1-Methylcyclopropene (1-MCP) is a cyclopropene derivative used as a synthetic plant growth regulator. It is structurally related to the natural plant hormone

ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon doub ...

and it is used commercially to slow down the ripening of fruit and to help maintain the freshness of

cut flowers Cut flowers are flowers and flower buds (often with some Plant stem, stem and leaf) that have been cut from the plant bearing it. It is removed from the plant for decorative use. Cut greens are leaves with or without stems added to the cut flow ...

Synthesis

1-Methylcyclopropene is synthesized by the reaction of methallyl chloride and

phenyllithium Phenyllithium is an organometallic agent with the empirical formula . It is most commonly used as a metalating agent in organic syntheses and a substitute for Grignard reagents for introducing phenyl groups in organic syntheses. Crystalline phenyl ...

, which functions as a base: The phenyllithium should be free of lithium halides. The corresponding reaction of allyl chloride and phenyllithium main affords cyclopropylbenzene.

Isomers

Methylcyclopropene can refer to either of two

isomers In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the existence or possibili ...

, 1-methylcyclopropene covered in this article, or 3-methylcyclopropene which is not covered in this article. 2-methylcyclopropene would be an incorrect name for 1-methylcyclopropene. Also note: methylcyclopropane is yet a different

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

, which is a

cycloalkane In organic chemistry, the cycloalkanes (also called naphthenes, but distinct from naphthalene) are the ring (chemistry), monocyclic Saturated and unsaturated compounds, saturated hydrocarbons. In other words, a cycloalkane consists only of hydroge ...

with the formula C₄H₈.

Mechanism of action

Ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon doub ...

is a gas acting at trace levels (typically between a few tenths and a few thousands ppm in the gas atmosphere) throughout the life of a plant by stimulating or regulating various processes such as the

ripening Ripening is a process in fruits that causes them to become more palatable. In general, fruit becomes sweeter, less green, and softer as it ripens. Even though the acidity of fruit increases as it ripens, the higher acidity level does not make t ...

of climacteric fruit, the opening of flowers ( dehiscence process), and the shedding of leaves ( abscission process). The

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...

of 1-MCP involves its tightly binding to the ethylene receptor in plants, thereby blocking the effects of ethylene (

competitive inhibitor Competitive inhibition is interruption of a chemical pathway owing to one chemical substance inhibiting the effect of another by competing with it for binding or bonding. Any metabolic or chemical messenger system can potentially be affected b ...

Commercial use

1-MCP is used commercially to maintain the freshness of ornamental plants and flowers and preventing the ripening of fruits. It is used in enclosed sites, such as coolers, truck trailers, greenhouses, storage facilities, and shipping containers.1-Methylcyclopropene Fact Sheet
U.S. Environmental Protection Agency Under the brand name EthylBloc, 1-MCP was approved in by the U.S. Environmental Protection Agency for use on ornamental crops. For cut flowers, potted flowers, and bedding, nursery and foliage plants, 1-MCP prevents or delays wilting, leaf yellowing, opening, and death. Under the brand name SmartFresh, 1-MCP is used in the agriculture industry by growers, packers, and shippers to prevent or delay the natural ripening process. The use of 1-MCP in agricultural products including apples, kiwifruit, tomatoes, bananas, plums, persimmons, avocados, and melons has been approved and accepted for use in more than 34 countries including the European Union and the United States. Although benefiting from fresher produce and lower cost, the consumer however may be purchasing fruit that is older than expected. 1-MCP is also being developed as a crop protection technique. By spraying 1-MCP on growing field crops during times of stress, the crops may be protected from moderate heat and drought conditions.Syngenta-Agrofresh Alliance: New crop protection technology takes aim at row crops
, ''Farm Industry News'', Jan 18, 2008

References

{{DEFAULTSORT:Methylcyclopropene, 1- Cyclopropenes Plant growth regulators

Synthesis

Isomers

Mechanism of action

Commercial use

See also

References