Formation of malonaldehyde and acetaldehyde from the oxidation of 2 '-deoxyribonucleosides

2'-Deoxyribonucleosides, ribonucleosides, nucleobases, deoxyribose, and rib ose were oxidized with Fenton's reagent. Malonaldehyde (MA) formed was deri vatized with N-methylhydrazine to N-methylpyrazole, and acetaldehyde formed was derivatized with cysteamine to 2-methylthiazolidine. The resulting nit rogen-containing derivatives were quantitatively analyzed using gas chromat ography with a nitrogen-phosphorus detector. MA and acetaldehyde were found in 2-deoxy-D-ribose and 2'-deoxyribonucleosides but not in ribonucleosides , nucleobases, and D-ribose. Amounts of MA formed from four deoxynucleoside s were in the following order: 2'-deoxyguanosine > 8'-deoxycytidine > 8'-de oxyadenosine greater than or equal to thymidine. Amounts of acetaldehyde fo rmed from four deoxynucleosides were in the following order: 2'-deoxycytidi ne > thymidine > 2'-deoxyadenosine greater than or equal to 2'-deoxyguanosi ne. The results suggest that the formation of MA and acetaldehyde requires a deoxy group on carbon 2' of a ribose moiety.