Nechev L V, Kozekov I, Harris C M, Harris T M
Department of Chemistry and Center in Molecular Toxicology, Vanderbilt University, Nashville, TN 37235, USA.
Chem Res Toxicol. 2001 Nov;14(11):1506-12. doi: 10.1021/tx0100690.
Crotonaldehyde reacts with DNA to form two diastereomeric 1,N(2) cyclic adducts of deoxyguanosine. A synthesis of the two diastereomeric deoxynucleosides has been achieved by reaction of mixed diastereomers of 4-amino-1,2-pentanediol with 2-fluoro-O(6)-(trimethylsilylethyl)-deoxyinosine. The resulting N(2)-(1-methyl-3,4-dihydroxybutyl)-deoxyguanosine was treated with NaIO(4), cleaving the vicinal diol to the aldehyde. Spontaneous cyclization gave the two diastereomers of the crotonaldehyde-adducted nucleoside that were readily separated by HPLC. The absolute configurations were assigned by an enantiospecific synthesis of one diastereomer from (S)-3-aminobutanoic acid. The synthetic strategy has been extended to preparation of a site-specifically adducted oligonucleotide by reaction of the mixed diastereomers of 4-amino-1,2-pentanediol with an 8-mer oligonucleotide containing 2-fluoro-O(6)-(trimethylsilylethyl)-deoxyinosine. The diastereomeric oligonucleotides were separated by HPLC and absolute configurations of the adducts were established by enzymatic digestion to the adducted nucleosides.
巴豆醛与DNA反应形成两种非对映异构的脱氧鸟苷1,N(2)环加合物。通过4-氨基-1,2-戊二醇的混合非对映异构体与2-氟-O(6)-(三甲基硅乙基)-脱氧肌苷反应，实现了两种非对映异构脱氧核苷的合成。将所得的N(2)-(1-甲基-3,4-二羟基丁基)-脱氧鸟苷用高碘酸钠处理，将邻二醇裂解为醛。自发环化产生了巴豆醛加合核苷的两种非对映异构体，它们很容易通过高效液相色谱法分离。通过由(S)-3-氨基丁酸对一种非对映异构体进行对映体特异性合成来确定绝对构型。通过4-氨基-1,2-戊二醇的混合非对映异构体与含有2-氟-O(6)-(三甲基硅乙基)-脱氧肌苷的8聚体寡核苷酸反应，将合成策略扩展到制备位点特异性加合的寡核苷酸。通过高效液相色谱法分离非对映异构寡核苷酸，并通过酶促消化为加合核苷来确定加合物的绝对构型。
