- Photoinduced DNA Interstrand Cross-Linking by Benzene Derivatives: Leaving Groups Determine the Efficiency of the Cross-Linker
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We have synthesized and characterized two small libraries of 2-OMe or 2-NO2-benzene analogues 2a-i and 3a-i containing a wide variety of leaving groups. Irradiation of these compounds at 350 nm generated benzyl radicals that were spontaneously oxidized to
- Fan, Heli,Peng, Xiaohua
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p. 493 - 506
(2020/12/22)
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- Substituents Have a Large Effect on Photochemical Generation of Benzyl Cations and DNA Cross-Linking
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Photoactivated DNA interstrand cross-linking agents have a wide range of biological applications. Recently, several aryl boronates have been reported to induce DNA interstrand cross-link (ICL) formation via carbocations upon photoirradiation. Herein, we synthesized a series of new bifunctional phenyl compounds to test the generality of such a mechanism, and to understand how the chemical structure influences carbocation formation and the DNA cross-linking process. These compounds efficiently form DNA ICLs via generated benzyl cations upon 350 nm irradiation. The DNA cross-linking efficiency and the pathway for carbocation generation depend on both the aromatic substituents and the leaving groups. Bromine as a leaving group facilitates the DNA cross-linking process in comparison with trimethyl ammonium salt. Both electron-donating and -withdrawing substituents induce bathochromic shifts, which favor photoinduced DNA ICL formation. For the bromides, the benzyl cation intermediates were generated through oxidation of the corresponding benzyl radicals. However, for the ammonia salts, the benzyl cations were formed through two pathways: either through oxidation of the benzyl radicals or by direct heterolysis of the C?N bond. Photoinduced C?N homolysis to form benzyl radicals occurred with compounds having donating substituents, whereas direct heterolysis of the C?N bond occurred with those bearing withdrawing substituents. The adducts formed between 1 a and four natural nucleosides were characterized, indicating that the alkylation sites for the photogenerated benzyl cations are dG, dA, and dC.
- Fan, Heli,Sun, Huabing,Peng, Xiaohua
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p. 7671 - 7682
(2018/05/14)
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- Synthesis and Enantioselective Coloration of Optically Active Azophenolic Acerands incorporating Two 1,1'-Binaphthyl Moieties as the Chiral Centre
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Two chiral azophenolic acerands 2 and 3 with two 1,1'-binaphthyl moieties as the chiral centre have been prepred, and their chiral recognition properties based on enantiomeric amine-selective coloration have been examined; the host 3 shows a higher enanti
- Yamamoto, Koji,Isoue, Koichiro,Sakata, Yoshiteru,Kaneda, Takahiro
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p. 791 - 793
(2007/10/02)
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- Mono and bis(bioreductive) alkylating agents: Synthesis and antitumor activities in a B16 melanoma model
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Several potentially bis(alkylating) bis(quinones) (3-5) and 1,4- and 1,3-bis(alkylating) monoquinones (6-13) belonging to general structure 2,2'-ethylenebis[5-[(leaving group) methyl]-1,4-benzoquinone] (3-5) and 2,5- and 2,6-bis[(leaving group)methyl]-1,4
- Witiak,Loper,Ananthan,Almerico,Verhoef,Filppi
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p. 1636 - 1642
(2007/10/02)
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- Light Absorption and Emission Properties of Cyanovinyl-substituted Dimethoxybenzenes
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Synthetic routes to a range of dyes based on cyanovinyl-substituted dimethoxybenzenes are described.The light absorption and fluorescence properties of these compounds in fluid solution at room temperature are discussed.
- Chu, Kwong Yung,Griffiths, John,Ward, David
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p. 3701 - 3721
(2007/10/02)
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