186040-29-9Relevant academic research and scientific papers
Hoechst 33258 tethered by a hexa(ethylene glycol) linker to the 5'-termini of oligodeoxynucleotide 15-mers: Duplex stabilization and fluorescence properties
Rajur,Robles,Wiederholt,Kuimelis,McLaughlin
, p. 523 - 529 (1997)
A fluorescent Hoechst 33258 derivative has been prepared in which a hexa(ethylene glycol) linker is attached to the terminal phenol residue. Conjugation of this derivative to DNA sequences is accomplished by a reversed coupling protocol, one in which the 5'-terminal nucleoside residue of a fully protected DNA sequence is converted to a terminal phosphoramidite. In the presence of the Hoechst derivative and tetrazole the final coupling reaction is achieved to generate the conjugated nucleic acid. After deprotection and cleavage of the conjugate from the support, HPLC analysis indicates that the conjugation reaction proceeds with yields as high as 75%. The presence of the conjugated Hoechst derivative increases the stability of DNA duplexes typically by 10-16°C. A variety of sequence variants indicate that the tether length is sufficient to reach beyond the terminus of the DNA duplex and bind to internal A-T rich target sequences as far away as four base pairs from the site of attachment. A four base pair binding site appears to be necessary for effective helix stabilization by the conjugate, but in some cases can include a G-C base pair, which is consistent with a previous X-ray diffraction study regarding the binding of Hoechst 33258 to duplex DNA. When A-T base pairs alternate with G-C base pairs, a small but discernible increase is T(m) is observed (3.6°C), indicating that binding to this sequence still occurs, but not in the same manner as to A-T rich sequences. Upon formation of the conjugated duplex, an enhanced quantum yield for the fluorescence emission spectrum of the tethered Hoechst derivative is observed. When an A-T rich binding site is present, the enhanced quantum yield increases by at least 16- and in some cases to nearly 30-fold relative to the value obtained for the single-stranded DNA-Hoechst conjugate.
Photo/nickel synergistic catalysis method for monoarylation of diol
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Paragraph 0043; 0092-0095, (2018/09/13)
The invention discloses a photo/nickel synergistic catalysis method for monoarylation of a diol. The method directly uses a brominated aromatic hydrocarbon and a diol as raw materials, wherein the brominated aromatic hydrocarbon and the diol are simple and easy to obtain, and adopts a BODIPY organic photosensitizer and an inexpensive nickel source to synergistically catalyze cross-coupling of thediol and the brominated aromatic hydrocarbon without an additionally-added ligand to realize selective monoarylation of a diol compound, and a mono/dual arylation ratio is up to 18:1. The method disclosed by the invention has good tolerance of functional groups and is suitable for a plurality of diol compounds with different structures, such as o-diol, 1,3-diol, 1,4-diol and monodisperse polyethylene glycol; more importantly, the photosensitizer used in the method has a low using amount, the reaction temperature is close to room temperature, and the method is green, economical and highly-efficient; and the advantages make the method have higher scale synthetic value and can serve social and economic development.
