Caffeic acid
- 3,4- dihydroxycinnamic
- Trans-3- ( 3,4-dihydroxy- phenyl) propenoic
Yellow solid
Fixed
234-237 ° C ( decomposition)
Poorly in water
Attention
Template: Infobox chemical / molecular formula search available
The caffeic acid, 3,4- dihydroxycinnamic (English caffeic acid), belongs to the group of hydroxycinnamic acids and thus to the phenolic acids. Caffeic acid is next to the ferulic acid - a methyl ether of caffeic acid and a hydroxycinnamic acid - the most abundant phytochemical in food of vegetable origin. Coffee contains relatively high amounts of caffeic acid. Approximately 25-75 mg of caffeic acid are contained in a cup of coffee.
Properties
For caffeic acid has an inhibitory effect on the formation of induced stomach cancer was found in animal studies, where they also as an inhibitor in the endogenous formation of nitrosamines in humans plays an essential role.
However, studies on the carcinogenicity of caffeic acid led to ambivalent results. Some studies have shown anti-cancer, others, however, a cancer-promoting effect. Oral administration of high doses of caffeic acid in rats resulted in papillomas in the abdomen. However, the same study also showed that high-dose combined doses of antioxidants, including caffeic acid, in the same rats resulted in a significant decline in growth of intestinal tumors. Other significant effects were not detected. Caffeic acid is fed carcinogenic in some hazardous material data sheets as potentially, for example, on the list of IARC as a group 2B carcinogen ( "possibly carcinogenic to humans" ). More recent data indicate that in the rat intestinal bacteria affect the formation of metabolites of the caffeic acid, however, when people have such disease -promoting effects are known.
Applications
In addition to medical applications caffeic acid acts as an evolving substance in alternate black and white developers (see Caffenol ). It is used, inter alia, in combination with vitamin C (ascorbic acid ) to reduce the exposed silver halide to metallic silver.