Cytarabine conjugates with biologically active molecules and their potential anticancer activity.

The presented review article deals with various conjugates of arabinosylcytosine (araC). This powerful drug that is routinely used in therapy of hematological malignancies has some shortcomings, which limit its use and therapeutic effects. These are low lipophilicity, low stability to degrading enzymes and need for biological activation through phosphorylation. Conjugating araC to another molecule is done with the intention of increasing araC stability and lipophilicity and possibly avoiding rate-limiting araC phosphorylation. An attachment of that another molecule, possessing its own biological activity, may result in formation of a conjugated molecule with new biological activities and better therapeutic potential. The review deals with various araC conjugates formed at the positions N(4), 2, 2', 3' and 5'. Biological activities and differences from araC of compounds formed by conjugation are also discussed.