Synthesis and Reactivity of Aryl Nitrogen Mustard−Oligodeoxyribonucleotide Conjugates

• Published in: Bioconjugate chemistry Vol. 9; no. 1; pp. 64 - 71
• Main Authors: Reed, Michael W, Lukhtanov, Eugeny A, Gorn, Vladimir, Kutyavin, Igor, Gall, Alexander, Wald, Ansel, Meyer, Rich B
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01-01-1998
• Subjects: Alkylation; Base Sequence; Buffers; Chromatography, High Pressure Liquid; Dimethyl Sulfoxide; DNA; Drug Stability; Hydrolysis; Kinetics; Nitrogen Mustard Compounds - chemistry; Nucleic Acid Conformation; Nucleic Acids - chemistry; Oligodeoxyribonucleotides - chemical synthesis; Oligodeoxyribonucleotides - chemistry; Quaternary Ammonium Compounds - chemistry; Solubility
• ISSN: 1043-1802; 1520-4812
• DOI: 10.1021/bc970134a

A versatile method is described for preparing aryl nitrogen mustard−oligodeoxyribonucleotide (mustard−ODN) conjugates under anhydrous conditions. The chemistry uses DMSO soluble triethylammonium or tributylammonium salts of the ODNs. A G/A motif triplex forming ODN was chosen for study since it had been shown earlier to bind with high affinity and specificity to a duplex DNA target. A 5‘-hexylamine derivative of this ODN was reacted with three different 2,3,5,6-tetrafluorophenyl ester derivatives of aryl nitrogen mustards which were designed to have different alkylation rates. An HPLC assay was used to determine reaction rates of these mustard−ODNs under various conditions. The reactivity of the mustard groups depended on chloride concentration and the presence of nucleophiles. Conjugation of mustards to G/A-containing ODNs decreased their aqueous stability. Hydrolysis and alkylation rates of these agents were consistent with reaction via an aziridinium intermediate. Rates of sequence specific alkylation within a triplex were determined by denaturing gel electrophoresis and shown to depend on inherent reactivity of the mustard group. The improved synthesis and chemical characterization of mustard−ODNs should facilitate their use as sequence specific alkylating agents and as probes for nucleic acid structure.