3,4-Dihydroxybenzoic acid monohydrate, 98% [99-50-3] (Protocatechuic acid monohydrate) C7H6O4H2O MW 154.3 + H2O Merck Index 11,7909 Pale gray or pale brown fine powder Assay: not less than 98.5% (anhydrous basis) 中文名称:3,4-二羟基苯甲酸中文同义词:3,4-二羟基苯甲酸;原儿茶酸;原儿茶酸(