Sinapic acid
Structural formula | ||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
General | ||||||||||||||||
Surname | Sinapic acid | |||||||||||||||
other names |
|
|||||||||||||||
Molecular formula | C 11 H 12 O 5 | |||||||||||||||
External identifiers / databases | ||||||||||||||||
|
||||||||||||||||
properties | ||||||||||||||||
Molar mass | 224.21 g mol −1 | |||||||||||||||
Physical state |
firmly |
|||||||||||||||
Melting point |
202 ° C |
|||||||||||||||
boiling point |
decomposition |
|||||||||||||||
solubility | ||||||||||||||||
safety instructions | ||||||||||||||||
|
||||||||||||||||
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Sinapic acid ( trans -3,5-dimethoxy-4-hydroxycinnamic acid) belongs to the group of phenylpropanoids or phenolic acids , more precisely the cinnamic acid derivatives. With bases it forms partly crystallizable salts which decompose in the air.
Occurrence in nature
Sinapic acid occurs naturally in rapeseed . The total content of phenolic acids in rapeseed meal is significantly higher than in other oil crops (e.g. peanut : 63.6 mg / 100 g, rapeseed: 639.9 mg / 100 g). Sinapic acid and its esters make up the largest proportion of phenolic acids in rapeseed with 70 to 85% . Sinapic acid is produced in the plant as a product of cinnamic acid biosynthesis . Starting from the amino acid phenylalanine is produced by deamination using the enzyme phenylalanine ammonia lyase ( EC 4.3.1.5 ), the cinnamic acid . Sinapic acid is produced from this via caffeic acid , ferulic acid and 5-hydroxyferulic acid.
In plants, sinapic acid esters prevent the short-wave UV-B radiation from penetrating deeper into the leaves and, in the worst case, damage the plant DNA.
use
In analytical chemistry , in addition to α-cyano-4-hydroxycinnamic acid ( HCCA ) and 2,5-dihydroxybenzoic acid (DHB), it is used as an organic matrix substance in MALDI-MS (Matrix assisted laser desorption ionization mass spectrometry).
Individual evidence
- ↑ a b c d data sheet Sinapic acid from Sigma-Aldrich , accessed on April 23, 2011 ( PDF ).
- ↑ Data sheet sinapinic acid (PDF) from Carl Roth , accessed on February 19, 2010.
- ↑ Solubility of sinapic acid in non-aqueous solvents ( Memento of July 20, 2011 in the Internet Archive )
- ↑ Sinapic acid . In: Heinrich August Pierer , Julius Löbe (Hrsg.): Universal Lexicon of the Present and the Past . 4th edition. tape 16 . Altenburg 1863, p. 122 ( zeno.org ).
- ↑ Dissertation Genetic variation and inheritance of sinapic acid compounds in oilseed rape (Brassica napus L.) , Thomas zum Felde, University of Göttingen, 2005.
- ↑ Daniela Zeibig: UV radiation: Why plants don't get sunburn
- ↑ University of Bonn: mass spectrometry, interpretation aids ( memento from July 17, 2012 in the web archive archive.today ).
- ↑ Beavis, RC; Chait, BT: Cinnamic acid derivatives as matrices for ultraviolet laser desorption mass spectrometry of proteins , Rapid Commun. Mass Spectrom. , 1989 , 3 (12), pp. 432-435 ( PMID 2520223 ).