1-methylcyclopropene

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Structural formula
Structural formula of 1-methylcyclopropene
General
Surname 1-methylcyclopropene
Molecular formula C 4 H 6
External identifiers / databases
CAS number 3100-04-7
EC number 608-567-1
ECHA InfoCard 100.130.871
PubChem 151080
Wikidata Q161651
properties
Molar mass 54 g · mol -1
Physical state

gaseous

Melting point

below −100 ° C

boiling point

4.7 ° C

Vapor pressure

2 · 10 5 Pa (25 ° C)

solubility
safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

1-Methylcyclopropene ( 1-MCP ) is a gaseous , unsaturated, cyclic hydrocarbon from the group of cycloalkenes .

Presentation and extraction

1-methylcyclopropene can be achieved by cyclization of methacrylic acid chloride by means of sodium in liquid ammonia are produced. The reaction of methallyl chloride with sodium amide also gives the target compound.

use

1-methylcyclopropene is used in fruit and vegetable growing to delay the natural aging of the harvested products. It is also used in the production of cut and potted flowers to slow down the wilting process. Even a single fumigation prevented by coating the ethylene - receptors in the cell membranes of a recording of the biochemical maturing or Welkungsprozess triggering ethylene gas through the cell, as MCP-1 at concentrations of a few ppb is effective. The further ripening and wilting process is significantly slowed down. The effect remains as long as the treated products are cooled; After a temperature increase, new ethylene receptors can be formed and the ripening or wilting process continues.

Effect of 1-MCP: left untreated pear, right treated with 1-MCP; the storage time was always the same

Apple storage

Use on apples is permitted in the EU and Switzerland; use does not have to be labeled. The substance cannot be used for all types, as it sometimes promotes physiological diseases.

Are suitable:

Are conditionally suitable:

The following are unsuitable:

criticism

After gassing with 1-MCP, the consumer is not able to determine the age of the fruit; for example, whether it's a week or a year old. However, aging takes place, e.g. B. in the breakdown of vitamin C.

Admission status

1-MCP has been approved as a fumigant since 2005 in the EU , the USA and some other countries around the world and is viewed as a supplement and improvement to conventional cooling and CA storage methods.

Forms of trade

Trade names for 1-MCP formulations are SmartFresh , EthylBloc and FreshStart from the US manufacturer AgroFresh or Fysium from the US manufacturer Pace International LLC. In a SmartFresh formulation, the gaseous 1-MCP is packaged in cyclically closed oligosaccharides , the so-called cyclodextrins . These cyclodextrins are sugar molecules that dissolve in water and thus release the 1-MCP. As a manufacturer of cyclodextrins, the company Wacker Chemie is involved in the SmartFresh formulation , which produces around 5000 tons of cyclodextrins annually.

literature

Individual evidence

  1. ↑ a b c d e f g h i j Federal Office for Consumer Protection and Food Safety (BVL): 1-methylcyclopropene . February 2006 PDF (19 kB) .
  2. ↑ Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of 1-methylcycloprop-1-ene in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on April 18, 2018, is reproduced from a self-classification by the distributor .
  3. ↑ Okazaki, R .; O-Oka, M .; Akiyama, T .: in J. Am. Chem. Soc. 109 (1987) 5413.
  4. ↑ Fisher, F .; Applequist, DE: Synthesis of 1-Methylcyclopropene in J. Org. Chem. 30 (1965) 2089-2090, doi : 10.1021 / jo01017a531 .
  5. ↑ Serek M, Woltering EJ, Sisler EC, Frello S, Sriskandarajah S: Controlling ethylene responses in flowers at the receptor level. , Biotechnol Adv. 2006; 24 (4): 368-381, Review, PMID 16584864 .
  6. ^ A b Wacker Chemie : Smartfresh , accessed October 7, 2013.
  7. ↑ a b AgroFresh: SmartFresh Technology ( Memento from December 8, 2015 in the Internet Archive ) (in English), accessed on December 1, 2015.
  8. ↑ Residues in apples - organic is better. In: test.de. July 27, 2006, accessed May 27, 2019 .
  9. ↑ Yves Demuth: “Marktfrische” Swiss apples: “Fresh” from last year. In: observer.ch . August 19, 2019, accessed August 24, 2019 .
  10. ↑ OVA Jork's work diary 2014 , p. 276
  11. ↑ Reinhard Wolff: Ancient apples always fresh. In: the daily newspaper. May 21, 2005.
  12. ↑ MCP - Effects in Apple Storage. (No longer available online.) In: obstbau.rlp.de. MUEEF , archived from the original on October 21, 2013 ; accessed on May 8, 2020 .
  13. ↑ General Directorate Health and Food Safety of the European Commission: Entry on 1-methylcyclopropene in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on December 7, 2019.