Preparative counter-current chromatography purification of valrubicin (AD-32) from crude synthetic drug using upright coil planet centrifuge with four multilayer coils connected in series

Preparative counter-current chromatography (CCC) purification of valrubicin (AD-32) from crude synthetic drug has been successfully performed for the first time using upright coil planet centrifuge with four multilayer coils connected in series with 1600 ml capacity. The two-phase system used was composed of light petroleum (bp 60–90 °C)–ethyl acetate–tetrachloromethane–methanol–water at an optimized volume ratio of 1:1:8:6:1. Target compound (1.2 g) with a purity of 99.88% was obtained from 1.5 g of crude synthetic drug with a purity 95.49% based on HPLC peak area percentage. Identification of the target compound was performed by electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance.