Naslov
Synthesis and Characteristics of Novel Peptidocalix[4]arenes with Tryptophan Subunits

Autori
Burić, Nataša ; Galić, Nives ; Tomišić, Vladislav ; Žinić, Mladen ; Frkanec, Leo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
15th European Symposium on Organic Chemistry : Abstracts (ESOC 15) / Guiry, Pat ; Mooney, Ann - Dublin : University College, 2007, 168-168

Skup
15th European Symposium on Organic Chemistry

Mjesto i datum
Dublin, Irska, 08.07.2007. - 13.07.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
supramolecular ; peptidocalixarenes ; ion-complexing ; chemical sensors ; fluroionophores

Sažetak
One of the most attractive features of calixarenes is the ease of their chemical modification which makes it possible to change the ion-complexing selectivity of these compounds simply by switching from one ligating functional group to another. It was shown that calixarenes endowed with alpha-amino acids or peptides (peptidocalixarenes) [1] could efficiently and selectively bind smaller alkali metal cations (Li+ and Na+) [2]. A new class of calix[4]arene derivatives bearing two or four tryptophan units at the lower rim were designed as potential chemical sensors or fluroionophores for metal cations. Compound 5, 11, 17, 23-tetra-tert-butyl-25, 26, 27, 28-tetrakis(O-methyl-L-tryptophanylcarbonyl methoxy)calix[4]arene (L1) was synthesised in four reaction steps. The reaction of 5, 11, 17, 23-tetra-tert-butyl-25, 26, 27, 28-tetrakis(chlorophormylmethoxy)calix[4]arene with L-tryptophan methyl ester hydrochloride and triethylamine gave L1 in 55 % yield. Starting from 5, 11, 17, 23-tetra-tert-butyl-25, 27-dihydroxy-26, 28-di(O-methyl)calix[4]arene compound L2 (5, 11, 17, -23-tetra-tert-butyl-25, 27-di(O-methyl)-26, 28-bis(O-methyl-L-tryptophanylcarbonylmethoxy)calix-[4]arene) was prepared in 63 % yield in four reaction steps. Compound L1 adopts a cone conformation in solution at room temperature while compound L2 is a mixture of different conformers as proved by NMR spectroscopy. The complexation of alkali metal cations with compounds L1 and L2 in acetonitrile was studied by spectrophotometric, spectrofluorimetric and conductometric titrations. Calixarene derivative L1 efficiently binds lithium and sodium and moderately potassium metal ions, while L2 having a more flexible cavity binds larger rubidium ion as well.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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