The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jongho Jeon - One of the best experts on this subject based on the ideXlab platform.
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development of a new thiol reactive prosthetic group for site specific labeling of biomolecules with radioactive iodine
Bioorganic & Medicinal Chemistry Letters, 2018Co-Authors: Ha Eun Shim, Sajid Mushtaq, Lee Song, Chang Heon Lee, Hyosun Lee, Jongho JeonAbstract:In this report, we describe the radiosynthesis of a new thiol-targeting prosthetic group for efficient radioactive iodine labeling of biomolecules. Radioiodination using the precursor 3 was performed to obtain 125I-labeled tetrazole 4b with high radiochemical yield (73%) and radiochemical purity. Using the radiolabeled 4b, a single free cysteine containing peptide and human serum albumin were labeled with 125I in modest-to-good radiochemical yields (65-99%) under mildly reactive conditions. A biodistribution study of [125I]7 in normal ICR mice exhibited lower thyroid uptake values than those of 125I-labeled human serum albumin prepared via a traditional radiolabeling method. Thus, [125I]7 could be employed as an effective radiotracer for molecular imaging and biodistribution studies. The results clearly demonstrate that 4b has the potential to be effectively implemented as a prosthetic group in the preparation of radiolabeled biomolecules.
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synthesis and evaluation of an 125 i labeled azide prosthetic group for efficient and bioorthogonal radiolabeling of cyclooctyne group containing molecules using copper free click reaction
Bioorganic & Medicinal Chemistry Letters, 2016Co-Authors: Mi Hee Choi, Jung Ae Kang, Ha Eun Shim, You Ree Nam, Hye Rim Kim, Dae Seong Choi, Sang-hyun Park, Beom-su Jang, Dongeun Lee, Jongho JeonAbstract:Herein we report the radiosynthesis of a pyridine derived azide prosthetic group for iodine radioisotope labeling of dibenzocyclooctyne (DBCO) conjugated molecules. The radiolabeling of the stannylated precursor 2 was conducted using [(125)I]NaI and chloramine-T to give (125)I-labeled azide ([(125)I]1) with high radiochemical yield (72±8%, n=4) and radiochemical purity (>99%). Using (125)I-labeled azide ([(125)I]1), cyclic RGD peptide and near infrared fluorescent molecule were efficiently labeled with modest to good radiochemical yields. The biodistribution study and SPECT/CT images showed that [(125)I]1 underwent rapid renal clearance. These results clearly demonstrated that [(125)I]1 could be used as an useful radiotracer for in vivo pre-targeted imaging as well as efficient in vitro radiolabeling of DBCO containing molecules.
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efficient method for site specific 18f labeling of biomolecules using the rapid condensation reaction between 2 cyanobenzothiazole and cysteine
Bioconjugate Chemistry, 2012Co-Authors: Jongho Jeon, Liqin Xiong, Bin Shen, Zheng Miao, Frederick T ChinAbstract:An efficient method based on a rapid condensation reaction between 2-cyanobenzothiazole (CBT) and cysteine has been developed for 18F-labeling of N-terminal cysteine-bearing peptides and proteins. An 18F-labeled dimeric cRGD ([18F]CBTRGD2) has been synthesized with an excellent radiochemical yield (92% based on radio-HPLC conversion, 80% decay-corrected, and isolated yield) and radiochemical purity (>99%) under mild conditions using 18F-CBT, and shown good in vivo tumor targeting efficiency for PET imaging. The labeling strategy was also applied to the site-specific 18F-labeling of a protein, Renilla lucifierase (RLuc8) with a cysteine residue at its N-terminus. The protein labeling was achieved with 12% of decay-corrected radiochemical yield and more than 99% radiochemical purity. This strategy should provide a general approach for efficient and site-specific 18F-labeling of various peptides and proteins for in vivo molecular imaging applications.
Dae Hyuk Moon - One of the best experts on this subject based on the ideXlab platform.
