Caractérisation de la l-thréo-β-hydroxyleucine à partir de Deutzia gracilis

l-threo-β-Hydroxyleucine has been isolated from Deutzia gracilis by ion-exchange resin chromatography, and by preparative paper chromatography. The substance is reduced to leucine by hydroiodic acid and offers the characteristic reaction of β-hydroxyamino acids with periodic acid. Alkaline decomposition confirms the β position of the alcohol function. The natural substance and the dl-threo-β-hydroxyleucine are inseparable by paper chromatography, and the study of their nuclear-magnetic-resonance spectra brings supplementary arguments in favour of the threo form. The natural substance has the same infrared spectrum as synthetic threo-β-hydroxyleucine.