Amino Acid Derivatives of Kojic Acid

Metal coordination and tyrosinase inhibition studies with Kojic-βAla-Kojic

“…These studies mainly investigated the ability of the synthesized kojic acid derivatives to improve inhibitory properties by converting the methylene hydroxyl group into ester [15], hydroxylphenyl ester [16], glycoside [17] and amino acid derivatives [18][19][20][21].…”

The first synthesis of 3‐hydroxy‐2‐(polyfluoroalkyl)chromones and their ammonium salts. 3‐hydroxychromone in the Mannich reaction

“…Very recently [20], it has been shown that 3‐formylchromones react with α‐aminoacids in the presence of excess formaldehyde to produce N ‐(chromone‐3‐ylmethyl)‐α‐aminoacids by a deformylative Mannich type reaction. It was also observed that α‐aminoacids can be used as the amine component in a Mannich reaction with kojic acid [21]. However, the use of 3‐hydroxychromones in this reaction has not been reported in the literature.…”

Kojic acid in organic synthesis

“…Aytemir et al Reaction of KA with methylamine, followed by treatment with formaldehyde (37% aqueous solution) and piperidine under reflux conditions in EtOH for 24 h under a Mannich reaction gave 3-hydroxy-6-hydroxymethyll-methyl-2-piperidinomethyl-4(lH)-pyridinone 70 in 47% yield (Scheme 24), which acts as a bidentate ligand with high affinity for metal ions in high oxidation state. A Mannich-type reaction of KA with amino acids and formaldehyde was reported by O'Brien et al; 81 it is not as simple as the reaction with other types of amines because of variations in the structure and solubility characteristics of amino acids. The reaction of KA with several amino acids was carried out in the presence of 37% formaldehyde in water/EtOH.…”