10 mbar, oil bath temperature 125-175°C).
GC-analysis: 7.0% caryophyllene oxide, 2.9% (1R,3S,5R ,8S)-3,8-dimethyl-5-(prop-1-en-2-yl)-1, 2,3,4,5,6, 7,8-octahydroazulen-1-ol, 3.1% (1 S,3S,5R,8S)-epimer, 4.2% β-patchoulenone, 7.2% rotundone, 0.3% α-bulnesenone, 0.5% (1R ,3S,3aS,5R)-3,8-dimethyl-5-(prop-1-en-2-yl)-1 ,2,3,3a,4,5,6,7-octahydroazulen-1-ol (compound of formula I), 0.9% (1 S,3S,3aS,5R)-3,8-dimethyl-5-(prop-1-en-2-yl)-1 ,2,3,3a,4,5,6,7-octahydroazulen-1-ol (compound of formula I).
Odour description of the mixture (fraction 8-15): woody, floral, tobacco, reminiscent of some aspects of patchouli and pepper.Example 3 – Laccase oxidation of a light patchouli olefin fraction
The product of example 3 was then used in a fragrance composition at a rate of 60/900, giving this result.
The addition of the mixture obtained according to the procedure described in Example 3 imparts to the perfume composition, on the one hand a woody, balsamic, peppery note reminding of some cedar aspects of patchouli and of some tobacco-like aspects of agarwood and on the other hand a floral, rosy note reminding of dried leaves. Moreover, the addition of the mixture of Example 3 boosts the bergamot-coumarine accord thus enhancing the diffusion, volume and trail of the whole fragrance.Effect of adding the invention mixture (presumably Akigalawood or similar) to a perfume
Thus, I am fairly certain that Akigalawood® is a rotundone-containing mixture of reaction products as described in both the patent and the reaction diagram of the journal article.
Akigalawood® can thus be described as “a mixture of patchouli olefins oxidized to corresponding alcohols and ketones, including rotundone”.
These are either natural products, or a spitting distance away. And as a mixture, derived from a natural mixture, Akigalawood® has all the advantages of a natural mixture, in terms of smelling “natural” due to complexity.
Thus, it is no surprise that Akigalawood® has been described as woody, peppery, and patchouli-like.
As a lover of patchouli, I’m happy that Givaudan made this stuff, and I hope this starts a trend, leading back to more “natural-smelling” fragrances.
Not so much for myself, but for my fellow perfumistae who are put off by “synthetic” smells.
A toast to Givaudan, for “taking out the trash”, and turning it into beautiful fragrance!
Errrrr, I mean – ROTUNDONE!