Retention of [18F]fluoride on reversed phase HPLC columns

Ory, Dieter; Brande, Jeroen Van den; Groot, Tjibbe de; Serdons, Kim; Bex, Marva; Declercq, Lieven; Cleeren, Frederik; Ooms, Maarten; Laere, Koen Van; Verbruggen, Alfons; Bormans, Guy

doi:10.1016/j.jpba.2015.04.009

Cited by 46 publications

(33 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The very low [ 18 F] concentration requires a high substrate concentration, and the low solubility of 4 a and 4 b in 5 % DMSO limited their reaction concentrations to 0.15 and 0.48 m m , respectively. The conversion of 18 F − into 5 a and 5 b was only modest (Supporting Information, Figures S4 and S5, based on the integration of the peaks of product and unreacted 18 F − ion by HPLC). Substrate 4 d , has good solubility but proved to be hydrolytically unstable (Figure , bottom HPLC trace shows a degraded product at 13.2 min) relative to 4 a – c , and 5 d visibly decomposed on work up, therefore radiochemical trials were not explored further with this substrate.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Last‐Step Enzymatic [¹⁸F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Zhang

Dall’Angelo

Fleming

et al. 2016

Chemistry A European J

View full text Add to dashboard Cite

Abstract:We report a last-step fluorinase catalyzed [ 18 F]-fluorination of a cysteine-containing RGD peptide. The peptide was attached through sulfur to a modified and more hydrophilic variant of the recently disclosed Barbas linker which was itself linked to a chloroadenosine moiety via a PEGylated chain. The fluorinase was able to use this construct as a substrate for a transhalogenation reaction to generate [ 18 F]-radiolabelled RGD peptides, which retained high affinity to cancer cell relevant α v β 3 integrins

show abstract

Section: Resultsmentioning

confidence: 99%

“…≤0.66 m m ) to [ 18 F] 5 c (final conc. of DMSO 2 %, Supporting Information, Figure S6) was accomplished (87 % by HPLC) . At 2 % DMSO, the enzyme precipitated cleanly after heat denature without gel formation.…”

Section: Resultsmentioning

confidence: 99%

Last‐Step Enzymatic [¹⁸F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Zhang

Dall’Angelo

Fleming

et al. 2016

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…For samples comprising crude reaction products, this amount of radioactivity also includes any impurities that may be present in the crude mixture (e.g., unreacted [ 18 F]fluoride and other 18 F-labeled species); therefore, the radioactivity amount was further corrected by multiplying by the radiochemical purity (RCP) of the desired species. Because of known losses of [ 18 F]fluoride in HPLC columns 52 , the radiochemical purity was determined via a two-step process. (i) Radio-TLC analysis of the sample yielded a chromatogram with two peaks: one (R f = 0.0) representing unreacted [ 18 F]fluoride, and the other (R f =~0.75 for fallypride, R f =~0.8 for FNB) representing the radiofluorinated product (plus other potential fluorinated impurities).…”

Section: Methodsmentioning

confidence: 99%

Performing radiosynthesis in microvolumes to maximize molar activity of tracers for positron emission tomography

et al. 2018

View full text Add to dashboard Cite

Positron emission tomography (PET) is a molecular diagnostic imaging technology to quantitatively visualize biological processes in vivo. For many applications, including imaging of low-tissue density targets (e.g., neuroreceptors), imaging in small animals, and evaluation of novel tracers, the injected PET tracer must be produced with high molar activity to ensure low occupancy of biological targets and avoid pharmacologic effects. Additionally, high molar activity is essential for tracers with lengthy syntheses or tracers transported to distant imaging sites. Here we show that radiosynthesis of PET tracers in microliter volumes instead of conventional milliliter volumes results in substantially increased molar activity, and we identify the most relevant variables affecting this parameter. Furthermore, using the PET tracer [ 18 F]fallypride, we illustrate that molar activity can have a significant impact on biodistribution. With full automation, microdroplet platforms could provide a means for radiochemists to routinely, conveniently, and safely produce PET tracers with high molar activity.

show abstract

“…[ 18 F]ESF, we studied its utilisation in conjugation reactions with selected AA analogues and aniline ( Figure 2) in various solvents. Radio-TLC and Radio-HPLC were both used to measure conjugation RCY and the results were comparable; 22 however, we chose Radio-HPLC to assess conjugation efficiency as it allows the measurement of both unreacted [ 18 F]ESF and [ 18 F]fluoride. In a first set of reactions utilising AA at 1 mg/mL concentration, all the HPLC vials were queued for overnight analysis to get quick proof of principle results; in this case, the reaction time was not controlled and could be up to 8 h (complete data reported in SI).…”

Section: Conjugation Of [ 18 F]esfmentioning

confidence: 99%

Synthesis, bioconjugation and stability studies of [¹⁸F]ethenesulfonyl fluoride

Zhang

Pascali

Wyatt

et al. 2018

Labelled Comp Radiopharmac

View full text Add to dashboard Cite

Fluorine-18 labelled prosthetic groups (PGs) are often necessary for radiolabelling sensitive biological molecules such as peptides and proteins. Several shortcomings, however, often diminish the final yield of radiotracer. In an attempt to provide higher yielding and operationally efficient tools for radiolabelling biological molecules, we describe herein the first radiochemical synthesis of [ F]ethenesulfonyl fluoride ([ F]ESF) and its Michael conjugation with amino acids and proteins. The synthesis of [ F]ESF was optimised using a microfluidic reactor under both carrier-added (c.a.) and no-carrier-added (n.c.a.) conditions, affording, in a straightforward procedure, 30-50% radiochemical yield (RCY) for c.a. [ F]ESF and 60-70% RCY for n.c.a. [ F]ESF. The conjugation reactions were performed at room temperature using 10 mg/mL precursor in aqueous/organic solvent mixtures for 15 min. The radiochemical stability of the final conjugates was evaluated in injectable formulation and rat serum, and resulted strongly substrate dependent and generally poor in rat serum. Therefore, in this work we have optimised a straightforward synthesis of [ F]ESF and its Michael conjugation with model compounds, without requiring chromatographic purification. However, given the general low stability of the final products, further studies will be required for improving conjugate stability, before assessing the use of this PG for PET imaging.

show abstract

Retention of [18F]fluoride on reversed phase HPLC columns

Cited by 46 publications

References 9 publications

Last‐Step Enzymatic [¹⁸F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Last‐Step Enzymatic [¹⁸F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Performing radiosynthesis in microvolumes to maximize molar activity of tracers for positron emission tomography

Synthesis, bioconjugation and stability studies of [¹⁸F]ethenesulfonyl fluoride

Contact Info

Product

Resources

About

Retention of [18F]fluoride on reversed phase HPLC columns

Cited by 46 publications

References 9 publications

Last‐Step Enzymatic [18F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Last‐Step Enzymatic [18F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Performing radiosynthesis in microvolumes to maximize molar activity of tracers for positron emission tomography

Synthesis, bioconjugation and stability studies of [18F]ethenesulfonyl fluoride

Contact Info

Product

Resources

About

Last‐Step Enzymatic [¹⁸F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Last‐Step Enzymatic [¹⁸F]‐Fluorination of Cysteine‐Tethered RGD Peptides Using Modified Barbas Linkers

Synthesis, bioconjugation and stability studies of [¹⁸F]ethenesulfonyl fluoride