Geosmin

Geosmin
Geosmin
Names
Preferred IUPAC name
(4S,4aS,8aR)-4,8a-Dimethyloctahydronaphthalen-4a(2H)-ol
Other names
(4S,4aS,8aR)-4,8a-Dimethyl-1,2,3,4,5,6,7,8-octahydronaphthalen-4a-ol; 4,8a-Dimethyl-decahydronaphthalen-4a-ol; Octahydro-4,8a-dimethyl-4a(2H)-naphthalenol
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.039.294 Edit this at Wikidata
UNII
  • InChI=1S/C12H22O/c1-10-6-5-8-11(2)7-3-4-9-12(10,11)13/h10,13H,3-9H2,1-2H3/t10-,11+,12-/m0/s1 checkY
    Key: JLPUXFOGCDVKGO-TUAOUCFPSA-N checkY
  • InChI=1/C12H22O/c1-10-6-5-8-11(2)7-3-4-9-12(10,11)13/h10,13H,3-9H2,1-2H3 /t10-,11+,12-/m0/s1
  • O[C@]12[C@H](CCC[C@]2(CCCC1)C)C
Properties
C12H22O
Molar mass 182.307 g·mol−1
Melting point 78 to 82 °C (172 to 180 °F; 351 to 355 K)
Boiling point 270 to 271 °C (518 to 520 °F; 543 to 544 K)
Hazards
Flash point 104 °C (219 °F; 377 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Geosmin (/iˈɒzmɪn/ jee-OZ-min) is an irregular sesquiterpenoid, produced from the universal sesquiterpene precursor farnesyl pyrophosphate (also known as farnesyl diphosphate), in a two-step Mg2+-dependent reaction.[1] Geosmin, along with the irregular monoterpene 2-methylisoborneol, together account for the majority of biologically-caused taste and odor outbreaks in drinking water worldwide.[2] Geosmin has a distinct earthy or musty odor, which most people can easily smell. The geosmin odor detection threshold in humans is very low, ranging from 0.006 to 0.01 micrograms per liter in water.[2] Geosmin is also responsible for the earthy taste of beetroots and a contributor to the strong scent, known as petrichor, that occurs in the air when rain falls after a spell of dry weather or when soil is disturbed.[3]

In chemical terms, geosmin is a bicyclic alcohol with formula C12H22O, a derivative of decalin. Its name is derived from the Ancient Greek words geō- (γεω-), meaning "earth", and osmḗ (ὀσμή), meaning "smell". The word was coined in 1965 by the American biochemist Nancy N. Gerber (1929–1985) and the French-American biologist Hubert A. Lechevalier (1926–2015).[4][5]

  1. ^ Watson, W.; Juttner, F. (2019). Taste and Odour in Source and Drinking Water: Causes, Controls, and Consequences. IWA Publishing. ISBN 9781780406657.
  2. ^ a b Jüttner, Friedrich; Watson, Susan B. (July 2007). "Biochemical and Ecological Control of Geosmin and 2-methylisoborneol in Source Waters". Applied and Environmental Microbiology. 73 (14): 4395–4706. Bibcode:2007ApEnM..73.4395J. doi:10.1128/AEM.02250-06. PMC 1932821. PMID 17400777. S2CID 1954489.
  3. ^ "The earth's perfume". Protein Spotlight (35). June 2003.
  4. ^ Cite error: The named reference Gerber was invoked but never defined (see the help page).
  5. ^ "geosmin". Merriam-Webster Dictionary. 22 May 2023.