Syntheses of Fluorescent Vitamin B12-Pt(II) Conjugates and their Pt(II) Release in a Spectroelectrochemical Assay

Abstract

The cisplatin adduct of vitamin B12, cis-[PtCl(NH3)2B12]+ (1) reacts with dansyl-imidazole to form cis-[Pt(dansyl-imidazole)(NH3)2B12] (2). In a spectroelectrochemical assay, Co(III) in 2 was reduced to Co(II) under concomitant release of the Pt(II) complex. Since similar reduction occurs in the intracellular space, 2 can be used for studying cell uptake monitored by fluorescent microscopy. The insertion of a fluorescent marker into the platinum moiety will also facilitate the isolation of the platinum complex released from B12 and therefore to characterize its chemical authenticity.