Protocatechuic acid, PCA molecule. It is 3,4-dihydroxybenzoic, phenolic acid, metabolite of antioxidant polyphenols, catechol, is found in green tea. Dark blue background. Vector illustration

Potassium acid (Potassium acid, Potassium acid, Potassium acid, Potassium acid, Potassium acid, Potassium acid) molecule. Structural chemical formula on the dark blue background. Vector illustration