Camphor

Camphor

Camphor[1][2]
Structural formula of camphor
Ball and stick model of camphor ((1R,4R)-1-methyl,heptan)
Names
IUPAC name
1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one
Systematic IUPAC name
1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one
Other names
2-Bornanone; Bornan-2-one; 2-Camphanone; Formosa
Identifiers
 Y
 N
(R) N
(S) N
3DMet
ATC code C01
1907611
ChEBI  Y
ChEMBL  N
ChemSpider  Y
(R) Y
(S) Y
DrugBank  Y
EC number 200-945-0
83275
Jmol-3D images Image
Image
KEGG  Y
MeSH
PubChem
 (R)
 (S)
RTECS number EX1225000
UNII  Y
UN number 2717
Properties
C10H16O
Molar mass 152.24 g·mol−1
Appearance White, translucent crystals
Odor fragrant and penetrating
Density 0.992 g cm−3
Melting point 175 to 177 °C (347 to 351 °F; 448 to 450 K)
Boiling point 209 °C (408 °F; 482 K)
1.2 g dm−3
Solubility in acetone ~2500 g dm−3
Solubility in acetic acid ~2000 g dm−3
Solubility in diethyl ether ~2000 g dm−3
Solubility in chloroform ~1000 g dm−3
Solubility in ethanol ~1000 g dm−3
log P 2.089
Vapor pressure 4 mmHg (at 70 °C)
Chiral rotation ([α]D)
+44.1°
Hazards
Highly Flammable FHarmful Xn
R-phrases R11 R22 R36/37/38
S-phrases S16 S26
NFPA 704
2
2
0
Flash point 54 °C (129 °F; 327 K)
466 °C (871 °F; 739 K)
Explosive limits 0.6%-3.5%[3]
Lethal dose or concentration (LD, LC):
LD50 (Median dose)
1310 mg/kg (oral, mouse)[4]
800 mg/kg (dog, oral)
2000 mg/kg (rabbit, oral)[4]
400 mg/m3 (mouse, 3 hr)[4]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 2 mg/m3[3]
REL (Recommended)
TWA 2 mg/m3[3]
200 mg/m3[3]
Related compounds
Related Ketones
Fenchone, Thujone
Related compounds
Camphene, Pinene, Borneol, Isoborneol, Camphorsulfonic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 N  (: Y/N?)

Camphor () is a waxy, flammable, white or transparent solid with a strong aromatic odor.[5] It is a terpenoid with the chemical formula C10H16O. It is found in the wood of the camphor laurel (Cinnamomum camphora), a large evergreen tree found in Asia (particularly in Sumatra, Indonesia and Borneo) and also of the unrelated kapur tree, a tall timber tree from the same region. It also occurs in some other related trees in the laurel family, notably Ocotea usambarensis. Dried rosemary leaves (Rosmarinus officinalis), in the mint family, contain up to 20% camphor. Camphor can also be synthetically produced from oil of turpentine. It is used for its scent, as an ingredient in cooking (mainly in India), as an embalming fluid, for medicinal purposes, and in religious ceremonies. A major source of camphor in Asia is camphor basil (the parent of African blue basil).

Norcamphor is a camphor derivative with the three methyl groups replaced by hydrogen.

Contents

  • Etymology 1
  • Production 2
  • Biosynthesis 3
  • Reactions 4
  • Uses 5
    • Explosives 5.1
    • Pest deterrent and preservative 5.2
    • Culinary 5.3
    • Medicinal 5.4
      • Regulation 5.4.1
    • Hindu religious ceremonies 5.5
  • See also 6
  • References 7
  • External links 8

Etymology

The word camphor derives from the French word camphre, itself from Medieval Latin camfora, from Arabic kafur, from Sanskrit, कर्पूरम् / karpūram.[6] The term ultimately was derived from Old Malay kapur barus which means "the chalk of Barus". Barus was the name of an ancient port located near modern Sibolga city on the western coast of Sumatra island (today North Sumatra Province, Indonesia).[7] This port was initially built prior to the Indian–Batak trade in camphor, benzoin and spices. Traders from India, East Asia and the Middle East would use the term kapur barus to buy the dried extracted ooze of camphor laurel trees (Cinnamonum camphora) from local Batak tribesmen; the camphor tree itself is endemic to that region. In the proto-Malay-Austronesian language, it is also known as kapur Barus. Even now, the local tribespeople and Indonesians in general refer to aromatic naphthalene balls and moth balls as kapur Barus.

