2-Methylisoborneol

2-Methylisoborneol (MIB) is an irregular monoterpene derived from the universal monoterpene precursor geranyl pyrophosphate. MIB and the irregular sesquiterpene geosmin together account for the majority of biologically-caused taste and odor outbreaks in drinking water worldwide.^[1] MIB has a distinct earthy or musty odor, which most people can easily smell. The odor detection threshold of MIB is very low, ranging from 0.002 to 0.02 micrograms per liter in water.^[2] MIB is also a factor in cork taint in winemaking.

2-Methylisoborneol

Names
IUPAC name 1,2,7,7-tetramethylbicyclo[2.2.1]heptan-2-ol
Other names 2-Methyl-2-bornanol
Identifiers
CAS Number	2371-42-8^N
3D model (JSmol)	Interactive image Interactive image
Abbreviations	MIB
ChEBI	CHEBI:61987
ChemSpider	16024^Y
KEGG	C20243
PubChem CID	16913
CompTox Dashboard (EPA)	DTXSID90940148
InChI InChI=1S/C11H20O/c1-9(2)8-5-6-10(9,3)11(4,12)7-8/h8,12H,5-7H2,1-4H3^Y Key: LFYXNXGVLGKVCJ-UHFFFAOYSA-N^Y InChI=1/C11H20O/c1-9(2)8-5-6-10(9,3)11(4,12)7-8/h8,12H,5-7H2,1-4H3 Key: LFYXNXGVLGKVCJ-UHFFFAOYAW
SMILES CC1(C2CCC1(C(C2)(C)O)C)C OC2(C)CC1CCC2(C1(C)C)C
Properties
Chemical formula	C11H20O
Molar mass	168.28 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references

MIB is produced by various blue-green algae (cyanobacteria) and filamentous bacteria in the class Actinomycetia, and also some other prokaryotes and eukaryotes. The main genera in the cyanobacteria that have been shown to produce MIB include Oscillatoria, Phormidium, and Planktothrix, while the main genus in the Actinomycetia that produces MIB is Streptomyces.^[3][4] They give a musty or earthy odor that can be quite strong if an algal bloom is present. Subsequent death of the microorganisms will release MIB that is trapped in the cells. Along with geosmin, the off flavors that result are issues in the seafood industry. This chemical is the major cause of "muddy" or "dirt" flavors in catfish and crawfish.^[5]

Rhodococcus and Comamonas bacteria can degrade 2-methylisoborneol.^[6]

References

1. Jüttner, Friedrich; Watson, Susan B. (2007). "Biochemical and Ecological Control of Geosmin and 2-Methylisoborneol in Source Waters". Applied and Environmental Microbiology. 73 (14): 4395–4406. Bibcode:2007ApEnM..73.4395J. doi:10.1128/aem.02250-06. PMC 1932821. PMID 17400777.
2. Lin, Tsair-Fuh; Watson, Susan; Dietrich, Andrea M.; (Mel) Suffet, I. H. (15 March 2018). Taste and Odour in Source and Drinking Water: Causes, Controls, and Consequences. IWA. ISBN 978-1-78040-665-7.
3. Juttner, F.; Watson, S. (2007). "Biochemical and Ecological Control of Geosmin and 2-Methylisoborneol in Source Waters". Applied and Environmental Microbiology. 73 (14): 4395–4406. Bibcode:2007ApEnM..73.4395J. doi:10.1128/AEM.02250-06. PMC 1932821. PMID 17400777.
4. G. Izaguirre; W.D. Taylor (2004). "A Guide to Geosmin and MIB-producing Cyanobacteria in the United States". Water Science and Technology. 49 (9): 19–24. doi:10.2166/wst.2004.0524. PMID 15237602.
5. Lloyd, Steven W; Grimm, Casey C (1999). "Analysis of 2-Methylisoborneol and Geosmin in Catfish by Microwave Distillation−Solid-Phase Microextraction". Journal of Agricultural and Food Chemistry. 47 (1): 164–169. doi:10.1021/jf980419x. PMID 10563866.
6. Guttman, Lior; van Rijn, Jaap (15 January 2012). "Isolation of Bacteria Capable of Growth with 2-Methylisoborneol and Geosmin as the Sole Carbon and Energy Sources". Applied and Environmental Microbiology. 78 (2): 363–370. Bibcode:2012ApEnM..78..363G. doi:10.1128/AEM.06333-11. PMC 3255726. PMID 22081577.