Jasmonic acid

Structural formula
	Structure of (-) - jasmonic acid
General
Surname	Jasmonic acid
other names	YES; (-) - Jasmonic acid; (1 R , 2 R ) -3-Oxo-2-pent-2-enyl-cyclopentane acetic acid;
Molecular formula	C 12 H 18 O 3
Brief description	viscous oil
External identifiers / databases
PubChem	5281166
ChemSpider	4444606
Wikidata	Q415311
properties
Molar mass	210.27 g · mol -1
Physical state	liquid
boiling point	125 ° C (0.13 Pa)
Refractive index	1.4885 (at 19 ° C)
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Jasmonic acid is a ubiquitous phytohormone and the basic structure of the jasmonate group , whose function is to regulate the growth and aging of the leaves and roots of plants in particular. Jasmonic acid plays a decisive role as an elicitor signal in a large number of plants in the defense against biotic and abiotic stress. The most important derivative is its methyl ester, methyl jasmonate .

Stereochemistry

1a : (-) - jasmonic acid; 1b : (+) - jasmonic acid; 2a : (+) - epi-jasmonic acid; 2b : (-) - epi-jasmonic acid

Jasmonic acid is a chiral compound that contains two asymmetrically substituted carbon atoms. The compound can therefore exist in four different stereochemical forms. The pairs (-) - / (+) - jasmonic acid ( 1a / 1b ) and (+) - epi - / (-) - epi-jasmonic acid ( 2a / 2b ) each represent mirror-image molecules , i.e. they are enantiomers . The pairings ( 1a / 2a ) and ( 1b / 2b ) are diastereomers .

Of course, mainly (-) - jasmonic acid and its methyl ester, (-) - methyl jasmonate , occur.

biosynthesis

From α-linolenic acid ( 1 ) is peroxidized by 13-lipoxygenase (13-LOX) ( A ) to 13 ( S ) -hydroperoxylinolenic acid ( 2 ). This produces an epoxide, the 12,13 ( S ) -epoxy-9 ( Z ), 11 ( E ), 15 ( Z ) -octadecatrienoic acid ( 3 ), which catalyzes the 13- allene oxide synthase (13-AOS) ( B ). An allene oxide cyclase (AOC) ( C ) finally cyclizes the epoxide to 12-oxo-phytodienonic acid (OPDA) ( 4 ). In the course of further reactions, (+) - 7-iso-jasmonic acid ( 5a ) is formed, which is epimerized to form the stable (-) - jasmonic acid ( 5b ).

Brady Vick and Don Zimmerman were able to explain the biosynthetic pathway of jasmonates. Jasmonic acid is formed from α-linolenic acid . The synthesis takes place in two spatially separated sub-steps. The first step is catalyzed by the enzymes 13-lipoxygenase (13-LOX), 13-allene oxide synthase (13-AOS) and allene oxide cyclase (AOC), which are localized in the chloroplastid membrane. This creates the intermediate product cis - (+) - 12-oxophytodienoic acid (OPDA). OPDA or its CoA ester is passed on to the peroxisomes in the second sub-step . There the cyclopentane ring is reduced by OPDA. Then the enzymes of the β-oxidation of the fatty acids also catalyze the carboxyl side chain of OPDA and (+) - 7-iso-jasmonic acid or the diastereomer (-) - jasmonic acid is formed.

Reactions

By reduction , for example using sodium borohydride , jasmonic acid can be used for the synthesis of cucurbic acid . The reduction proceeds only with weak diastereoselectivity .

literature

Ushio Sankawa, Derek HR Barton, Koji Nakanishi, Otto Meth-Cohn: Comprehensive Natural Products Chemistry: Polyketides and Other Secondary Metabolites Including Fatty Acids and Their Derivatives , ISBN 0-08-043153-4 .
C. Delker, I. Stenzel, B. haus, O. Miersch, I. Feussner, C. Wasternack: Jasmonate biosynthesis in Arabidopsis thaliana — enzymes, products, regulation . Plant biology (Stuttgart, Germany), 2006 May; 8 (3): 297-306

Individual evidence

↑ ^a ^b ^c Entry on jasmonic acid. In: Römpp Online . Georg Thieme Verlag, accessed on May 7, 2013.
↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ Lalit M. Srivastava: Plant Growth and Development: Hormones and Environment . Academic Press, 2002, ISBN 0-08-051403-0 , pp. 252 ( limited preview in Google Book search).
↑ Vick, BA. and Zimmerman, DC. (1984): Biosynthesis of Jasmonic Acid by Several Plant Species . In: Plant Physiol. 75 (2); 458-461; PMID 16663643 ; PDF (free full text access)
↑ Vick, BA. and Zimmerman, DC. (1987): Pathways of Fatty Acid Hydroperoxide Metabolism in Spinach Leaf Chloroplasts . In: Plant Physiol. 85 (4); 1073-1078; PMID 16665806 ; PDF (free full text access)
↑ Claus Wasternack: Jasmonate - mode of action , accessed on May 13, 2013.
↑ W. Dathe, C. Schindler, G. Schneider, J. Schmidt, A. Porzel, E. Jensen, I. Yamaguchi; Phytochemistry 1991 , 30 , (6), 1909-1914.

[Roempp-1] Entry on jasmonic acid. In: Römpp Online . Georg Thieme Verlag, accessed on May 7, 2013.

[NV-2] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[3] Lalit M. Srivastava: Plant Growth and Development: Hormones and Environment . Academic Press, 2002, ISBN 0-08-051403-0 , pp. 252 ( limited preview in Google Book search).

[4] Vick, BA. and Zimmerman, DC. (1984): Biosynthesis of Jasmonic Acid by Several Plant Species . In: Plant Physiol. 75 (2); 458-461; PMID 16663643 ; PDF (free full text access)

[5] Vick, BA. and Zimmerman, DC. (1987): Pathways of Fatty Acid Hydroperoxide Metabolism in Spinach Leaf Chloroplasts . In: Plant Physiol. 85 (4); 1073-1078; PMID 16665806 ; PDF (free full text access)

[6] Claus Wasternack: Jasmonate - mode of action , accessed on May 13, 2013.

[7] W. Dathe, C. Schindler, G. Schneider, J. Schmidt, A. Porzel, E. Jensen, I. Yamaguchi; Phytochemistry 1991 , 30 , (6), 1909-1914.