Verbenone
Encyclopedia
Verbenone is a natural organic compound
classified as a terpene
which is found naturally in a variety of plants. The chemical has a pleasant characteristic odor. Besides being a natural constituent of plants, it and its analogs are insect pheromones. In particular, verbenone has an important role in the control of the Southern pine bark beetle.
terpene. It is the primary constituent of the oil of Spanish verbena, hence its name; it is also found in the oil of rosemary
. It is nearly insoluble in water, but miscible with most organic solvents.
Verbenone can be readily prepared synthetically by the oxidation
of the more common terpene α-pinene
:
Verbenone can then be converted into chrysanthenone
through a photochemical
rearrangement reaction
:
(Dendroctonus frontalis) is a major threat to pine trees in the southeastern United States. Its reproductive cycle is controlled by varying ratios of certain natural chemicals, including verbenone. To reproduce, pine bark beetles aggregate in large numbers in their host pine trees. At the beginning of an attack, various chemicals produced by infested trees and by the beetles attract additional beetles of the same species. When the numbers of adults and larvae approach the maximum that the tree can support, antiaggregation signal chemicals are produced to keep additional beetles away. Forest managers frequently try to control infestations of the Southern pine bark beetle by cutting down and sometimes burning infested trees and nearby healthy trees. They then hang verbenone pouches on nearby susceptible healthy trees to repel and confuse the beetles.
s high in verbenone content) are used in perfume
ry, aromatherapy
, herbal teas, spice
s and herbal remedies
. The L-isomer
is used as a cough suppressant
under the name levoverbenone
. Verbenone may also have antimicrobial properties.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
classified as a terpene
Terpene
Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeterium. They are often strong smelling and thus may have had a protective...
which is found naturally in a variety of plants. The chemical has a pleasant characteristic odor. Besides being a natural constituent of plants, it and its analogs are insect pheromones. In particular, verbenone has an important role in the control of the Southern pine bark beetle.
Chemistry
While verbenone is a terpene, more specifically the compound is also a bicyclic ketoneKetone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
terpene. It is the primary constituent of the oil of Spanish verbena, hence its name; it is also found in the oil of rosemary
Rosemary
Rosemary, , is a woody, perennial herb with fragrant, evergreen, needle-like leaves and white, pink, purple or blue flowers, native to the Mediterranean region. It is a member of the mint family Lamiaceae, which includes many other herbs, and is one of two species in the genus Rosmarinus...
. It is nearly insoluble in water, but miscible with most organic solvents.
Verbenone can be readily prepared synthetically by the oxidation
Redox
Redox reactions describe all chemical reactions in which atoms have their oxidation state changed....
of the more common terpene α-pinene
Alpha-Pinene
α-Pinene is an organic compound of the terpene class, one of two isomers of pinene. It is an alkene and it contains a reactive four-membered ring. It is found in the oils of many species of many coniferous trees, notably the pine. It is also found in the essential oil of rosemary...
:
Verbenone can then be converted into chrysanthenone
Chrysanthenone
Chrysanthenone is a terpene. It can be produced from its isomer verbenone in a photochemical rearrangement reaction.-External links:*...
through a photochemical
Photochemistry
Photochemistry, a sub-discipline of chemistry, is the study of chemical reactions that proceed with the absorption of light by atoms or molecules.. Everyday examples include photosynthesis, the degradation of plastics and the formation of vitamin D with sunlight.-Principles:Light is a type of...
rearrangement reaction
Rearrangement reaction
A rearrangement reaction is a broad class of organic reactions where the carbon skeleton of a molecule is rearranged to give a structural isomer of the original molecule. Often a substituent moves from one atom to another atom in the same molecule...
:
Use for insect control
The Southern pine bark beetleBark beetle
A bark beetle is one of approximately 220 genera with 6,000 species of beetles in the subfamily Scolytinae. Traditionally, this was considered a distinct family Scolytidae, but now it is understood that bark beetles are in fact very specialized members of the "true weevil" family...
(Dendroctonus frontalis) is a major threat to pine trees in the southeastern United States. Its reproductive cycle is controlled by varying ratios of certain natural chemicals, including verbenone. To reproduce, pine bark beetles aggregate in large numbers in their host pine trees. At the beginning of an attack, various chemicals produced by infested trees and by the beetles attract additional beetles of the same species. When the numbers of adults and larvae approach the maximum that the tree can support, antiaggregation signal chemicals are produced to keep additional beetles away. Forest managers frequently try to control infestations of the Southern pine bark beetle by cutting down and sometimes burning infested trees and nearby healthy trees. They then hang verbenone pouches on nearby susceptible healthy trees to repel and confuse the beetles.
Other uses
Because of its pleasant aroma, verbenone (or essential oilEssential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
s high in verbenone content) are used in 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"...
ry, aromatherapy
Aromatherapy
Aromatherapy is a form of alternative medicine that uses volatile plant materials, known as essential oils, and other aromatic compounds for the purpose of altering a person's mind, mood, cognitive function or health....
, herbal teas, spice
Spice
A spice is a dried seed, fruit, root, bark, or vegetative substance used in nutritionally insignificant quantities as a food additive for flavor, color, or as a preservative that kills harmful bacteria or prevents their growth. It may be used to flavour a dish or to hide other flavours...
s and herbal remedies
Herbalism
Herbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, herblore, and phytotherapy...
. The L-isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
is used as a cough suppressant
Cough medicine
A cough medicine is a medicinal drug used in an attempt to treat coughing and related conditions. For dry coughs, treatment with cough suppressants may be attempted to suppress the body's urge to cough...
under the name levoverbenone
Levoverbenone
Levoverbenone is an expectorant. It is the L-isomer of verbenone....
. Verbenone may also have antimicrobial properties.
External links
- U.S. Environmental Protection Agency Fact sheet for verbenone.