- Determination of binding modes and binding constants for the complexes of 6H-pyrido[4,3-b]carbazole derivatives with DNA
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The binding modes and binding constants for the complexes of forty types of pyridocarbazole derivatives 1–40 with double stranded DNAs (dsDNAs) were reported. The binding modes were determined by a combination of a deflection spectroscopy and orientation of the corresponding molecule in the DNA-based film with chain alignment. All of the compounds exhibited the intercalation-binding mode. Its binding constants Kafor the complexes, determined by quartz crystal microbalance (QCM), varied from 1.7?×?105to 4.5?×?107?M?1according to the substituents on the pyridocarbazole framework and the sequences of dsDNA. The binding constants Kaof pyridocarbazole derivatives possessing the 2-(ω-amino)alkyl group and 5-(ω-amino)alkylcarbamyl group were larger than those of the corresponding ω-ureido derivatives. These ω-amino compounds exhibited strong GC base-pair preference in complexation. The Kavalues decreased with the increasing NaCl concentration. It was clarified by a molecular modeling that the framework of the 2-tethered ω-amino derivative was completely overlapped with the stacking GC base-pairs leading to the formation of the stable intercalative-complex, and that the framework of the 5-tethered ureido derivative was half overlapped leading to the formation of the unstable complex. Furthermore, there were good linear relationships between ln?Kaand the relative stabilities Srelof the complexes. Contrary to our expectation, there was no linear relationship between ln?Kaand IC50against Sarcoma-180, NIH3T3, and HeLa S-3 cell lines.
- Shimazu, Akihito,Kawagoshi, Masashi,Takeda, Shoichi,Kurasaki, Haruaki,Kato, Asako,Morii, Nahoko,Sakai, Norio,Konakahara, Takeo
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p. 1094 - 1112
(2017/02/18)
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- Fluorometric recognition of both dihydrogen phosphate and iodide by a new flexible anthracene linked benzimidazolium-based receptor
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A new flexible anthracene linked benzimidazolium-based receptor 1 has been designed, synthesized and its binding properties have been studied by NMR, UV-vis and fluorescence spectroscopic techniques. While the receptor 1 exhibits a greater change in emission in the presence of tetrabutylammonium dihydrogenphosphate in CH3CN over the other anions studied, iodide is selectively preferred in CHCl3 containing 0.1% CH3CN. Upon complexation of dihydrogen phosphate and iodide, the emission of 1 gradually decreased without showing any other characteristic change in the spectra. Hydrogen bonding and charge-charge interactions interplay simultaneously in a cooperative manner for selectivity in the binding process.
- Ghosh, Kumaresh,Kar, Debasis
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experimental part
p. 254 - 264
(2011/06/09)
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- EFFICIENT SYNTHESIS OF SECONDARY CARBOXAMIDES WITH Ω-SUBSTITUTED ETHYL AND PROPYL GROUPS ON NITROGEN ATOM BY NUCLEOPHILIC RING OPENING OF CYCLIC IMIDATES
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An efficient synthesis of secondary carboxamides carrying ω-substituted ethyl and propyl groups on nitrogen atom has been developed which highlights nucleophilic ring opening of 2-methyl-2-oxazoline, 2-methyl-2-oxazine, and their derivatives with (CH3)3SiX and HX (X=Cl, N3, SeC6H5, SC6H5) type reagents.
- Saito, Seiki,Tamai, Hideaki,Usui, Yuki,Inaba, Masami,Moriwake, Toshio
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p. 1243 - 1246
(2007/10/02)
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