Anion-Sensing Properties of Cyclopentaphenylalanine

Molecules

Vladislav Tomišić¹  Ivan Petters¹  Matija Modrušan¹  Nikola Cindro¹  Gordan Horvat¹  Nikolina Vidović²  Giovanna Speranza²  Ivo Piantanida³  Ivo Crnolatac³ 

[1] Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia;Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi, 19, 20133 Milan, Italy;Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia;

关键词: cyclopeptide;    anion binding;    fluorimetry;    circular dichroism;    UV spectrometry;    ¹H NMR;   

DOI  :  10.3390/molecules27123918

来源: DOAJ

【 摘 要 】

Cyclic pentaphenylalanine was studied as an efficient anion sensor for halides, thiocyanate and oxoanions in acetonitrile and methanol. Stability constants of the corresponding complexes were determined by means of fluorimetric, spectrophotometric, ¹H NMR, and microcalorimetric titrations. A detailed structural overview of receptor–anion complexes was obtained by classical molecular dynamics (MD) simulations. The results of ¹H NMR and MD studies indicated that the bound anions were coordinated by the amide groups of cyclopeptide, as expected. Circular dichroism (CD) titrations were also carried out in acetonitrile. To the best of our knowledge, this is the first example of the detection of anion binding by cyclopeptide using CD spectroscopy. The CD spectra were calculated from the structures obtained by MD simulations and were qualitatively in agreement with the experimental data. The stoichiometry of almost all complexes was 1:1 (receptor:anion), except for dihydrogen phosphate where the binding of dihydrogen phosphate dimer was observed in acetonitrile. The affinity of the cyclopeptide receptor was correlated with the structure of anion coordination sphere, as well as with the solvation properties of the examined solvents.

【 授权许可】

Unknown