Safrole
Encyclopedia
Safrole, also known as shikimol, is a phenylpropene
. It is a colorless or slightly yellow oily liquid. It is typically extracted from the root-bark or the fruit of sassafras
plants in the form of sassafras oil (although commercially available sassafras oil is usually devoid of safrole via a rule passed by the FDA in 1960, see here), or synthesized from other related methylenedioxy
compounds. It is the principal component of brown camphor
oil, and is found in small amounts in a wide variety of plants, where it functions as a natural pesticide
. Ocotea cymbarum oil made from Ocotea pretiosa, a plant growing in Brazil
, and sassafras oil made from Sassafras albidum
, a tree growing in eastern North America
, are the main natural sources for safrole. It has a characteristic "sweet-shop" aroma.
It is a precursor
in the synthesis of the insecticide
synergist piperonyl butoxide
and the empathogenic/entactogenic drug MDMA.
in rats, and considered by the European Commission on Health and consumer protection to be genotoxic and carcinogenic. It naturally occurs in a variety of spices such as cinnamon
, nutmeg
, black pepper
and herbs such as basil
. In that role safrole is believed, although not proven, to make a small but measurable contribution to the overall incidence of human cancer, equal to the hazards presented by orange juice
(due to limonene
) and tomatoes (caffeic acid
). In the United States
, it was once widely used as a food additive in root beer
, sassafras tea, and other common goods, but was banned by the Food and Drug Administration
(FDA) after its carcinogenicity in rats was discovered. Today, safrole is also banned for use in soap
and perfume
s by the International Fragrance Association
.
According to a 1977 study of the metabolites of safrole in both rats and humans, two carcinogenic metabolites of safrole found in the urine of rats, 1'-hydroxysafrole and 3'-hydroxyisosafrole, were not found in human urine.
as well as piperonal
are Category I precursors under regulation No 273/2004 of the European Community. In the US, safrole is currently a List I chemical
. The root bark of American sassafras
contains a few percent of steam volatile oil which is typically 75% safrole. Attempts to access safrole from this source are generally not successful because the yield is low and the effort required to get useful amounts of material is great. Safrole is listed as a Table I precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances
.
Phenylpropene
Phenylpropenes, propenylphenols or allylbenzenes are a class of phenylpropanoids, a type of polyphenols.The phenylpropenes, including eugenol, chavicol, safrole and estragole, are derived from the monolignols. These compounds are the primary constituents of various essential oils....
. It is a colorless or slightly yellow oily liquid. It is typically extracted from the root-bark or the fruit of sassafras
Sassafras
Sassafras is a genus of three extant and one extinct species of deciduous trees in the family Lauraceae, native to eastern North America and eastern Asia.-Overview:...
plants in the form of sassafras oil (although commercially available sassafras oil is usually devoid of safrole via a rule passed by the FDA in 1960, see here), or synthesized from other related methylenedioxy
Methylenedioxy
Methylenedioxy in the field of chemistry, particularly in organic chemistry, is the name for a functional group with the structural formula R-O-CH2-O-R' which is connected to the rest of a molecule by two chemical bonds. The methylenedioxy group consists of two oxygen atoms connected to a methylene...
compounds. It is the principal component of brown camphor
Camphor
Camphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the camphor laurel , a large evergreen tree found in Asia and also of Dryobalanops aromatica, a giant of the Bornean forests...
oil, and is found in small amounts in a wide variety of plants, where it functions as a natural pesticide
Pesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
. Ocotea cymbarum oil made from Ocotea pretiosa, a plant growing in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, and sassafras oil made from Sassafras albidum
Sassafras albidum
Sassafras albidum is a species of Sassafras native to eastern North America, from southern Maine and southern Ontario west to Iowa, and south to central Florida and eastern Texas. It occurs throughout the eastern deciduous forest habitat type, at altitudes of sea level up to 1,500 m...
, a tree growing in eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, are the main natural sources for safrole. It has a characteristic "sweet-shop" aroma.
It is a precursor
Precursor (chemistry)
In chemistry, a precursor is a compound that participates in the chemical reaction that produces another compound. In biochemistry, the term "precursor" is used more specifically to refer to a chemical compound preceding another in a metabolic pathway....
in the synthesis of the insecticide
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
synergist piperonyl butoxide
Piperonyl butoxide
Piperonyl butoxide is an organic compound used as pesticide synergist, especially for pyrethroids and rotenone. It does not by itself have pesticidal properties. However, when added to insecticide mixtures, typically pyrethrin, pyrethroid, and carbamate insecticides, their potency is increased...
and the empathogenic/entactogenic drug MDMA.
