title: Biological significance of the electronic structure of alloxan and its tautomers.
abstract: By means of a molecular orbital method which considers all valence electrons, INDO, we have calculated several electronic indices and determined the major tautomers in the lactan-lactim tautomerism of alloxan in the liquid and gaseous states. We have found that the principal tautomer, in both the gas phase and in solution, is the keto form; however, in solution, we have found a major contribution by the 2-hydroxy form. In addition, we have determined that the most reactive group, in all tautomers, to nucleophilic addition is the 5-CO group. We also made some observations concerning the effect of the electronic structure of alloxan on its diabetogenic activity.
mesh_terms: D000496:Alloxan / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D005740:Gases; D011789:Quantum Theory; D012996:Solutions; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D005740:Gases; D012996:Solutions; D000496:Alloxan