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one step high radiochemical yield synthesis of 18f fp cit using a protic solvent system
Nuclear Medicine and Biology, 2007Co-Authors: Sang Ju Lee, Dae Yoon Chi, Se Hun Kang, Hee Seup Kil, Jae Seung Kim, Dae Hyuk MoonAbstract:Although [18F] fluoropropylcarbomethoxyiodophenylnortropane (FP-CIT) is a promising radiopharmaceutical for dopamine transporter imaging, it has not been used for clinical studies because of low radiochemical yield. The purpose of our study was to develop a new radiochemistry method using a protic solvent system to obtain a high radiochemical yield of [18F]FP-CIT in single-step manual and automatic preparation procedures. [18F]F(-) was trapped on a QMA Sep-Pak cartridge or PS-HCO(3) cartridge and eluted with Cs2CO(3)/K222 buffer or TBAHCO3 respectively, or 8 microl of TBAOH was added directly to [18F]F(-)/H(2)(18)O solution in a reactor without using a cartridge. After drying, 18F] fluorination was performed with 2-6 mg of mesylate precursor, 100 microl of CH(3)CN and 500 microl of t-BuOH at 50-120 degrees C for 5-30 min, followed by high-performance liquid chromatography (HPLC) purification to obtain the final product. For comparison, the same procedure was performed with a tosylate precursor. Manual synthesis gave a decay-corrected radiochemical yield of 52.2+/-4.5%, and optimal synthesis conditions were as follows: TBAOH addition, 4 mg of precursor, 100 degrees C and 20 min of [18F] fluorination (n=3). We obtained low radiochemical yields of [18F]FP-CIT with carbonate elution systems such as Cs2CO(3) or TBAHCO3. We also developed an automatic synthesis method based on manual synthesis results. In automatic production, we obtained a decay-corrected radiochemical yield of 35.8+/-5.2% after HPLC purification, and we did not have any synthesis failures (n=14). Here, we describe our new method for the synthesis of [18F]FP-CIT using a protic solvent system. This method gave a high radiochemical yield with high reproducibility and might enable [18F]FP-CIT to be used clinically and commercially.
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high radiochemical yield synthesis of 3 deoxy 3 18f fluorothymidine using 5 o dimethoxytrityl 2 deoxy 3 o nosyl β d threo pentofuranosyl thymine and its 3 n boc protected analogue as a labeling precursor
Nuclear Medicine and Biology, 2003Co-Authors: Mikyung Yun, Jin-sook Ryu, Dae Hyuk MoonAbstract:Abstract We prepared 3′-deoxy-3′-[ 18 F]fluorothymidine ([ 18 F]FLT) from 3′- O -nosyl thymidine derivative 3 or its pyrimidine ring N -BOC-protected analogue 5 and optimized [ 18 F]fluorination condition for a high radiochemical yield. The optimal condition for [ 18 F]fluorination with precursor 3 was 30 mg (41.1 μmol)/300 μl CH 3 CN at 130°C for 5 min, while precursor 5 required 34 mg (40 μmol)/300 μl CH 3 CN at 110°C for 5 min. After HPLC purification at neutral pH, we achieved high radiochemical yields of 40 ± 5.2% and 42 ± 5.4% (decay-corrected) within 60 min of preparation time with radiochemical purities of >97%.
David R Elmaleh - One of the best experts on this subject based on the ideXlab platform.
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selective monomethylation of the primary amine function using 11c ch3i and the n trifluoroacetyl derivative preparation of n 11c methyl chlorphentermine
Nuclear Medicine and Biology, 1993Co-Authors: H. Kizuka, David R ElmalehAbstract:Abstract A simple, rapid and efficient method for the preparation of a potential brain blood-flow agent, N -[ 11 C-methyl]-chlorphentermine ([ 11 C]NMCP), is described. Optimization of the radiochemical yield of [ 11 C]NMCP was accomplished by a Gabriel-like reaction which permits the transformation of a primary amine to a secondary amine through a sequence of acylation, deprotonation, monomethylation and saponification. This method precludes the formation of polymethylated by-products which can reduce radiochemical yields, particularly with low specific activity 11 CO 2 .
