Organic acid anhydride Organic acid anhydride An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride being (RC(O))O. Symmetrical acid anhydrides of this type are named by replacing the word "acid" in the name of the parent carboxylic acid by the word "anhydride". Thus, (CHCO)O is called "acetic anhydride." Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride
Syringic acid in vinegar. Syringic acid can be enzymatically polymerised. Laccase and peroxidase induced the polymerization of syringic acid to give a poly(1,4-phenylene oxide) bearing a carboxylic acid at one end and a phenolic hydroxyl group at the other. Syringic acid Syringic acid is a naturally occurring "O"-methylated trihydroxybenzoic acid, a type of chemical compound. Syringic acid can be found in "Ardisia elliptica". Syringic acid can be prepared by selectively hydrolyzing (demethylating) eudesmic acid with 20% sulfuric acid. Syringic acid can be found in the açaí palm ("Euterpe oleracea") and its oil (1,073 ± 62 mg/kg). It is also present in wine.