24471-48-5Relevant academic research and scientific papers
Erratum: Redox-Noninnocent Ligand-Supported Vanadium Catalysts for the Chemoselective Reduction of C=X (X = O, N) Functionalities (Journal of the American Chemical Society (2019) 141:38 (15230-15239) DOI: 10.1021/jacs.9b07062)
Zhang, Guoqi,Wu, Jing,Zheng, Shengping,Neary, Michelle C.,Mao, Jincheng,Flores, Marco,Trovitch, Ryan J.,Dub, Pavel A.
supporting information, p. 16507 - 16509 (2020/10/14)
Pages 15232, 15233, and 15236. In the original paper, the doublet wave functions for 21 and 21a/21b were incorrectly (Figure Presented). reported as spin-contaminated in sections 2.3 and 2.8 (Figure 3 and Scheme 9, respectively.) This comes from the incorrectly reported expected eigenvalue of 0.75 for the spin-squared operator ??2? for the antiferromagnetically coupled doublet |↓?L|↑↑?V state (originally given in the Supporting Information). The correct expected eigenvalue for the |↓?L|↑↑?V state should be 1.75. The wave functions for 21 and 21a/21b (eigenvalues 1.79 and 1.77/1.66, respectively) are therefore not spincontaminated. The corrected Figure 3 and Scheme 9 are presented below. A corrected Supporting Information file is also provided. The corrections do not affect any of the conclusions of the Article, but slightly decrease the gap between the quartet and doublet spin surfaces. Scheme 3 has been also corrected to reflect the fact that (CH3)3SiCH2 ? radicals can only react based on spin conservation.
Recognition of double-stranded DNA using energetically activated duplexes with interstrand zippers of 1-, 2- or 4-pyrenyl-functionalized O2′-alkylated RNA monomers
Karmakar, Saswata,Madsen, Andreas S.,Guenther, Dale C.,Gibbons, Bradley C.,Hrdlicka, Patrick J.
supporting information, p. 7758 - 7773 (2015/01/09)
Despite advances with triplex-forming oligonucleotides, peptide nucleic acids, polyamides and-more recently-engineered proteins, there remains an urgent need for synthetic ligands that enable specific recognition of double-stranded (ds) DNA to accelerate studies aiming at detecting, regulating and modifying genes. Invaders, i.e., energetically activated DNA duplexes with interstrand zipper arrangements of intercalator-functionalized nucleotides, are emerging as an attractive approach toward this goal. Here, we characterize and compare Invaders based on 1-, 2- and 4-pyrenyl-functionalized O2′-alkylated uridine monomers X-Z by means of thermal denaturation experiments, optical spectroscopy, force-field simulations and recognition experiments using DNA hairpins as model targets. We demonstrate that Invaders with +1 interstrand zippers of X or Y monomers efficiently recognize mixed-sequence DNA hairpins with single nucleotide fidelity. Intercalator-mediated unwinding and activation of the double-stranded probe, coupled with extraordinary stabilization of probe-target duplexes (ΔTm/modification up to +14.0 °C), provides the driving force for dsDNA recognition. In contrast, Z-modified Invaders show much lower dsDNA recognition efficiency. Thus, even very conservative changes in the chemical makeup of the intercalator-functionalized nucleotides used to activate Invader duplexes, affects dsDNA-recognition efficiency of the probes, which highlights the importance of systematic structure-property studies. The insight from this study will guide future design of Invaders for applications in molecular biology and nucleic acid diagnostics.
Efficient oxidation of promutagenic hydroxymethylpyrenes by cDNA-expressed human alcohol dehydrogenase ADH2 and its inhibition by various agents
Kollock, Ronny,Meinl, Walter,Schneider, Heiko,Batke, Monika,Frank, Heinz,Seidel, Albrecht,Glatt, Hansruedi
, p. 527 - 537 (2008/03/14)
Alkylated polycyclic aromatic hydrocarbons can be metabolically activated via benzylic hydroxylation and sulphation to electrophilically reactive esters. However, we previously found that the predominant biotransformation route for the hepatocarcinogen 1-hydroxymethylpyrene (1-HMP) in the rat in vivo is the oxidation of the side chain by alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases to the carboxylic acid. Inhibition of this pathway by ethanol (competing ADH substrate) or 4-methylpyrazole (ADH inhibitor) led to a dramatic increase in the 1-HMP-induced DNA adduct formation in rat tissues in the preceding study. In order to elucidate the role of individual ADHs in the metabolism of alkylated polycyclic aromatic hydrocarbons, we expressed the various members of the human ADH family in bacteria. Cytosolic preparations from bacteria expressing ADH2 clearly oxidized hydroxymethylpyrene isomers (1-, 2- and 4-HMP) with the highest rate. This form was purified to near homogeneity to perform detailed kinetic analyses. High catalytic efficiencies (Vmax/Km) were observed with HMPs. Thus, this value was 10,000-fold higher for 2-HMP than for the reference substrate, ethanol. The corresponding aldehydes were also efficiently reduced by ADH2. 4-Methylpyrazole inhibited the oxidation of the HMP isomers as well as the reverse reaction. Daidzein, cimetidine and the competing substrate ethanol were further compounds that inhibited the ADH2-mediated oxidative detoxification of 1-HMP.
Intramolecular excimer formation and delayed fluorescence in sterically constrained pyrene dimers
Benniston, Andrew C.,Harriman, Anthony,Howell, Sarah L.,Sams, Craig A.,Zhi, Yong-Gang
, p. 4665 - 4674 (2008/02/08)
The synthesis is described for a series of five molecular dyads comprising pyrene-based terminals covalently linked through a 1,3-disubstituted phenylene spacer. The extent of through-space communication between the pyrene units is modulated by steric int
Charge Delocalization Pathways in Persistent 1-Pyrenyl-, 4-Pyrenyl-, and 2-Pyrenylmethylcarbenium Ions as Models of PAH-Epoxide Ring Opening: NMR Studies in Superacids and AMI Calculations
Laali, Kenneth K.,Hansen, Poul Erik
, p. 5804 - 5810 (2007/10/03)
The relative stability, magnitude, and mode of charge delocalization into the pyrene moiety (Py) were evaluated for a series of tertiary and secondary 1-pyrenylmethylcarbenium ions PyC+R1R2 and PyC+R3
