Chalcogen Bonds in Selenocysteine Seleninic Acid, a Functional GPx Constituent, and in Other Seleninic or Sulfinic Acid Derivatives

The controlled oxidation reaction of L-selenocystine under neutral pH conditions affords selenocysteine seleninic acid (3-selenino-L-alanine) which is characterized also by means single-crystal X-ray diffraction. This technique shows that selenium forms three chalcogen bonds (ChBs), one them being outstandingly short. A survey derivatives in the Cambridge Structural Database (CSD) confirms C?Se(=O)O? functionality tends to act as a ChB donor robust enough systematically influence interactional landscape solid. Quantum Theory Atom Molecules (QTAIM) analysis proves attractive nature short contacts observed crystals containing and calculation surface molecular electrostatic potential (MEP) reveals remarkably positive ?-holes can frequently be found opposite covalent at selenium. Both CSD searches QTAIM MEP approaches show sulfinic moiety function donor, albeit less than one. These findings may contribute better understanding, atomic level, mechanism action enzymes control oxidative stress ROS deactivation contain cysteine active site.