The spectrophotometric titrations have been performed at 298.15 K in buffered aqueous solution （pH 7.20） to give the stability constants （logK-s） for the supramolecular system formed by mono-[6-（phenylseleno）-6-...The spectrophotometric titrations have been performed at 298.15 K in buffered aqueous solution （pH 7.20） to give the stability constants （logK-s） for the supramolecular system formed by mono-[6-（phenylseleno）-6-deoxy]-β-cyclodextrin （2）, mono-[6-（p-tolylseleno）-6-deoxy]-β-cyclodextrin （3）, mono-[6-（o-tolylseleno）-6-deoxy]-β-cyclodextrin （4）, mono-[6-（m-tolylseleno）-6-deoxy]-β-cyclodextrin （5） with a series of aliphatic alcohols. The results were compared with the data reported for the parent β-cyclodextrin. The molecular binding ability and selectivity for aliphatic alcohols of modified β-cyclodextrins （25） were discussed from the viewpoints of the induced-fit and geometrical complement. The results obtained indicate that the phenylseleno moiety of β-cyclodextrin derivatives （25） as a probe for spectrometry can enhance not only the molecular binding ability but also the molecular recognition ability.展开更多
A simple and sensitive electroanalytical method for determination of shikonin, a widely used antitumoral agent, using β-cyclodextrin-functionalized multiwalled carbon nanotubes composite modified glassy carbon electr...A simple and sensitive electroanalytical method for determination of shikonin, a widely used antitumoral agent, using β-cyclodextrin-functionalized multiwalled carbon nanotubes composite modified glassy carbon electrodes （MWCNTs/β-CD/GCE） was presented. CDs are water-soluble and environmentally friendly and can improve the dispersibility of MWCNTs/βCD functional materials, which was confirmed by SEM. The electrochemical behaviors of shikonin on different electrodes were investigated by cyclic voltammetry （CV） and differential pulse voltammograms （DPVs）. The results demonstrated that the redox peak currents of shikonin obtained at MWCNTs/fl-CD/GCE were much higher than those at the βCD/GCE and MWCNTs/GCE, which can be attributed to the combination of the excellent electrocatalytic properties of MWCNTs and the molecular recognition ability of βCD. At MWCNTs/ βCD/GCE, the response current exhibits a linear range from 5.0 nmol/L to 10.0 μmol/L with a detection limit of 1.0nmol/L （S/N=3）. As a practical application, the proposed method was applied to quantitatively determine shikoninin urine samples with satisfying results.展开更多
p-dimethylaminobenzonitrile (DMABN), a typical dual fluorescent flurophor (TICTflurophore), was used as fluorescent probe. The microenviromental property of twelve methyl modified β-cyclodextrin(methyl β-CD) was com...p-dimethylaminobenzonitrile (DMABN), a typical dual fluorescent flurophor (TICTflurophore), was used as fluorescent probe. The microenviromental property of twelve methyl modified β-cyclodextrin(methyl β-CD) was compared with that of β-cyclodextrin (β-CD). Results showed that the polarity of the cavity of methyl β-CD is lower than that of β- CD, and the capacity of methyl β-CD inclusion with DMABN is stronger than that of β-CD inclusion with DMABN.展开更多
文摘The spectrophotometric titrations have been performed at 298.15 K in buffered aqueous solution （pH 7.20） to give the stability constants （logK-s） for the supramolecular system formed by mono-[6-（phenylseleno）-6-deoxy]-β-cyclodextrin （2）, mono-[6-（p-tolylseleno）-6-deoxy]-β-cyclodextrin （3）, mono-[6-（o-tolylseleno）-6-deoxy]-β-cyclodextrin （4）, mono-[6-（m-tolylseleno）-6-deoxy]-β-cyclodextrin （5） with a series of aliphatic alcohols. The results were compared with the data reported for the parent β-cyclodextrin. The molecular binding ability and selectivity for aliphatic alcohols of modified β-cyclodextrins （25） were discussed from the viewpoints of the induced-fit and geometrical complement. The results obtained indicate that the phenylseleno moiety of β-cyclodextrin derivatives （25） as a probe for spectrometry can enhance not only the molecular binding ability but also the molecular recognition ability.
基金the National Natural Science Foundation of China(No.51302117)the Natural Science Foundation of Jiangxi Province(Nos.20122BAB216011 and 20122BAB213007)+2 种基金Jiangxi Provincial Department of Education(No.GJJ13258)Postdoctoral Science Foundation of China(No.2014M551857)the Science and Technology Landing Plan of Universities in Jiangxi province (No.KJLD12081) for their financial support of this work
文摘A simple and sensitive electroanalytical method for determination of shikonin, a widely used antitumoral agent, using β-cyclodextrin-functionalized multiwalled carbon nanotubes composite modified glassy carbon electrodes （MWCNTs/β-CD/GCE） was presented. CDs are water-soluble and environmentally friendly and can improve the dispersibility of MWCNTs/βCD functional materials, which was confirmed by SEM. The electrochemical behaviors of shikonin on different electrodes were investigated by cyclic voltammetry （CV） and differential pulse voltammograms （DPVs）. The results demonstrated that the redox peak currents of shikonin obtained at MWCNTs/fl-CD/GCE were much higher than those at the βCD/GCE and MWCNTs/GCE, which can be attributed to the combination of the excellent electrocatalytic properties of MWCNTs and the molecular recognition ability of βCD. At MWCNTs/ βCD/GCE, the response current exhibits a linear range from 5.0 nmol/L to 10.0 μmol/L with a detection limit of 1.0nmol/L （S/N=3）. As a practical application, the proposed method was applied to quantitatively determine shikoninin urine samples with satisfying results.
文摘p-dimethylaminobenzonitrile (DMABN), a typical dual fluorescent flurophor (TICTflurophore), was used as fluorescent probe. The microenviromental property of twelve methyl modified β-cyclodextrin(methyl β-CD) was compared with that of β-cyclodextrin (β-CD). Results showed that the polarity of the cavity of methyl β-CD is lower than that of β- CD, and the capacity of methyl β-CD inclusion with DMABN is stronger than that of β-CD inclusion with DMABN.
