Labelling of antibiotic peptide - edeine B with 14C

Edeine B with guanyl group labelled with 14C was obtained by treating edeine A with a 6-fold excess of O-methylisourea-14C. The radiochemical yield was 10, 1%. The product was purified on a column, filled with Sephadex LH 20 and by preparative paper chromatography. The radiochemical purity of the obtained preparation was 97.7%.