April 24, 2023
I’m a sweet-smelling, natural-born killer.
What molecule am I?
Image of 3-Octanone 3D Image of 3-Octanone

3-Octanone, known to old-timers as n-amyl ethyl ketone, is a fragrant liquid produced by plants as diverse as lavender (Lavandula angustifolia), rosemary (Salvia rosmarinus), and nectarines (Prunus persica var. nucipersica). Its olfactory properties make it a useful flavor and fragrance agent.

But 3-octanone has a malicious side. A widely cultivated and consumed mushroom, Pleurotus ostreatus, produces the ketone to combat nematode (Caenorhabditis elegans) invasions. This distinct strategy kills the microscopic worms by disrupting their cell membranes and then uses them as nutrients.

In January this year, Yen-Ping Hsueh and several colleagues at Academica Sinica (Taipei, Taiwan), National Taiwan University (Taipei), and other institutions in Taiwan and Japan demonstrated the mechanism that 3-octanone uses against the mushroom’s prey. When the researchers treated C. elegans directly with the ketone, it caused the same rapid paralysis, calcium influx, and neuronal cell death as does the carnivorous mushroom.

3-Octanone hazard information

Hazard class*GHS code and hazard statement
Flammable liquids, category 3H226—Flammable liquid and vaporChemical Safety Warning
Skin corrosion/irritation, category 2H315—Causes skin irritationChemical Safety Warning
Serious eye damage/irritation, category 2AH319—Causes serious eye irritationChemical Safety Warning

*Globally Harmonized System (GHS) of Classification and Labeling of Chemicals. Explanation of pictograms.

MOTW updates

Fipronil1 was the Molecule of the Week for June 14, 2021. It is a broad-spectrum insecticide with several known environmental hazards, including contamination of chicken eggs in the Netherlands in 2017. Earlier this month, Weidong Qu and colleagues at Fudan University (Shanghai), the China National Center for Food Safety Risk Assessment (Beijing), Qingdao University (China), and Oxford University (UK) reported that fipronil and its metabolites in drinking water can produce thyroid-disrupting effects in humans.

Naloxone 2 (trade name Narcan) was the Molecule of the Week for May 23, 2016. It is an opiate antagonist first produced in the 1960s that is much in the news as a nasal-spray “rescue” drug for people who overdose on opioids. In late March, the US Food and Drug Administration approved naloxone for over-the-counter sales. Its manufacturer says that it should be available in stores and online by late summer.

1. CAS Reg. No. 120068-37-3.
2. CAS Reg. No. 465-65-6.

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3-Octanone fast facts

CAS Reg. No.106-68-3
SciFinder nomenclature3-Octanone
Empirical formulaC8H16O
Molar mass128.21 g/mol
AppearanceColorless, oily liquid
Boiling point168 °C
Water solubility2.6 g/L
Chemical Abstract Service - a division of ACS

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