Barbara Zajc

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The possible role of bypass DNA polymerase zeta in mutagenic translesion synthesis past benzo[a]pyrene (BP) 7,8-diol-9,10-epoxide (DE) N(2)-deoxyguanosine (dG) adducts has been examined. We prepared 59-mer DNA templates containing dG adducts derived from trans opening of enantiomers of BP DE-2, in which the 7-hydroxyl group and epoxide oxygen are trans. The(More)
The postoligomerization method was used to prepare oligonucleotide 16-mers that contained dAdo or dGuo adducts, derived from trans opening of each enantiomer of the two diastereomeric benzo[a]pyrene 7,8-diol 9,10-epoxides, in two sequence contexts. These 16 oligonucleotides, along with the four corresponding oligonucleotides containing unsubstituted(More)
The potent environmental carcinogen benzo[a]pyrene (BaP), following enzymatic activation to enantiomeric pairs of bay-region 7,8-diol 9, 10-epoxides (the benzylic 7-hydroxyl group and epoxide oxygen are cis for DE-1 diastereomers and trans for DE-2 diastereomers), reacts with DNA to form covalent adducts predominately at the exocyclic amino groups of(More)
Site-specific mutagenicity of trans-opened adducts at the exocyclic N(2)-amino group of guanine by the (+)-(7R,8S,9S,10R)- and (-)-(7S,8R,9R,10S)-enantiomers of a benzo[a]pyrene 7,8-diol 9,10-epoxide (7-hydroxyl and epoxide oxygen are trans, BPDE-2) has been determined in Chinese hamster V79 cells and their repair-deficient counterpart, V-H1 cells. Four(More)
A straightforward access to protected 8-fluoro nucleosides via metalation-electrophilic fluorination under heterogeneous reaction conditions is reported. This is the first synthesis of 8-fluoro-2'-deoxyribonucleoside derivatives. Phenylsulfonyl substituted nucleosides are accompanying byproducts, possibly indicating a competing radical process. Higher(More)
Neither Sequenase 2.0 nor Klenow fragment were able to extend 12-mer primers using the eight templates (16-mers) derived by placing each of the four isomeric benzo[a]pyrene diol epoxide-deoxyguanosine adducts at the 13th nucleotide from the 3'-end of two different sequence contexts. Using an 11-mer primer to get a running start did not overcome the adduct(More)
Synthesis and reactivity of N-methoxy-N-methyl-(1,3-benzothiazol-2-ylsulfonyl)fluoroacetamide, a building block for Julia olefination, is reported. This reagent undergoes condensation reactions with aldehydes and cyclic ketones to give alpha-fluorovinyl Weinreb amides. Olefination reactions proceed under mild, DBU-mediated conditions, or in the presence of(More)
Julia-Kocienski olefination reagents 1-fluoropropyl, (cyclopropyl)fluoromethyl, 1-fluoro-2-methyl-2-propenyl, and 1-fluoro-5-hexenyl 1-phenyl-1H-tetrazol-5-yl (PT) sulfones were prepared by metalation followed by electrophilic fluorination. Although metalation-fluorination of n-propyl, 5-hexenyl, and (cyclopropyl)methyl PT-sulfones proceeded under(More)
Novel achiral and chiral alkyl alpha-(1,3-benzothiazol-2-ylsulfonyl)-alpha-fluoroacetates can be readily synthesized by metalation-fluorination of (1,3-benzothiazol-2-ylsulfonyl)acetates. DBU-mediated condensations of these fluorinated synthons with aldehydes proceed in a facile manner at 0 degrees C or at room temperature giving high yields of alpha-fluoro(More)