Parietin

• Physcion
• Rheochrysidin
• Emodin -3- methyl

Risk

Template: Infobox chemical / molecular formula search available

Parietin is a dye from the group of anthraquinones.

Occurrence

The natural product is found in various lichens, including lichens of the genus Caloplaca and the Ordinary Gelbflechte. He is there extracellularly in the thallus available. The biosynthesis of this substance is operated by the non- photosynthetic partner in the lichen, so the fungus.

Description

The yellow, soluble in acetone substance is a derivative of anthraquinone. It reacts with potassium hydroxide or ammonia water purple. With baryta or lime water to form insoluble salts violet.

Use

Basic properties of this secondary plant substance were already in the 18th century known and have been described by Rémi Willemet. He notes that gained residents Ölands from a lichen of the genus Parmelia using alum yellow dye for coloring wool, and the braid itself was eaten by goats. According to Hermann Hoffmann was also cooked in milk as a remedy for jaundice.

Function

The concentration of the dye in the lichen is higher when it is more exposed to the light, that is higher on a sunny rock as on a shady tree, and higher in summer than in winter.

In a protective effect against UV-induced cell damage, as well as a reduction in the biological function of photoinhibition substance is seen. Your metabolism is not yet fully explored. The model applies the biosynthesis of orsellinic, ie by cyclization of polyketides.