title: [Riboflavin-radical formation by mechanochemical solid-state reaction using stainless steel vessel].
abstract: The mechanochemical reaction of free riboflavin (FR) due to vibratory ball milling was carried out in a stainless steel vessel at room temperature under anaerobic conditions. The ESR of the fractured sample showed a broad single-line spectrum. It is suggested that the solid-state single-electron transfer (SSET) reaction from the surface of the stainless steel vessel to FR proceeded during the vibratory milling, resulting in the formation of the corresponding anion radicals. When the mechanochemical reaction of FR in the presence of calcium pantothenate (PC) was carried out, the radical concentration increased with the increasing PC content. It was shown that the anion radical in the metal complex was stable for a lengthy period of time even in highly humid air.
authors.affiliation: Laboratory of Pharmaceutical Physical Chemistry, Gifu Pharmaceutical University, 5-6-1 Mitahora-Higashi, Gifu 502-8585, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kondo
authors.forename: Youji
authors.initials: Y
authors.lastname: Furuta
authors.forename: Shintarou
authors.initials: S
authors.lastname: Okita
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sasai
authors.forename: Hideki
authors.initials: H
authors.lastname: Aramaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kuzuya
mesh_terms: D000838:Anions; D002626:Chemistry, Pharmaceutical / Q000295:instrumentation*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D006813:Humidity; D010205:Pantothenic Acid; D012256:Riboflavin / Q000737:chemistry*; D013193:Stainless Steel; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D000838:Anions; D005609:Free Radicals; D013193:Stainless Steel; D010205:Pantothenic Acid; D012256:Riboflavin