IOCB Prague

Synthesis of Radiolabeled Compounds

Aleš Marek Group
Core Facility
CHEM cluster

About our group

Radioactive labels used for tracing of studied ligands have long been a part of the biochemical laboratory repertoire. Radioactivity gives a clear, unmistakable signal, and its use is fairly straightforward. We are devoted to supply radioactively labeled compounds to biochemical research teams of the institute, provide radiometric services, conduct radioactive waste management and supervise radiation safety rules within the institute.

We use optimized low-cost labeling procedure of peptides/polypeptides with IODO–GEN™– Na[125I] system. Produced are purified mono-iodinated peptides with specific activities over 2 000 Ci/mmol, separated from over-iodinated and starting peptides using radio-HPLC. Lyophilized 125I-labeled peptides can be stored at -20 °C for a long period of time.

Tritium/carbon-14 labeling of complex, multifunctional drug candidates requires mild, fast and safe preparative methods. We have expertise handling well-established methods used for introduction of tritium into biologically active molecules – from simple catalytic hydrogen isotope exchange through reduction of carbon-carbon multiple bonds, catalytic reductive dehalogenations to reductions with in-house synthesized carrier-free complex metallic tritides. We have been investigating the feasibility of Frustrated Lewis Pairs (FLP) as a mild catalysts for various tritiations in the quest for alternative orthogonal tritiation methods. The analysis and radiochemical purity of produced tracers is always checked by radio-HPLC, LC-MS, GC-MS, radio-TLC and 3H NMR spectra.



All publications
The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2′-Deoxyadenosine
The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2′-Deoxyadenosine
Journal of Physical Chemistry A 125 (1): 338–348 (2021)
Noncanonical nucleobases and nucleosides represent newly discovered species of relevance for DNA ionization. We report a targeted synthesis of gas-phase 9-methylene(1H)adenine cation radical (2) as a low-energy isomer of ionized 9-methyladenine. Ion 2 showed unique collision-induced dissociation and UV–vis photodissociation action spectra that distinguished it from other cation radical isomers. Ab initio energy calculations with coupled cluster theory extrapolated to the complete basis set limit, CCSD(T)/CBS, identified cation radical 2 as the global energy minimum of the adenine-related C6H7N5 isomers. The action spectrum of 2 was assigned on the basis of vibronic absorption spectra that were calculated with time-dependent density functional theory for multiple vibrational configurations of thermal ions. The major dissociation of 2 proceeded by hydrogen loss that was elucidated by deuterium labeling at the exchangeable N-1 and NH2 positions and C-8 position and by kinetic…
Iodination of CART(61‐102) peptide: Preserved binding and anorexigenic activity in mice
Journal of Labelled Compounds and Radiopharmaceuticals 64 (2): 61-64 (2021)
Tackling a Curious Case: Generation of Charge-Tagged Guanosine Radicals by Gas-Phase Electron Transfer and Their Characterization by UV–vis Photodissociation Action Spectroscopy and Theory
Journal of the American Society for Mass Spectrometry 32 (3): 772–785 (2021)
Radiolabeled HOCPCA as a highly useful tool in drug discovery and pharmacology
Journal of Labelled Compounds and Radiopharmaceuticals 64 (2): 77-81 (2021)