Caffeic acid is an organic acid with a molecular formula of C9H8O4 and a relative molecular weight of 180. Different preparation methods lead to different caffeic acid. Generally speaking, the yellow crystal of caffeic acid is obtained from a concentrated aqueous solution, while the monohydrate is obtained from a dilute aqueous solution, and the decomposition point is 223℃-225℃, during which the softening occurs at 194℃. Slightly soluble in cold water, easily soluble in hot water and cold ethanol.
The safety of caffeic acid is relatively high, can be used in the field of cosmetics, its bacteriostatic and antiviral activity is wide, can absorb ultraviolet light, low concentrations of caffeic acid can also be used as hair dye additives, and mainly play a role in enhancing color intensity, in addition, caffeic acid can also be used as an organic intermediate for organic synthesis.
Caffeic acid synthesis methods basically have two kinds, one is single ear bugbane rhizome with methanol extraction, vacuum concentration to remove methanol, dissolve the residues in hot water, hot leach insoluble, wait for after cooling extraction with benzene, benzene solution with 1% sodium bicarbonate solution washing, collect lotion, plus dilute hydrochloric acid acidification, with benzene organic acid was isolated, reduced pressure concentration removal of benzene, The residue is caffeic acid enriched product. On the other hand, caffeic acid can be obtained by acid hydrolysis of chlorogenic acid as raw material.