Grapefruit mercaptan

Grapefruit mercaptan
Grapefruit mercaptan
Grapefruit mercaptan
Grapefruit mercaptan
Grapefruit mercaptan
Names
Preferred IUPAC name
2-[(1R)-4-Methylcyclohex-3-en-1-yl]propane-2-thiol
Other names
grapefruit mercaptan
1-p-menthene-8-thiol
α,α,4-trimethylcyclohex-3-ene-1-methane thiol
thioterpineol
Identifiers
CAS Number
  • 71159-90-5 (racemate) checkY
  • 83150-78-1 (R enantiomer) ☒N
3D model (JSmol)
  • Interactive image
ChemSpider
  • 21163535 checkY
ECHA InfoCard 100.072.886 Edit this at Wikidata
EC Number
  • 275-223-1
PubChem CID
  • 6427135
UNII
  • 7AT54D0N8R checkY
CompTox Dashboard (EPA)
  • DTXSID00894921 Edit this at Wikidata
InChI
  • InChI=1S/C10H18S/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3/t9-/m0/s1 ☒N
    Key: ZQPCOAKGRYBBMR-VIFPVBQESA-N ☒N
  • InChI=1/C10H18S/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3/t9-/m0/s1
    Key: ZQPCOAKGRYBBMR-VIFPVBQEBF
  • SC(C)(C)[C@@H]1CCC(C)=CC1
Properties
Chemical formula
 C10H18S
Molar mass 170.31 g/mol
Density 1.03 g/cm3
Melting point < 25 °C (77 °F; 298 K)
Boiling point 58 °C (136 °F; 331 K) at .33 mmHg
Hazards
GHS labelling:
Pictograms
 GHS07: Exclamation mark
Warning
Hazard statements
 H302, H315, H319
Precautionary statements
 P264, P270, P280, P301+P312, P302+P352, P305+P351+P338, P321, P330, P332+P313, P337+P313, P362, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Chemical compound

Grapefruit mercaptan is a natural organic compound found in grapefruit. It is a monoterpenoid that contains a thiol (also known as a mercaptan) functional group. Structurally a hydroxy group of terpineol is replaced by the thiol in grapefruit mercaptan, so it also called thioterpineol. Volatile thiols typically have very strong, often unpleasant odors that can be detected by humans in very low concentrations. Grapefruit mercaptan has a very potent, but not unpleasant, odor, and it is the chemical constituent primarily responsible for the aroma of grapefruit.[1] This characteristic aroma is a property of only the R enantiomer.[2]

Pure grapefruit mercaptan, or citrus-derived oils rich in grapefruit mercaptan, are sometimes used in perfumery and the flavor industry to impart citrus aromas and flavors. However, both industries actively seek substitutes for grapefruit mercaptans for use as a grapefruit flavorant, since its decomposition products are often highly disagreeable to the human sense of smell.

The detection threshold for the (+)-(R) enantiomer of grapefruit mercaptan is 2×10−5 ppb, or equivalently a concentration of 2×10−14. This corresponds to being able to detect 2×10−5 mg in one metric ton of water - one of the lowest detection thresholds ever recorded for a naturally occurring compound.[3]

See also

References

  1. ^ Buettner A.; Schieberle P. (1999). "Characterization of the Most Odor-Active Volatiles in Fresh, Hand-Squeezed Juice of Grapefruit (Citrus paradisi Macfayden)". J. Agric. Food Chem. 47 (12): 5189–5193. doi:10.1021/jf990071l. PMID 10606593.
  2. ^ Lehmann D.; Dietrich A.; Hener U.; Mosandl A. (1994). "Stereoisomeric flavor compounds. LXX: 1-p-menthene-8-thiol: separation and sensory evaluation of the enantiomers by enantioselective gas chromatography-olfactometry". Phytochemical Analysis. 6 (5): 255–257. doi:10.1002/pca.2800060506.
  3. ^ Demole, E.; Enggist, P.; Ohloff, G. (1982). "1-p-Menthene-8-thiol: A powerful flavor impact constituent of grapefruit juice (Citrus parodisi MACFAYDEN)". Helvetica Chimica Acta. 65 (6): 1785–1794. doi:10.1002/hlca.19820650614.