Hydrogen isotope labeling of α-hederin and a mass-spectrometric study of deuterium distribution

Deuterium-labeled α-hederin was prepared. Under the chosen conditions, 0.45-0.50 deuterium atom, on the average, is incorporated in the α-hederin molecule. The deuterium distribution was determined by mass spectrometry. The ratio between the deuterium contents in the disaccharide residue of the α-hederin molecule and in its steroid moiety is about 3: 1. The latter fact indicates that the double bond in the streoid moiety of α-hederin in the case of using a solid-phase labeling procedue is inaccessible to activated species of hydrogen isotopes. When performing isotope exchange in a gaseous tritium atmosphere, the molar radioactivity of the preparation reached 10 Ci mmol-1. © 2009 Pleiades Publishing, Ltd.