Zur Chemie des Biotins. Nachweis eines Harnstoffrings. 28. Mitteilung über pflanzliche Wachstumsstoffe

Abstract

The crude oil containing the biotin methyl ester was prepared from 1650 kg. hen''s egg yolks as previously descr. (Hoppe-Seyler''s Zeitschr. physiol. Chem., 242: 43, 1936), and was subjected to mol. distill., the methyl ester distilling at 150[degree]-155[degree]. When recrystallized from mesityl oxide, the ester melted at 158[degree], had a probable mol. wt. of 258, and a biol. activity of 25[center dot]109 units/g. Various of its physical and chemical properties and reactions are described. Two of the O atoms of biotin are in the carboxyl group, the 3d O atom is in a urea ring grouping, and biotin may be regarded as a derivative of trimethylene urea. Biotin is believed to contain 2 rings, the S being present in a thio ether group.