Nucleic acid notation Nucleic acid notation The nucleic acid notation currently in use was first formalized by the International Union of Pure and Applied Chemistry (IUPAC) in 1970. This universally accepted notation uses the Roman characters G, C, A, and T, to represent the four nucleotides commonly found in deoxyribonucleic acids (DNA). Given the rapidly expanding role for genetic sequencing, synthesis, and analysis in biology, researchers have been compelled to develop alternate notations to further support the analysis and manipulation of genetic data. These notations generally exploit size, shape, and symmetry to accomplish these objectives. Degenerate base symbols in biochemistry are an IUPAC
Prephenic acid higher priority (according to CIP rules) on the two pseudoasymmetric carbons, "i.e." the carboxyl and the hydroxyl groups, in the "cis" configuration, or (1"s", 4"s") according to the new IUPAC stereochemistry rules (2013). The other stereoisomer, "i.e. trans" or, better, (1"r", 4"r"), is called epiprephenic. Prephenic acid Prephenic acid, commonly also known by its anionic form prephenate, is an intermediate in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine, as well as of a large number of secondary metabolites of the shikimate pathway. It is biosynthesized by a [3,3]-sigmatropic Claisen rearrangement of chorismate. Prephenic acid is an example