Termodinamičko i strukturno istraživanje kompleksiranja metilnih estera tetra i heksafenilalanina s anionima u acetonitrilu

master's thesis

• Title (english): Thermodynamic and structural studies on the complexation of methyl esters of tetra and hexaphenylalanine with anions in acetonitrile
• Author: Lucija Glazer
• Mentor: Gordan Horvat (mentor)
• Committee member: Gordan Horvat (predsjednik povjerenstva)
• Committee member: Željka Soldin (član povjerenstva)
• Committee member: Iva Juranović Cindrić (član povjerenstva)
• Committee member: Tajana Begović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2023-05-31, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Ciklički peptidi predstavljaju posebno zanimljivu klasu supramolekulskih anionskih receptora zbog svoje raznolikosti i vrlo dobrih kompleksacijskih svojstava. Prvi korak sinteze cikličkih peptida je priprava njihovih linearnih analoga, a zatim se provodi reakcija ciklizacije. Najvažnija komponenta uspješne ciklizacije je konformacijska preorganizacija linearnog peptida u kojoj dolazi do približavanja N i C reaktivnih krajeva. Preorganizacija se može pospješiti korištenjem templatnih iona. U ovom radu istraženo je kompleksiranje metilnih estera linearnog tetra i heksafenilalanina s halogenidnim i oksoanionima u acetonitrilu. Konstante stabilnosti nastalih kompleksa određene su metodama 1H NMR spektroskopije, spektrofluorimetrije i spektroskopije cirkularnog dikroizma. Strukturne karakteristike anionskih kompleksa oba receptora istražene su simulacijama molekulske dinamike. Rezultati upućuju na to da su anioni koordinirani pomoću amidnih i amino protona peptida. Većina nastalih kompleksa je stehiometrije 1:1, osim u slučaju dihidrogenfosfata kod kojeg je uočena i stehiometrija 1:2 (receptor:anion)

Abstract (english)

Cyclic peptides represent a particularly interesting class of supramolecular anion receptors due to their diversity and good complexation properties. The first step in the synthesis of cyclic peptides is the preparation of their linear analogues after which the cyclization is carried out. The most important factor for a successful cyclization is the conformational reorganization of the linear peptide, in which the N and C reactive ends approach each other. Reorganization can be enhanced using templating ions. In this work, the complexation of methyl esters of linear tetra and hexaphenylalanine with halide and oxoanions in acetonitrile was investigated. The stability constants of corresponding complexes were determined by 1H NMR spectroscopy, spectrofluorimetry and circular dichroism spectroscopy. The structural characteristics of the anionic complexes of both receptors were investigated by molecular dynamics simulations as well. The results indicate that the anions are coordinated by the amide and amino protons of the peptide. Most of the resulting complexes are of 1:1 stoichiometry, except in the case of dihydrogen phosphate, where a 1:2 stoichiometry (receptor:anion) was also observed.

• Keywords: 1H NMR; cirkularni dikroizam; fluorimetrija; kompleksiranje aniona; linearni peptidi; molekulska dinamik
• Keywords (english): 1H NMR; anion complexation; circular dichroism; fluorimetry; linear peptides; molecular dynamics
• Language: croatian
• URN:NBN: urn:nbn:hr:217:177772
• Project: Number: IP-2019-04-9560; Title: Koordinacijske reakcije makrocikličkih liganada u otopini; Title: Coordination Reactions of Macrocyclic Ligands in Solution; Acronym: MacroSol; Leader: Vladislav Tomišić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-05-31
• Created on: 2023-06-09 08:52:33