3,4-dihydroxybenzoic acid is a complex and multi-classification metabolite of anthocyanins and proanthocyanins. It has antioxidant, antibacterial and anti-inflammatory effects and is often used in medical treatment, feed, daily chemical products and other fields.

The main extraction methods of 3,4-dihydroxybenzoic acid are as follows: one is from thistle and the other is from lilac leaf. What are the differences between the two? Let’s take a look at the simple acceptance of xiaobian!

Extract 3,4-dihydroxybenzoic acid from the artichoke, which needs to take the artichoke raw medicine as the raw material, boil it in water for half an hour, then combine the water solution twice, filter it out and drop the filter residue in order to get coffee-colored filtrate, then use electric furnace to heat and concentrate, and then add ethyl acetate for extraction after cooling, and retain the lipid layer. Water layer can be used to extract caffeic acid, brass. Decompression, concentrated lipid layer until the dry state, is extracted with hot water, the suction filter, discarded, and water will not mix of precipitation, the water fluid acidification, ether, give water, retain the ether layer, with a concentration of 5% sodium bicarbonate solution is extracted in the ether layer, give the ether layer, will retain the extracted liquid with sodium bicarbonate acidification, ether, and PH adjustment to 6, 3,4-dihydroxybenzoic acid can be obtained by concentrated crystallization and recrystallization with CHCl3.

During the extraction of 3,4-dihydroxybenzoic acid from the leaves of syringa syringa, the dried original medicinal materials of syringa syringa leaves with seeds and sundries removed were selected, and the subdivided powder of syringa syringa leaves could be obtained by crushing. It was used as raw material, and anhydrous ethanol was used as the extraction agent under the set process conditions. We need to extract for filtration, discard liquid, the recovery of ethanol, can get protocatechuic acid crude products, crude products protocatechuic acid and ether and hydrochloric acid, vibration dissolve, and inserted in the separatory funnel, again using naoh solution for extraction, extraction of three times, using ether washing again, adding hydrochloric acid, combination of sodium hydroxide solution, then using ether extract three times, Wash with water in the ether layer, combine to get ether solution, adjust the PH value to the neutral state, steam dry, can get white powder crystal 3,4-dihydroxybenzoic acid.