Role of sugar in controlling reaction pattern: A comparative study with adenine and 2′-deoxyadenosine

Interaction between 2-methyl-1,4-naphthoquinone (MQ) and adenine (A) and 2'-deoxyadenosine (dA) reveals interesting differences with respect to electron transfer (ET) and hydrogen abstraction (HA). In our case A and dA exhibited ET from different sites, which has been associated to the presence of a sugar unit in dA. Sugar unit has also reduced the rate of ET from dA. We have utilized an external magnetic field in conjunction with our laser flash photolysis set-up to establish our data. In a polar MeCN/H2O medium A and dA are found to promote ET but HA from dA is seen to be insignificant. However shifting to a heterogeneous micellar medium has been found to have a marked effect in increasing the HA rate for dA only. Separate experiments with 2'-deoxyribose sugar have revealed sugar moiety to be more susceptible to HA in SIDS medium. (c) 2008 Elsevier B.V. All rights reserved.