Mikyung Yun - One of the best experts on this subject based on the ideXlab platform.
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High radiochemical yield synthesis of 3Ј-deoxy-3Ј-[ 18 F]fluorothymidine using (5Ј-O-dimethoxytrityl-2Ј-deoxy-3Ј-O-nosyl--D-threo pentofuranosyl)thymine and its 3-N-BOC-protected analogue as a labeling precursor
2020Co-Authors: Mikyung Yun, Jin-sook Ryu, Hyuk MoonAbstract:Abstract We prepared 3Ј-deoxy-3Ј-[ 18 F]fluorothymidine ([ 18 F]FLT) from 3Ј-O-nosyl thymidine derivative 3 or its pyrimidine ring N-BOCprotected analogue 5 and optimized [ 18 F]fluorination condition for a high radiochemical yield. The optimal condition for [ 18 F]fluorination with precursor 3 was 30 mg (41.1 mol)/300 l CH 3 CN at 130°C for 5 min, while precursor 5 required 34 mg (40 mol)/300 l CH 3 CN at 110°C for 5 min. After HPLC purification at neutral pH, we achieved high radiochemical yields of 40 Ϯ 5.2% and 42 Ϯ 5.4% (decay-corrected) within 60 min of preparation time with radiochemical purities of Ͼ97%
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high radiochemical yield synthesis of 3 deoxy 3 18f fluorothymidine using 5 o dimethoxytrityl 2 deoxy 3 o nosyl β d threo pentofuranosyl thymine and its 3 n boc protected analogue as a labeling precursor
Nuclear Medicine and Biology, 2003Co-Authors: Mikyung Yun, Jin-sook Ryu, Dae Hyuk MoonAbstract:Abstract We prepared 3′-deoxy-3′-[ 18 F]fluorothymidine ([ 18 F]FLT) from 3′- O -nosyl thymidine derivative 3 or its pyrimidine ring N -BOC-protected analogue 5 and optimized [ 18 F]fluorination condition for a high radiochemical yield. The optimal condition for [ 18 F]fluorination with precursor 3 was 30 mg (41.1 μmol)/300 μl CH 3 CN at 130°C for 5 min, while precursor 5 required 34 mg (40 μmol)/300 μl CH 3 CN at 110°C for 5 min. After HPLC purification at neutral pH, we achieved high radiochemical yields of 40 ± 5.2% and 42 ± 5.4% (decay-corrected) within 60 min of preparation time with radiochemical purities of >97%.
Boris D Zlatopolskiy - One of the best experts on this subject based on the ideXlab platform.
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seyferth gilbert homologation as a route to 18f labeled building blocks preparation of radiofluor inated phenylacetylenes and their application in pet chemistry
European Journal of Organic Chemistry, 2016Co-Authors: Philipp Krapf, Raphael Richarz, Elizaveta A Urusova, Bernd Neumaier, Boris D ZlatopolskiyAbstract:A convenient method for the preparation of hitherto unknown ([18F]fluorophenyl)acetylenes ([18F]FPAs) using the Seyferth–Gilbert homologation is reported. The novel building blocks were efficiently prepared from easily accessible [18F]fluorobenzaldehydes by using the Bestmann–Ohira reagent. High radiochemical yields and excellent radiochemical purities were achieved within only 20 min of reaction time; 2- and 4-[18F]FPAs were applied to prepare radiofluorinated heterocycles by using different cycloaddition and cross-coupling reactions. Additionally, these building blocks were used to prepare three novel PET tracers. Thus, an artificial radiofluorinated protected amino acid [18F]10, a COX-2-specific ligand [18F]14, and a PSMA-selective inhibitor [18F]16 were obtained in high radiochemical yields.