Benzylsulfonamide was used as a source of nitrogen in the syn- thesis of azacrown ethers,and the cyclic intermediates were easily deben- zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.
A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were det...A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.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
The 6-hydroxymethyl-6'-tetrahydropyranyloxymethyl-2, 2'-bipyridine (2) was synthesized by the reaction of 6,6'-dihydroxymethyl-2, 2'-bipyridine (1) with 3, 4-dihydroxypyran (DHP). 6.Tetrahydropyranylox...The 6-hydroxymethyl-6'-tetrahydropyranyloxymethyl-2, 2'-bipyridine (2) was synthesized by the reaction of 6,6'-dihydroxymethyl-2, 2'-bipyridine (1) with 3, 4-dihydroxypyran (DHP). 6.Tetrahydropyranyloxymethyl-6'-iodomethyl-2, 2'-bipyridine (5) was obtained from mesylate and iodizating reaction of compound 2. The coupling of 2 and 5 followed by hydrolysis gave bis(6'-hydroxymethyl-2, 2'-bipyridine-6-methyl) ether (7). The macrocyclic ligand 8 was obtained by treating 7 and 6, 6'-dibromethyl-2, 2'-bipyridine. The synthetic conditions of the intermediate 2 and macocyclic ligand 8 were discussed.展开更多
文摘Benzylsulfonamide was used as a source of nitrogen in the syn- thesis of azacrown ethers,and the cyclic intermediates were easily deben- zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.
文摘A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.
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.
文摘The 6-hydroxymethyl-6'-tetrahydropyranyloxymethyl-2, 2'-bipyridine (2) was synthesized by the reaction of 6,6'-dihydroxymethyl-2, 2'-bipyridine (1) with 3, 4-dihydroxypyran (DHP). 6.Tetrahydropyranyloxymethyl-6'-iodomethyl-2, 2'-bipyridine (5) was obtained from mesylate and iodizating reaction of compound 2. The coupling of 2 and 5 followed by hydrolysis gave bis(6'-hydroxymethyl-2, 2'-bipyridine-6-methyl) ether (7). The macrocyclic ligand 8 was obtained by treating 7 and 6, 6'-dibromethyl-2, 2'-bipyridine. The synthetic conditions of the intermediate 2 and macocyclic ligand 8 were discussed.