Production

A sample of sublimed camphor

In the 19th century, it was known that nitric acid oxidizes camphor into urea) had been synthesized in the laboratory as a proof of concept, but camphor was a scarce natural product with a worldwide demand. Komppa realized this and began industrial production of camphor in Tainionkoski, Finland, in 1907.

Camphor can be produced from alpha-pinene, which is abundant in the oils of coniferous trees and can be distilled from turpentine produced as a side product of chemical pulping. With acetic acid as the solvent and with catalysis by a strong acid, alpha-pinene readily rearranges into camphene, which in turn undergoes Wagner-Meerwein rearrangement into the isobornyl cation, which is captured by acetate to give isobornyl acetate. Hydrolysis into isoborneol followed by oxidation gives racemic camphor. By contrast, camphor occurs naturally as D-camphor, the (R)-enantiomer.

Biosynthesis

In biosynthesis, camphor is produced from geranyl pyrophosphate, via cyclisation of linaloyl pyrophosphate to bornyl pyrophosphate, followed by hydrolysis to borneol and oxidation to camphor.

Biosynthesis of camphor from geranyl pyrophosphate

Reactions

Typical camphor reactions are

Camphor can also be reduced to isoborneol using sodium borohydride.

In 1998, K. Chakrabarti and coworkers from the Indian Association for the Cultivation of Science, Kolkata, prepared diamond thin film using camphor as the precursor for chemical vapor deposition.[8]

In 2007, carbon nanotubes were successfully synthesized using camphor in chemical vapor deposition process.[9]

Uses

The sublimating capability of camphor gives it several uses.

Explosives

Camphor is used as a plasticizer for nitrocellulose, an ingredient for fireworks and explosive munitions.

Pest deterrent and preservative

Camphor is believed to be toxic to insects and is thus sometimes used as a repellent.[10] Camphor is used to make mothballs. Camphor crystals are sometimes used to prevent damage to insect collections by other small insects. Some folk remedies state camphor will deter snakes and other reptiles due to its strong odor. It is kept in clothes used on special occasions and festivals, and also in cupboard corners as a cockroach repellent.

Camphor is also used as an antimicrobial substance. In embalming, camphor oil was one of the ingredients used by ancient Egyptians for mummification.[11]

Solid camphor releases fumes that form a rust-preventative coating and is therefore stored in tool chests to protect tools against rust.[12]

Culinary

In ancient and medieval Europe, camphor was used as an ingredient in sweets. It was used in a wide variety of both savory and sweet dishes in medieval Arabic language cookbooks, such as al-Kitab al-Ṭabikh compiled by ibn Sayyâr al-Warrâq in the 10th century,[13] and an anonymous Andalusian cookbook of the 13th century.[14] It also appears in sweet and savory dishes in a book written in the late 15th century for the sultans of Mandu, the Ni'matnama.[15] An early international trade in it made camphor widely known throughout Arabia in pre-Islamic times, as it is mentioned in the Quran 76:5 as a flavoring for drinks.[16] By the 13th century, it was used in recipes everywhere in the Muslim world, ranging from main dishes such as tharid and stew to desserts.[14]

Currently, camphor is used as a flavoring, mostly for sweets, in Asia. It is widely used in cooking, mainly for dessert dishes, in India where it is known as kachha karpooram or "pachha karpoora" ("crude/raw camphor"), in (Telugu:పచ్చ కర్పూరo), (Tamil:பச்சைக் கற்பூரம்), (Kannada:ಪಚ್ಚ ಕರ್ಪೂರ), and is available in Indian grocery stores where it is labeled as "edible camphor".