Carcinogenicity
Safrole is regarded by the U.S. government to be a weak carcinogenCarcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
in rats, and considered by the European Commission on Health and consumer protection to be genotoxic and carcinogenic. It naturally occurs in a variety of spices such as cinnamon
Cinnamon
Cinnamon is a spice obtained from the inner bark of several trees from the genus Cinnamomum that is used in both sweet and savoury foods...
, nutmeg
Nutmeg
The nutmeg tree is any of several species of trees in genus Myristica. The most important commercial species is Myristica fragrans, an evergreen tree indigenous to the Banda Islands in the Moluccas of Indonesia...
, black pepper
Black pepper
Black pepper is a flowering vine in the family Piperaceae, cultivated for its fruit, which is usually dried and used as a spice and seasoning. The fruit, known as a peppercorn when dried, is approximately in diameter, dark red when fully mature, and, like all drupes, contains a single seed...
and herbs such as basil
Basil
Basil, or Sweet Basil, is a common name for the culinary herb Ocimum basilicum , of the family Lamiaceae , sometimes known as Saint Joseph's Wort in some English-speaking countries....
. In that role safrole is believed, although not proven, to make a small but measurable contribution to the overall incidence of human cancer, equal to the hazards presented by orange juice
Orange juice
Orange juice is a popular beverage made from oranges. It is made by extraction from the fresh fruit, by desiccation and subsequent reconstitution of dried juice, or by concentration of the juice and the subsequent addition of water to the concentrate...
(due to limonene
Limonene
Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene. The more common D isomer possesses a strong smell of oranges. It is used in chemical synthesis as a precursor to carvone and as a renewably-based solvent in cleaning products....
) and tomatoes (caffeic acid
Caffeic acid
Caffeic acid is a hydroxycinnamic acid, a naturally occurring organic compound. This yellow solid consists of both phenolic and acrylic functional groups...
). In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, it was once widely used as a food additive in root beer
Root beer
Root beer is a carbonated, sweetened beverage, originally made using the root of a sassafras plant as the primary flavor. Root beer, popularized in North America, comes in two forms: alcoholic and soft drink. The historical root beer was analogous to small beer in that the process provided a drink...
, sassafras tea, and other common goods, but was banned by the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
(FDA) after its carcinogenicity in rats was discovered. Today, safrole is also banned for use in soap
Soap
In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...
and perfume
Perfume
Perfume is a mixture of fragrant essential oils and/or aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces "a pleasant scent"...
s by the International Fragrance Association
International Fragrance Association
The International Fragrance Association is the official representative body of the fragrance industry worldwide. Its main purpose is to ensure the safety of fragrance materials through a dedicated science program. IFRA publishes a list of usage standards for fragrance materials based on the...
.
According to a 1977 study of the metabolites of safrole in both rats and humans, two carcinogenic metabolites of safrole found in the urine of rats, 1'-hydroxysafrole and 3'-hydroxyisosafrole, were not found in human urine.
Use in MDMA manufacture
Due to its role in the manufacture of MDMA, safrole and isosafroleIsosafrole
Isosafrole is a phenylpropene, a type of aromatic organic chemical with a smell similar to anise or licorice. It is found in small amounts in various essential oils, but is most commonly obtained by isomerizing the plant oil safrole....
as well as piperonal
Piperonal
Piperonal, also known as heliotropin, is an aromatic aldehyde that comes as transparent crystals, C8H6O3, and has a floral odor commonly described as being similar to that of vanillin and cherry. It is used as flavoring and in perfume. It can be obtained by oxidation of piperonyl alcohol or the...
are Category I precursors under regulation No 273/2004 of the European Community. In the US, safrole is currently a List I chemical
DEA list of chemicals
The United States Drug Enforcement Administration maintains lists regarding not only the classification of illicit drugs . It also maintains List I of chemicals and List II of chemicals, which contain chemicals which are used to manufacture the controlled substances/illicit drugs...
. The root bark of American sassafras
Sassafras
Sassafras is a genus of three extant and one extinct species of deciduous trees in the family Lauraceae, native to eastern North America and eastern Asia.-Overview:...
contains a few percent of steam volatile oil which is typically 75% safrole. Attempts to access safrole from this source are generally not successful because the yield is low and the effort required to get useful amounts of material is great. Safrole is listed as a Table I precursor under the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances
United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances
The United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances of 1988 is one of three major drug control treaties currently in force. It provides additional legal mechanisms for enforcing the 1961 Single Convention on Narcotic Drugs and the 1971 Convention on...
.