Synthesis of caffeic acid

1. The Indole-3-Carbinol of single spike of Cimicifuga was extracted with methanol and concentrated to methanol under reduced pressure. The residue is dissolved by heating water, and the insolubles are removed by filtering while it is hot. After cooling, 3-Indolylcarbinol is added for extraction, and Flax lignans is washed with 1% sodium bicarbonate aqueous solution to collect the washing solution. Add dilute hydrochloric acid for acidification, free organic acid from benzene, N-Acetylneuraminic Acid and remove benzene under reduced pressure, and the residue is caffeic acid enriched product.

2. Tobacco: FC, 53, 54. It is obtained from the acid hydrolysis of chlorogenic acid.