Chemical synthesis and detection of the cross-link 1-[N3-(2'-deoxycytidyl)]-2-[N1-(2'-deoxyguanosinyl)]ethane in DNA reacted with 1-(2-chloroethyl)-1-nitrosourea.
We have synthesized 1-[N3-(2'-deoxycytidyl)]-2-[N1-(2'-deoxyguanosinyl)]ethane and confirmed its structure by ultraviolet and high-resolution mass spectrometry. Treatment of calf thymus DNA with [3H](2-chloroethyl)-1-nitrosourea resulted in the formation of at least 13 DNA alkylation products that were separated by HPLC. 1-[N3-(2'-Deoxycytidyl)]-2-[N1-(2'-deoxyguanosinyl)]ethane was a minor product, accounting for 3.4% of the total DNA alkylation. The DNA cross-link 1,2-di-N7-guanylethane was formed to a similar extent (3.2%). Other minor alkylation products were O6-(2-hydroxyethyl)deoxyguanosine (1.5%) and N1-(2-hydroxyethyl)deoxyguanosine (3.8%). The principal alkylation products formed by 1-(2-chloroethyl)-1-nitrosourea (CNU) treatment of DNA were N7-(2-hydroxyethyl)guanine (36.4%), N7-(2-chloroethyl)guanine (14.6%), and phosphotriesters (26.1%). The development of analytical procedures to measure DNA alkylation products after treatment with CNU will allow us to investigate factors influencing their formation and repair.
Bodell
W J
WJ
Brain Tumor Research Center, School of Medicine, University of California, San Francisco 94143.
Pongracz
K
K
D000478:Alkylation; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents; D004247:DNA / Q000032:analysis* / Q000187:drug effects; D003853:Deoxyribonucleosides / Q000032:analysis / Q000138:chemical synthesis* / Q000302:isolation & purification; D005038:Ethylnitrosourea / Q000031:analogs & derivatives* / Q000494:pharmacology; D013058:Mass Spectrometry; D013056:Spectrophotometry, Ultraviolet
D003432:Cross-Linking Reagents; D003853:Deoxyribonucleosides; C017139:1-(2-chloroethyl)-1-nitrosourea; C035421:1-(N(3)-deoxycytidyl)-2-(N(1)-deoxyguanosinyl)ethane; D004247:DNA; D005038:Ethylnitrosourea