Material guide: dihydro-beta-ionone — the odour field says woody, amber, cedar, and it lasts nine hours

CAS 17283-81-7. Thirty suppliers. The odour field lists fourteen descriptors including woody, mahogany, amber and cedar, which sounds entirely like a base material. Its substantivity is 9 hours at 100%, ranking 181st shortest among the 800 materials with 20+ suppliers and a substantivity record. Someone put it at 8% of their first perfume as a woody backbone, which will not go as planned. And the database's occurrence field misses an important source: a 2022 paper opens by calling it a characteristic aroma compound of Osmanthus fragrans, and osmanthus is not in that field.

Two fields side by side.

Odour field:

earthy, woody, mahogany, orris, dry, amber, cedar, berry, seedy, oily, raspberry, floral, tea, leafy

Substantivity field:

9 hours at 100%

Four of those fourteen descriptors read like a base note, and it lasts nine hours.

The short version

CAS 17283-81-7, C₁₃H₂₂O, MW 194.32, 30 suppliers.
Substantivity 9 hours at 100%. Counting the 800 database materials with 20+ suppliers and a substantivity record, it ranks 181st shortest — inside the shortest quarter.
It appears in 23 corpus formulas across two spellings, at median doses of 1.50% and 5.31%.
Someone put it at 8% of their first perfume as part of a woody backbone. A nine-hour material will not hold a backbone.
The database's occurrence field misses an important source. It lists boronia absolute, champaca absolute, peach, raspberry, rose and violet — and a 2022 paper opens with: dihydro-β-ionone is a characteristic aroma compound of Osmanthus fragrans.
Its chemical origin is clean: cleave a carotenoid, then reduce a double bond. A 2003 study had two microbes divide those two steps between them; a 2022 study did both with purified enzymes in one pot.
GHS carries H401/H411, toxic to aquatic life. The same grade as alpha-amyl cinnamaldehyde.

About 8 minutes.

What nine hours means

This is the first thing to know about the material.

Material	Substantivity
Calone	> 600 hours at 10% dilution
isoeugenol	400 hours at 100%
alpha-irone	104 hours at 100%
para-anisaldehyde	44 hours at 100%
dihydro-β-ionone	9 hours at 100%
dimethyl sulfide	4 hours at 100%

It sits closer to dimethyl sulfide than to irone.

And β-ionone itself reads 112 hours. Same skeleton, one double bond reduced, and a twelvefold difference in substantivity.

(Read that table carefully: these figures come from inconsistent measurement conditions, some neat and some diluted. The 9 and the 112 are both at 100%, so that pair is comparable.)

The practical upshot is direct: this is not a base material, however its odour field reads.

Someone put it at 8% of their first perfume — the fourth largest component of their formula, presumably as woody support. The corpus median is 1.50%.

It behaves more like an opening woody: mahogany and dry wood for the first hour or two, then a handover. If you want wood that stays, something else has to carry it.

Fourteen descriptors

The material's second peculiarity is an absurdly long odour field.

earthy, woody, mahogany, orris, dry, amber, cedar, berry, seedy, oily, raspberry, floral, tea, leafy

Fourteen words spanning woody, fruity, floral, tea and earth.

This is not the database being lazy. The ionone family has this property: they are carotenoid degradation products, and carotenoids degrade in a great many fruits, flowers and tea leaves. So one molecule plausibly belongs in raspberry, peach, black tea and a woody accord alike.

The occurrence field supports it:

boronia absolute @ 1.30%, boronia flower, champaca absolute @ 1.40%, champaca concrete @ 0.30%, peach, plumcot, raspberry, Rosa hybrida, Viola odorata…

One molecule, showing up in flowers, fruit and tea.

The occurrence field misses osmanthus

This is the part of the piece worth remembering.

Qi and colleagues' 2022 paper in Bioprocess and Biosystems Engineering opens with this sentence:

Dihydro-β-ionone is a characteristic aroma compound of Osmanthus fragrans and is widely applied in the flavor & fragrance industry.

And osmanthus is not in the database's occurrence field.

That is a substantive gap rather than a wording issue. Osmanthus absolute is an important natural in perfumery, and someone searching for which naturals contain this molecule would miss the most relevant one.

We've written about database fields being wrong — veramoss's occurrence field says "not found in nature" when it is a lichen metabolite. This record's problem is different: not wrong, but incomplete.

The two failure modes need different defences. A wrong entry can be caught by cross-checking; an incomplete one is caught only if you happen to know what to look for.

The practical advice: after reading an occurrence field, search the literature by molecule name as well. The same conclusion as the para-anisaldehyde piece: searching only within perfumery misses half.

Where it comes from

This molecule's origin is clean, and two papers approached it from opposite directions.

