Breaking action of reductones related to ascorbic acid on nucleic acids.

The action of two types of ascorbate-related reductones on nucleic acids was investigated by comparison with that of ascorbic acid (AsA). Amino reductone (ScA) and thiol reductone (MHC) caused strandscissions in nucleic acids. This was confirmed by the fact that reductones lowered the viscosity of DNA solution and shifted the peaks of DNA and RNA to the low molecular side in centrifugal profile. Cu2+ strengthened their action as in the case of enediol reductones. The braking activity of thiol reductone is relatively wesk compared with those of amino and enediol reductones. The preferential degradation of spurinic acid was caused with amino and thiol reductones, suggesting that pyrimidine clusters in nucleic acids were susceptible to breakage.