... chemistry, protein nitrogen heterocyclic indene, inspection of three phenol and tannin acid.In the pharmaceutical industry, for the production ... of antihypertensive drug methyldopa, catechol drug L-dopa, and Katalin, diaveridine etc.. 20kg, 50kg/fiber board drums; ... s production, the company has created a perfect industry chain,and the product line includes vanillin,ethyl vanillin,guaiacol,o ...