Rosmarinic acid

• (S, R) -3 - ( 3,4-dihydroxy -phenyl) -acrylic acid 1 -carboxy- 2-( 3,4- dihydroxy- phenyl)- ethyl
• 2-O- caffeoyl -2-hydroxy -2 ,3- dihydrokaffeesäure

Dark red solid with a characteristic odor

Fixed

0.91 g · cm -3

~ 170 ° C

Something in the water

Template: Infobox chemical / molecular formula search available

Rosmarinic acid is the trivial name of the plant kingdom widespread phenylacrylic. Chemically, it is the ester of caffeic acid with 3 - ( 3,4- dihydroxyphenyl ) lactic acid.

• 5.1 reaction of L -phenylalanine, 4 - coumaroyl -CoA
• Reaction of L- tyrosine 5.2 to 4 Hydroxyphenyllactat
• 5.3 Implementation of 4- coumaroyl -CoA with 4- Hydroxyphenyllactat and final hydroxylation

History

The first isolation and characterization of rosmarinic acid was carried out in 1958. It was won this year by the two Italian chemists ML Scarpatti and G. Oriente from rosemary (Rosmarinus officinalis).

Occurrence

Especially the families of Lamiaceae, especially the subfamilies Nepetoideae and Boraginaceaen are rich in rosmarinic acid. However, it can also be found in taxonomically further remove groups of plants, such as ferns and hornworts, but here in a lower concentration.

Use

Use in the pharmaceutical industry

Rosmarinic acid has anti-viral, antibacterial and anti-inflammatory properties. It is therefore in different balm preparations used (eg Lomaherpan ® cream), as well as in some ointments for sports injuries (eg trauma Plant ® ).

Pure rosmarinic acid acts against the complement-dependent stimulation of prostaglandin synthesis, has antioxidant properties, blocks the opsonization and can be easily absorbed through the skin.

Others use

Rosmarinic acid has, like many other phenolic carboxylic acid ester, tanning properties. Since they mainly occur in plant species of the Lamiaceae family, it is also called Lamiaceengerbstoff or as Labiatengerbstoff - called - Labiatae is the obsolete term for mint. In animal experiments they had chemoprotective, neuroprotective and potentially antidepressant effects.

Biological Significance

Rosmarinic acid is a secondary plant substance. Plants synthesize it as a defense agent against fungi and bacteria. It is also suspected that it protects the plant against herbivores. Plants store rosmarinic acid in the vacuoles isolated from oxidases. If there is an injury, this compartmentalization is canceled. The phenolic hydroxyl groups of rosmarinic acid are oxidized to Orthochinonen. These peptides bind to and inactivate it by.

Biosynthesis

The biosynthesis of rosmarinic acid was investigated in 1970 in more detail. It starts with the two amino acids L- phenylalanine and L- tyrosine. It involved a total of eight different proteins in it. The biosynthesis can be divided into three different processes are divided:

Reaction of L -phenylalanine, 4 - coumaroyl -CoA

In the first step phenylalanine using the phenylalanine ammonia lyase (PAL) is deaminated to E- cinnamic acid. This reaction can be observed in many biosynthesis of compounds with phenylpropanoid backbones. Thus, the synthesis of lignins, flavonoids and coumarins beginning this step.

In a second step, a hydroxyl group is introduced into the aromatic ring of the E- cinnamic acid. This hydroxylation is the enzyme cinnamate -4- hydroxylase catalyzes ( CAH ), 4- coumaric acid is produced. The latter forms as well as part of the deamination of the amino acid L- tyrosine with PAL, as this enzyme can also use this amino acid as the substrate.

The third and final step of this general phenylpropanoid the 4- coumarate -CoA ligase ( 4CL ) converts the 4- coumaric acid to the corresponding CoA esters.

Reaction of L- tyrosine 4- Hydroxyphenyllactat

Parallel to the reaction of L-phenylalanine, the reaction of L- tyrosine. In the first step, the tyrosine aminotransferase (TAT ) catalyzes the transamination of 2 -oxoglutarate as an amino acceptor to 4 -hydroxyphenylpyruvate, and glutamate. In the second step, the pyruvate is the NADH / NADPH-dependent hydroxyphenylpyruvate reductase ( HPPR ) to R ( )-4- Hydroxyphenyllactat reduced.

Reaction of 4- coumaroyl -CoA with 4- Hydroxyphenyllactat and final hydroxylation

The lactate is the rosmarinic acid synthase ( RAS) on the aliphatic hydroxy group esterified with the formed in the first step, 4- coumaryl -CoA to 4- coumaroyl -4'- Hydroxyphenyllactat. This ester is hydroxylated in two stages in the positions 3 and 3 ' on the aromatic rings. These reactions are catalyzed by two membrane-bound cytochrome P450-dependent hydroxylases. This first intermediate result caffeoyl -4'- Hydroxyphenyllactat or 4 - coumaroyl 3 ', 4'- Dihydroxyphenyllactat and finally the rosmarinic acid.