3,4-dihydroxybenzoic acid is an organic compound with antibacterial, antioxidant, antioxidant and other functions. It is also the metabolite of complex polyphenols such as anthocyanins and proanthocyanins, which is mainly used in medicine, daily chemicals, feed and other fields.
3,4-dihydroxybenzoic acid can be obtained from thistle or lilac leaves.
When the artichoke is used as the raw material to obtain 3,4-dihydroxybenzoic acid, it is necessary to add water to the raw artichoke and cook it for half an hour. The two decocted solutions are combined and then pumped to get coffee-colored filtrate. The filtrate is heated and concentrated in an electric furnace, and then ethyl acetate is added for extraction after cooling. Lipid layer to reduced pressure, concentration and drying, heat water again, the suction filter, remove the sediment, water solution to acidification, ether, get the ether layer is extracted with 5% sodium bicarbonate solution, after removing the ether layer after got the sodium bicarbonate extract, after sodium bicarbonate, ether extract acidification, adjust PH value to six, enrichment crystallization and recrystallization with CHCl3, Get 3,4-dihydroxybenzoic acid.
When we use the lilac leaves as raw materials to obtain 3,4-dihydroxybenzoic acid, we need to remove the seeds and other sundry materials from the lilac leaves to get clean and dry raw materials, and then grind it into fine powder. Under specific process conditions, anhydrous ethanol is used as the extraction agent, filtrate the extraction solution, remove the residue and recover the ethanol. The crude 3,4-dihydroxybenzoic acid is obtained, adding dihydroxybenzoic acid and hydrochloric acid, shaking to dissolve, placed in a separation funnel, extracting with sodium hydroxide, washing the ether layer with water, combining to get ether solution, adjust the PH value to neutral, after drying, 3,4-dihydroxybenzoic acid can be obtained.