Fast repair of dAMP radical anions by phenylpropanoid glycosides and theiranalogs

Repair effect on 2'-deoxyadenosine-5'-monophosphate (dAMP) radical anions b y phenylpropanoid glycosides (PPGs) and their analogs, isolated from Chines e folk medicinal herb, was studied using pulse radiolysis technique. The ra dical anion of dAMP was formed by the reaction of hydrated electron with dA MP. On pulse irradiation of nitrogen-saturated dAMP aqueous solution contai ning 0.2 M t-BuOH and one of PPGs or their analogs, the transient absorptio n spectrum of the radical anion of dAMP decayed with the formation of that of the radical anion of PPGs or their analogs within several decades of mic roseconds after electron pulse irradiation. The results indicated that dAMP radical anions can be repaired by PPGs or their analogs. The rate constant s of the repair reactions were deduced to be 1.6-4.5 X 10(8) M-1 s(-1). (C) 2000 Elsevier Science B.V. All rights reserved.