The Structural Identification and Conformational Analysis of the Products from the Reaction of Acrolein with 2′-Deoxycytidine, 1-Methylcytosine and Calf Thymus DNA

LC‐MS analysis of the reaction mixture of 2′‐deoxycytidine and acrolein in phosphate buffer under physiological conditions showed the formation of three major product peaks. The products were characterized as cyclic adducts comprised of one or two units derived from acrolein. The first (8) and third (9) eluting peaks were each found to be a pair of diastereomers of a two‐ring‐fused adduct, 6,9‐dihydroxy‐2‐(2′‐deoxy‐β‐D‐erythro‐pentofuranosyl)‐2,5,6,7,8,9‐hexahydro‐4H‐2,3a,6a‐triazaphenalen‐3‐one, whilst the second eluting peak (7) was identified as a one‐ring‐fused adduct, 2‐hydroxy‐7‐(2′‐deoxy‐β‐D‐erythro‐pentofuranosyl)‐2,3,4,7‐tetrahydropyrimido[1,6‐a]pyrimidin‐6‐one. The reaction of 1‐methylcytosine with acrolein was also examined resulting in the formation of an additional regioisomeric two‐ring‐fused adduct, 2‐hydroxy‐7‐methyl‐3,4,7,9,10,10a‐hexahydro‐2H‐1‐oxa‐4a,7,8a‐triazaphenanthren‐8‐one, not observed in the corresponding reaction with 2′‐deoxycytidine. The structures, stereochemistry and conformational analysis of the adducts and their decomposition products were resolved by spectrometric and spectroscopic studies. From the incubation of acrolein with double‐ and single‐stranded DNA and subsequent LC‐MS/MS analysis (in multiple reaction monitoring mode) of the hydrolysate, compounds were detected corresponding (i.e. identical Rt and MS) to the peaks that represented the pair of diastereomers 7 and 9.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)