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-[PtCI(NH 3)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. © Schweizerische Chemische Gesellschaft.