Medicinal

Camphor is readily absorbed through the skin producing either a coolness or warmth sensation,[17][18] and acts as slight local anesthetic and antimicrobial substance. There are anti-itch gels and cooling gels with camphor as the active ingredient. It is used carefully and in low dosage in baby oil for its calming effects.

Camphor is an active ingredient (along with menthol) in vapor-steam products, such as Vicks VapoRub. It is used as a cough suppressant[19] and as a decongestant.[19] It is also used for aromatherapy.

Camphor may also be administered orally in small quantities (50 mg) for minor heart symptoms and fatigue.[20] Through much of the 1900s this was sold under the trade name Musterole; production ceased in the 1990s.

Camphor was used in ancient Sumatra to treat sprains, swellings, and inflammation.[21] Camphor is a component of paregoric, an opium/camphor tincture from the 18th century. Also in the 18th century, camphor was used by Auenbrugger in the treatment of mania.[22] Based on Hahnemann's writings, camphor (dissolved in alcohol) was also successfully used to treat the 1854-1855 cholera epidemics in Naples.[23]

Small dose

Its effects on the body include tachycardia, vasodilation in skin (flushing), slower breathing, reduced appetite, increased secretions and excretions such as perspiration, diuretic. [24]

The sensation of heat or cold that camphor produces is caused by activating the ion channel TRPV3.[18][25]

Large dose toxicity

Camphor is poisonous in large doses. It produces symptoms of irritability, disorientation, lethargy, muscle spasms, vomiting, abdominal cramps, convulsions, and seizures.[26][27][28] Lethal doses in adults are in the range 50–500 mg/kg (orally). Generally, two grams cause serious toxicity and four grams are potentially lethal.[29]

Regulation

In 1980, the US Food and Drug Administration set a limit of 11% allowable camphor in consumer products, and totally banned products labeled as camphorated oil, camphor oil, camphor liniment, and camphorated liniment (except "white camphor essential oil", which contains no significant amount of camphor). Since alternative treatments exist, medicinal use of camphor is discouraged by the FDA, except for skin-related uses, such as medicated powders, which contain only small amounts of camphor.

Hindu religious ceremonies

Camphor is widely used in Hindu religious ceremonies. Hindus worship a holy flame by burning camphor, which forms an important part of many religious ceremonies. Camphor is used in the Mahashivratri celebrations of Shiva, the Hindu god of destruction and (re)creation. As a natural pitch substance, it burns cool without leaving any ash residue, which symbolizes consciousness. Most temples in southern India have stopped lighting paraffin wax camphor in the main sanctum sanctorum because it produces much soot; however, they still burn it in open areas.

In Gujarat, Tamil Nadu, Andhra Pradesh, Uttar Pradesh, Madhya Pradesh, Maharashtra, Karnataka, Kerala & Andamans, camphor is the primary ingredient in any holy ritual. At the end of a holy ritual, camphor flame (called aarti) is lit for the deities.

In some Hindu puja ceremonies, camphor is burned on a special plate for performing the aarti ceremony. This type of camphor, the processed white crystalline paraffin wax kind, is sold at Indian grocery stores.

