Antivitamins B₁₂ -Some Inaugural Milestones

The recently delineated structure- and reactivity-based concept of antivitamins B₁₂ has begun to bear fruit by the generation, and study, of a range of such B₁₂ -dummies, either vitamin B₁₂ -derived, or transition metal analogues that also represent potential antivitamins B₁₂ or specific B₁₂ -antimetabolites. As reviewed here, this has opened up new research avenues in organometallic B₁₂ -chemistry and bioinorganic coordination chemistry. Exploratory studies with antivitamins B₁₂ have, furthermore, revealed some of their potential, as pharmacologically interesting compounds, for inducing B₁₂ -deficiency in a range of organisms, from hospital resistant bacteria to laboratory mice. The derived capacity of antivitamins B₁₂ to induce functional B₁₂ -deficiency in mammalian cells and organs also suggest their valuable potential as growth inhibitors of cancerous human and animal cells.