The job has two steps:

Cleave a carotenoid to get β-ionone
Reduce β-ionone's double bond to get dihydro-β-ionone

2003: two microbes dividing the work.

Maldonado-Robledo and colleagues studied a mixed culture of Bacillus sp. and Geotrichum sp. in Applied Microbiology and Biotechnology, producing tobacco aroma compounds from the carotenoid lutein.

And they worked out who does what:

Both microorganisms can grow independently in a medium supplemented with lutein, but only Geotrichum produces β-ionone. This intermediate was incorporated by the bacilli, converted to aroma and this product excreted to the culture medium. … We conclude that, in the bioconversion of lutein to products with tobacco aroma, Geotrichum sp. is involved in carotenoid oxidation to produce β-ionone and Bacillus sp. is responsible for the norisoprenoid reduction to produce 7,8-dihydro-β-ionone and 7,8-dihydro-β-ionol.

One organism cuts, the other reduces.

2022: two enzymes in one vessel.

Qi and colleagues did the same two steps with purified enzymes: carotenoid cleavage dioxygenase PhCCD1 from Petunia hybrida for the first, enoate reductase AaDBR1 from Artemisia annua for the second.

They report PhCCD1's optimal activity at pH 6.8 and 45 °C, stability across pH 6.0-8.0 and good thermal stability below 40 °C. Adding an NADPH regeneration system gave a 1.5-fold improvement, yielding approximately 13.34 mg/L of dihydro-β-ionone at a molar conversion of 85.8%.

And the paper states the current situation:

However, the main focus is on chemical synthesis due to the metabolic pathways of dihydro-β-ionone is still unclear.

So what you buy is almost certainly synthetic, and those two papers are exploring another route.

13.34 mg/L is a very small number — a laboratory-scale in vitro system, not an industrial yield. The paper describes it as the first time such an in vitro pathway has been designed and built.

Physical properties

Property	Value
CAS	17283-81-7
Formula	C₁₃H₂₂O, MW 194.32
Appearance	colourless to pale yellow clear liquid (est)
Boiling point	261-262 °C
Flash point	> 100 °C
logP	2.70 (est)
Water solubility	48 mg/L at 20 °C (experimental)
Substantivity	9 hours at 100%
Strength	medium
Shelf life	24 months or longer
Suppliers	30
GHS	H315, H401 / H411 toxic to aquatic life

The GHS line deserves a pause. H411, toxic to aquatic life with long lasting effects, is the same grade as alpha-amyl cinnamaldehyde — and that piece showed how that grade drops IFRA's household limits by an order of magnitude.

A 24-month shelf life is longer than the aldehydes' 12. It is a ketone and more stable than an aldehyde.

What this doesn't establish

I have not smelled it. The whole piece sets database fields, the formula corpus and two papers against each other.

"9 hours" is a single database record, and substantivity measurement conditions are inconsistent across the database. I compare it only against other figures also marked at 100%.

"181st shortest" comes from ranking the 800 materials with 20+ suppliers and a substantivity record. A different filter gives a different rank.

"The occurrence field misses osmanthus" comes from setting the database field against Qi's opening sentence. That paper gives no content figure for osmanthus, so I do not know what share of osmanthus absolute it represents. All I can say is that the paper calls it a characteristic aroma compound and the field does not list it.

Maldonado-Robledo's product was "compounds with tobacco aroma", of which 7,8-dihydro-β-ionone is one. That is not a process aimed at producing this fragrance material, but a study of microbial division of labour.

Qi's 13.34 mg/L is the yield of an in vitro coupled reaction. It is a laboratory system, not an industrial figure, and the paper itself says chemical synthesis remains the main route.

The 23 corpus formulas combine two spellings (dihydro-beta-ionone and dihydro beta ionone). Their medians differ substantially (1.50% and 5.31%), both samples are small, and I did not pool them into one median.

I offer no verdict on that beginner's 8%. I note only that it sits far above the corpus median and that the material lasts nine hours. Whether the perfume smells good I cannot know.

The GHS classification is what the database records, not a complete regulatory determination. Work from the SDS for your own batch and the current IFRA standard.

References

Z. Qi, X. Tong, X. Zhang, H. Lin, S. Bu, L. Zhao, One-pot synthesis of dihydro-β-ionone from carotenoids using carotenoid cleavage dioxygenase and enoate reductase, Bioprocess and Biosystems Engineering, 45(5), 891-900 (2022). PMID 35244776. doi:10.1007/s00449-022-02707-x

G. Maldonado-Robledo, E. Rodriguez-Bustamante, A. Sanchez-Contreras, R. Rodriguez-Sanoja, S. Sanchez, Production of tobacco aroma from lutein. Specific role of the microorganisms involved in the process, Applied Microbiology and Biotechnology, 62(5-6), 484-488 (2003). PMID 12827317. doi:10.1007/s00253-003-1315-6