(1R,2R,3S,4R,7R)-7-Isopropyl-6-methylbicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid anhydride(tetrahydro-4,7-ethanoisobenzofuran-1,3-dione derivative)adduct 2 was prepared via the isomerization ofα-pinene andβ-pinene...(1R,2R,3S,4R,7R)-7-Isopropyl-6-methylbicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid anhydride(tetrahydro-4,7-ethanoisobenzofuran-1,3-dione derivative)adduct 2 was prepared via the isomerization ofα-pinene andβ-pinene in turpentine followed by the Diels-Alder cycloaddition with maleic anhydride in the presence of phosphoric acid/iodine catalysis.The molecular structure of adduct 2 was characterized by IR,1H NMR,13C NMR,1H-1H COSY,DEPT,HSQC,HMBC,2D NOESY and MS spectra.The single crystal X-ray crystallographic analysis of adduct 2 was performed,and the X-ray powder diffractive spectrum of the sample adduct 2 is consistent with the diffractive spectrum calculated from the single crystal data.Therefore the structure and stereochemistry of adduct 2 was established based on extensive spectral data and single crystal X-ray analysis.展开更多
New metal-free DNA cleaving reagent 1,1,4,7-triazacrown(TACN)both with aminoethyl,hydroxyethyl side arms and a planar anthraquinone linked by an alkyl(1,6-hexamethylene)spacer has been synthesized and characterized by...New metal-free DNA cleaving reagent 1,1,4,7-triazacrown(TACN)both with aminoethyl,hydroxyethyl side arms and a planar anthraquinone linked by an alkyl(1,6-hexamethylene)spacer has been synthesized and characterized by NMR and MS spectrometry.For comparison,the corresponding aminoethyl,hydroxyethyl triazacrown derivative 2 without the anthraquinone has also been synthesized.DNA-binding properties via fluorescence and CD spectroscopy indicate that the binding affinity of 1 with DNA is much stronger than that of 2.Agarose gel electrophoresis was used to assess plasmid pUC19 DNA cleavage.Kinetic data of DNA cleavage promoted by 1,2 and parent triazacrown(TACN)3 under physiological condition give the 15-fold and 234-fold rate acceleration of compound 1 over 2 and parent triazacrown 3.Radical scavenger inhibition study suggests that DNA cleavage promoted by 1 may be a non-oxidative pathway through the transphosphorylation and then hydrolysis.The dramatic rate acceleration is due not only to the anthraquinone moiety of compound 1 intercalating into DNA base pairs via stacking interaction,but also the cooperative catalysis of the nucleophilic hydroxyl and the electrophilic ammonium group for the cleavage of phosphodiester of DNA.展开更多
基金the National Natural Science Foundation of China(Nos.31200451,21304048)the Natural Science Foundation of Jiangsu Province(No.BK2012821)the Foundation of Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘(1R,2R,3S,4R,7R)-7-Isopropyl-6-methylbicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid anhydride(tetrahydro-4,7-ethanoisobenzofuran-1,3-dione derivative)adduct 2 was prepared via the isomerization ofα-pinene andβ-pinene in turpentine followed by the Diels-Alder cycloaddition with maleic anhydride in the presence of phosphoric acid/iodine catalysis.The molecular structure of adduct 2 was characterized by IR,1H NMR,13C NMR,1H-1H COSY,DEPT,HSQC,HMBC,2D NOESY and MS spectra.The single crystal X-ray crystallographic analysis of adduct 2 was performed,and the X-ray powder diffractive spectrum of the sample adduct 2 is consistent with the diffractive spectrum calculated from the single crystal data.Therefore the structure and stereochemistry of adduct 2 was established based on extensive spectral data and single crystal X-ray analysis.
基金This work was supported by the National Science Foundation(No.31170536)the Foundation of Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions(2010).
文摘New metal-free DNA cleaving reagent 1,1,4,7-triazacrown(TACN)both with aminoethyl,hydroxyethyl side arms and a planar anthraquinone linked by an alkyl(1,6-hexamethylene)spacer has been synthesized and characterized by NMR and MS spectrometry.For comparison,the corresponding aminoethyl,hydroxyethyl triazacrown derivative 2 without the anthraquinone has also been synthesized.DNA-binding properties via fluorescence and CD spectroscopy indicate that the binding affinity of 1 with DNA is much stronger than that of 2.Agarose gel electrophoresis was used to assess plasmid pUC19 DNA cleavage.Kinetic data of DNA cleavage promoted by 1,2 and parent triazacrown(TACN)3 under physiological condition give the 15-fold and 234-fold rate acceleration of compound 1 over 2 and parent triazacrown 3.Radical scavenger inhibition study suggests that DNA cleavage promoted by 1 may be a non-oxidative pathway through the transphosphorylation and then hydrolysis.The dramatic rate acceleration is due not only to the anthraquinone moiety of compound 1 intercalating into DNA base pairs via stacking interaction,but also the cooperative catalysis of the nucleophilic hydroxyl and the electrophilic ammonium group for the cleavage of phosphodiester of DNA.
