The palladium(0)-catalyzed alkylation reaction of allylic oxygenates has found extensive use in organic synthesis. Recent efforts, however, have focused on the development of catalytic methods to replace allylic C H bonds directly with C C bonds. The selective alkylation of normally inert C H bonds presents exciting opportunities for the development of novel methods and streamlined syntheses of...

Synthesis and spectroscopic analysis of some alkylated DNA purine bases are described. HPLC separation methods are developed for the determination of DNA alkylation rates in mammalian embryonic tissues. Following treatment of pregnant mice with the ethylating agent ethylmethanesulfonate (EMS), an appreciable amount of alkylation (ethylation and methylation) was found in the nuclear DNA of the e...

Reaction with thiol converts the antitumor natural product leinamycin to an episulfonium ion that alkylates the N(7)-position of guanine residues in double-stranded DNA. The sequence specificity for DNA alkylation by this structurally novel compound has not previously been examined. It is reported here that leinamycin shows significant (>10-fold) preferences for alkylation at the 5'-G in 5'-GG ...

An in-situ reactor was elaborately designed for O-alkylation of chitosan in an ionic liquid ([BMIM]Cl) solvent, using N, N'-carbonyldiimidazole as bonding agent. The original chitosan and the modified chitosan were characterized by FT-IR and XRD analysis. FT-IR spectra revealed that the alkylation of chitosan selectively occurred at hydroxyl groups, with unprotected amino groups untouched. It w...

1. The incorporation of methyl groups into histones from dimethylnitrosamine and from methionine was studied by injection of the labelled compounds, isolation of rat liver and kidney histones, and analysis of hydrolysates by column chromatography. 2. Labelled methionine gave rise to labelled in-N-methyl-lysine, di-in-N-methyl-lysine and an amino acid presumed to be omega-N-methyl-arginine. 3. A...

Attachment of a nondiffusible bromoacetyl electrophile to the 5-position of a thymine at the 5'-end of a pyrimidine oligodeoxyribonucleotide affords sequence-specific alkylation of a guanine base in duplex DNA two base pairs to the 5'-side of a local triple-helical complex. Products resulting from reaction of 5'-ETTTTMeCTTTTMeCMeCTTTMeCTTTT-3' at 37 degrees C with a 29 base pair target duplex a...

Cigarette smoking remains a major health concern worldwide, and many of the adverse effects of cigarette smoke (CS) can be attributed to its abundant electrophilic aldehydes, such as acrolein (2-propenal). Previous studies indicate that acrolein readily reacts with thioredoxin reductase 1 (TrxR1), a critical enzyme involved in regulation of thioredoxin (Trx)-mediated redox signaling, by alkylat...

Alkylation of the sugar-phosphate backbone of DNA can result upon exposure to several potent carcinogens, inducing DNA misfunction. In order to assess the structural and energetic changes in DNA helices induced by such alkylation, we have performed AMBER-based analyses on phosphotriester containing analogues of (d-[GGAATTCC])2. Fourteen analogues of the nonalkylated oligomer were examined, each...

The chemistry of the 5,7-dihydro-6H-pyrrolo[2,3-d]pyrimidin-6-one (1,3-diazaoxindole) compound family, possessing a drug-like scaffold, is unexplored. In this study, the alkylation reactions of N(7)-unsubstituted 5-isopropyl-1,3-diazaoxindoles bearing various substituents at the C(2) position have been investigated. The starting compounds were synthesized from the C(5)-unsubstituted parent comp...

Major increases of the selectivity and/or reactivity in aminosugar and sugar O-alkylation were observed in the presence of tetrabutylammonium fluoride (TBAF) in comparison to TBAI under phase-transfer conditions or in solution. The presence of TBAF allowed the selective and rapid alkylation of the 6hydroxyl function of neamine and efficient preparation of protected intermediates useful in synth...