Citral

Citral
IUPAC name	3,7-dimethyl-2,6-octadienal
Other names	citral geranial neral geranialdehyde
Identifiers
CAS number	5392-40-5
RTECS number	RG5075000
SMILES	O=CC=C(C)CCC=C(C)C
Properties
Molecular formula	C10H16O
Molar mass	152.24 g/mol
Appearance	Pale yellow liquid
Odor	Lemon like
Density	0.893 g/cm³, liquid
Boiling point	229 °C
Hazards
NFPA 704	1 0 0
R-phrases	R36, R37, R38
Flash point	91 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references

Citral, or 3,7-dimethyl-2,6-octadienal or lemonal, is either of a pair of terpenoids with the molecular formula C₁₀H₁₆O. The two compounds are double bond isomers. The E-isomer is known as geranial or citral A. The Z-isomer is known as neral or citral B.

Geranial has a strong lemon odor. Neral has a lemon odor that is less intense, but sweeter. Citral is therefore an aroma compound used in perfumery for its citrus effect. Citral is also used as a flavor and for fortifying lemon oil. It also has strong anti-microbial qualities^[1], and pheromonal effects in insects.^[2][3]

Citral is used in the synthesis of vitamin A, ionone, and methylionone, and to mask the smell of smoke.

Citral is present in the oils of several plants, including lemon myrtle (90-98%), Listsea citrata (90%), Litsea cubeba (70-85%), lemongrass (65-85%), lemon tea-tree (70-80%), Ocimum gratissimum (66.5%), Lindera citriodora (approx. 65%), Calypranthes parriculata (approx. 62%), petitgrain (36%), Lemon verbena (30-35%), Lemon ironbark (26%), lemon balm (11%), lime (6-9%), lemon (2-5%), and orange.^{[4] [5] [6]}

[edit] Health and safety information

Citral should be avoided by people with perfume allergy.^[7]

[edit] See also

• Citronellal
• Geraniol
• Nerol

[edit] References

[edit] Footnotes

1. ^ Onawunmi, G.O. (1989) Evaluation of the antimicrobial activity of citral. Lett. Appl. Microbial. 9, 105-108.
2. ^ Kuwahara, Y., Suzuki, H., Matsumoto, K. & Wada, Y. (1983) Pheromone study on acarid mites. XI. Function of mite body as geometrical isomerization and reduction of citral (the alarm pheromone) Carpoglyphus lactis. Appl. Entomol. Zool. 18, 30-39.
3. ^ Robacker, D.C. & Hendry, L.B. (1977) Neral and geranial: components of the sex pheromone of the parasitic wasp, Itoplectis conquisitor, J. Chem. Ecol. 3, 563-577.
4. ^ Fenaroli, G., Furia, T.E., Bellanca, N., Handbook of Flavor Ingredients, ISBN 0878195327
5. ^ Lawless, J., The Illustrated Encyclopedia of Essential Oils, ISBN 1-85230-661-0
6. ^ The Aromatic Plant Project [1]
7. ^ Survey and health assessment of chemical substances in massage oils

[edit] General references

• MSDS [2]

[edit] External links