See also

References

  1. ^ The Merck Index, 7th edition, Merck & Co., Rahway, New Jersey, USA, 1960
  2. ^ Handbook of Chemistry and Physics, CRC Press, Ann Arbor, Michigan, USA
  3. ^ a b c d "NIOSH Pocket Guide to Chemical Hazards #0096".  
  4. ^ a b c "Camphor (synthetic)". National Institute for Occupational Safety and Health (NIOSH). 4 December 2014. Retrieved 19 February 2015. 
  5. ^ Mann JC, Hobbs JB, Banthorpe DV, Harborne JB (1994). Natural products: their chemistry and biological significance. Harlow, Essex, England: Longman Scientific & Technical. pp. 309–11.  
  6. ^ Camphor at the Online Etymology Dictionary
  7. ^ Drakard, Jane (1989). "An Indian Ocean Port: Sources for the Earlier History of Barus". Archipel 37: 53-82. Retrieved 9 October 2015. 
  8. ^ Chakrabarti K,Chakrabarti R, Chattopadhyay KK, Chaudhuri S, Pal AK (1998). "Nano-diamond films produced from CVD of camphor". Diam Relat Mater 7 (6): 845–52.  
  9. ^ Kumar M, Ando Y (2007). "Carbon Nanotubes from Camphor: An Environment-Friendly Nanotechnology". J Phys Conf Ser. 61: 643–6.  
  10. ^ The Housekeeper's Almanac, or, the Young Wife's Oracle! for 1840!. No. 134. New-York: Elton, 1840. Print.
  11. ^ http://www.newscientist.com/article/dn1475-mummymaking-complexity-revealed.html#.VKVwGMksoow
  12. ^ Tips for Cabinet Making Shops
  13. ^ Nasrallah, Nawal (2007). Annals of the Caliphs' Kitchens: Ibn Sayyâr al-Warrâq's Tenth-century Baghdadi Cookbook. Islamic History and Civilization, 70. Leiden, The Netherlands: Brill.  
  14. ^ a b An Anonymous Andalusian cookbook of the 13th century, translated from the original Arabic by Charles Perry
  15. ^ Titley, Norah M. (2004). The Ni'matnama Manuscript of the Sultans of Mandu: The Sultan's Book of Delights. Routledge Studies in South Asia. London, UK: Routledge.  
  16. ^ [Quran 76:5]
  17. ^ Moqrich, A.; Hwang, Sun Wook; Earley, Taryn J.; Petrus, Matt J.; Murray, Amber N.; Spencer, Kathryn S. R.; Andahazy, Mary; Story, Gina M.; Patapoutian, Ardem (2005). "Impaired Thermosensation in Mice Lacking TRPV3, a Heat and Camphor Sensor in the Skin". Science 307 (5714): 1468–72.  
  18. ^ a b Green, B. G. (1990). "Sensory characteristics of camphor". The Journal of investigative dermatology 94 (5): 662–6.  
  19. ^ a b http://www.drugs.com/cdi/camphor-liquid.html
  20. ^ Lääketietokeskus. Lääkevalmisteet Pharmaca Fennica 1996, p. 814.
  21. ^ Miller, Charles. History of Sumatra : An account of Sumatra. p. 121. 
  22. ^ Pearce, J.M.S. (2008). "Leopold Auenbrugger: Camphor-Induced Epilepsy – Remedy for Manic Psychosis". European Neurology 59 (1–2): 105–7.  
  23. ^ Bayes (1866). "Cholera, as Treated by Dr. Rubini". The American Homoeopathic Review 6 (11–12): 401–3. 
  24. ^ Church, John (1797). An inaugural dissertation on camphor: submitted to the examination of the Rev. John Ewing, S.S.T.P. provost ; the trustees & medical faculty of the University of Pennsylvania, on the 12th of May, 1797 ; for the degree of Doctor of Medicine. University of Philadelphia: Printed by John Thompson. Retrieved January 18, 2013. 
  25. ^ Moqrich, A.; Hwang, Sun Wook; Earley, Taryn J.; Petrus, Matt J.; Murray, Amber N.; Spencer, Kathryn S. R.; Andahazy, Mary; Story, Gina M.; Patapoutian, Ardem (2005). "Impaired Thermosensation in Mice Lacking TRPV3, a Heat and Camphor Sensor in the Skin". Science 307 (5714): 1468–72.  
  26. ^ "Camphor overdose". Medline. NIH. Retrieved January 19, 2012. 
  27. ^ Martin D, Valdez J, Boren J, Mayersohn M (Oct 2004). "Dermal absorption of camphor, menthol, and methyl salicylate in humans". Journal of Clinical Pharmacology 44 (10): 1151–7.  
  28. ^ Uc A, Bishop WP, Sanders KD (Jun 2000). "Camphor hepatotoxicity". Southern Medical Journal 93 (6): 596–8.  
  29. ^ "Poisons Information Monograph: Camphor". International Programme on Chemical Safety. 

External links