Chelation mimosine

The condensation of 3,4-HP with deoxyribonucleotide results in a unique metal-binding nucleotide (55) which can be incorporated into an oligonucleotide chain. This ohgonu-cleotide has higher thermostability in the presence of Cu(II) compared with an A-T pair, wherein Cu(II) binds to 3,4-HP from each strand to form a double helix (56). li en the Fe(II)-mimosine complex is introduced to plasmid DNA, cleavage of the supercoiled form is observed in the presence of H2O2 and dithiothreitol. The observations described in this section point to mimosine (9) and its analogues as the leads for further exploration of their potential application as metal chelators and therapeutics. 

There are several others that inhibit DNA replication. Fagaronine and nitidine have ben mentioned previously as intercalating agents, and this intercalation evidently inhibits the action of DNA polymerase [334]. Several benzophenanthridines and protoberberines inhibit reverse transcriptase, which catalyzes the synthesis of DNA with an RNA template [356, 357]. Mimosine at the cellular level, rather than directly on the process, is an inhibitor of DNA synthesis because it chelates iron [358] and because it blocks the synthesis of thymidylate, an essential precursor of DNA [359]. Vincristine may also act as an inhibitor of thymidylate synthesis, perhaps because it alkylates an essential thiol group of an enzyme [360]. 

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