The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Dae Hyuk Moon - One of the best experts on this subject based on the ideXlab platform.
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new automated synthesis of 18f fp cit with base amount control affording high and stable Radiochemical Yield a 1 5 year production report
Nuclear Medicine and Biology, 2011Co-Authors: Sang Ju Lee, Dae Hyuk Moon, Dae Yoon Chi, Jae Seung Kim, Woo Yeon Moon, Moon Seok Choi, Jin-sook RyuAbstract:Abstract We describe new [ 18 F]Fluoropropylcarbomethoxyiodophenyl-nor-tropane ([ 18 F]FP-CIT) automatic preparation method by (1) using 2-methyl-2-butanol as [ 18 F]fluorination solvent, (2) base amount control to minimize side reaction and (3) salt elution method to elute trapped [ 18 F]fluoride. We developed manual synthesis procedures for automatic synthesis application. In this manual synthesis, we trapped [ 18 F]F − on ion exchange cartridge and eluted with 0.2 M potassium methanesulfonate solution. We have [ 18 F]fluorination at 100°C with 2-methyl-2-butanol as protic solvent for [ 18 F]fluorination. After high-performance liquid chromatography analysis, we have 69.3±3.2% of [ 18 F]F − incorporation ratio on the manual synthesis and applied these conditions to automatic preparation with GE TracerLab FX module. After setting-up of automatic synthesis and quality control procedures for clinical procedures, we have routine production of [ 18 F]FP-CIT with 86.9±9.5 GBq/2.5 ml of [ 18 F]F − as initial radioactivity and have 192 productions for 1.5 year. We have 42.5±10.9% of decay corrected Radiochemical Yields and they were satisfied all quality control procedures and stability to 6 h. New [ 18 F]FP-CIT automatic preparation method showed high and reliable Radiochemical Yield and we could have enough >35 patient doses of [ 18 F]FP-CIT from one production.
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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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Simple and High Radiochemical Yield synthesis of 2' -Deoxy -2' -[18F]fluorouridine via a new nosylate precursor
Journal of Labelled Compounds and Radiopharmaceuticals, 2006Co-Authors: Hun Kang, Mi Kyung Yoon, Jin-sook Ryu, Won Koo Lee, Sun Joo Choi, Kyung Pae Park, Dae Hyuk MoonAbstract:We synthesized 2'-deoxy-2'-[18F]fluorouridine (7) as a radiotracer for positron emission tomography from a new nosylate precursor (6). This new precursor was synthesized from uridine in four steps. The overall synthetic Yield was 9.4% and we have high stability of >98% purity up to 6 months at 4°C. The optimal manual [18F]fluorination conditions were 30 mg of the precursor 6 in 500 µl of acetonitrile at 145°C for 15 min with 370 MBq of [18F]fluoride. The [18F]fluorination Yield was 76.5±2.7% (n = 3). After hydrolysis of protecting groups with 1 N HCl and purification by HPLC, the overall Radiochemical Yield and purity were 26.5±1.4% and 98.2±2.5%, respectively. The preparation time was 70.0±10.5 min (n = 3 for each result). We also developed an automated method with a Radiochemical Yield and purity of 24.0±2.8 and 98.0±1.5% (n = 10) using a GE TracerLab MX chemistry module. This new nosylate precursor for 2'-deoxy-2'-[18F]fluorouridine synthesis showed higher Radiochemical Yields and reproducibility than previous methods. Copyright © 2006 John Wiley & Sons, Ltd.
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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%.
Ralf Schirrmacher - One of the best experts on this subject based on the ideXlab platform.
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synthesis of 3 chloro 6 4 di tert butyl 18f fluorosilyl benzyl oxy 1 2 4 5 tetrazine 18f sifa otz for rapid tetrazine based 18f radiolabeling
Chemical Communications, 2015Co-Authors: Jun Zhu, Carmen Wangler, Bjorn Wangler, Bruce R Lennox, Ralf SchirrmacherAbstract:An efficient method to prepare the 18F-labeled tetrazine-derivative [18F]-SiFA-OTz for bioorthogonal radiochemistry was developed. [18F]-SiFA-OTz can be synthesized with a Radiochemical Yield of 78 ± 5% within 25 min and can quantitatively react with a model strained dienophile, trans-cyclooctenol.
Dae Yoon Chi - One of the best experts on this subject based on the ideXlab platform.
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new automated synthesis of 18f fp cit with base amount control affording high and stable Radiochemical Yield a 1 5 year production report
Nuclear Medicine and Biology, 2011Co-Authors: Sang Ju Lee, Dae Hyuk Moon, Dae Yoon Chi, Jae Seung Kim, Woo Yeon Moon, Moon Seok Choi, Jin-sook RyuAbstract:Abstract We describe new [ 18 F]Fluoropropylcarbomethoxyiodophenyl-nor-tropane ([ 18 F]FP-CIT) automatic preparation method by (1) using 2-methyl-2-butanol as [ 18 F]fluorination solvent, (2) base amount control to minimize side reaction and (3) salt elution method to elute trapped [ 18 F]fluoride. We developed manual synthesis procedures for automatic synthesis application. In this manual synthesis, we trapped [ 18 F]F − on ion exchange cartridge and eluted with 0.2 M potassium methanesulfonate solution. We have [ 18 F]fluorination at 100°C with 2-methyl-2-butanol as protic solvent for [ 18 F]fluorination. After high-performance liquid chromatography analysis, we have 69.3±3.2% of [ 18 F]F − incorporation ratio on the manual synthesis and applied these conditions to automatic preparation with GE TracerLab FX module. After setting-up of automatic synthesis and quality control procedures for clinical procedures, we have routine production of [ 18 F]FP-CIT with 86.9±9.5 GBq/2.5 ml of [ 18 F]F − as initial radioactivity and have 192 productions for 1.5 year. We have 42.5±10.9% of decay corrected Radiochemical Yields and they were satisfied all quality control procedures and stability to 6 h. New [ 18 F]FP-CIT automatic preparation method showed high and reliable Radiochemical Yield and we could have enough >35 patient doses of [ 18 F]FP-CIT from one production.
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Highly efficient production of [18F]fallypride with low concentration of base
The Journal of Nuclear Medicine, 2010Co-Authors: Byung Seok Moon, Jun Hyung Park, Hong Jin Lee, Hee Sup Kil, Dae Yoon Chi, Byung Chul Lee, Yu Kyeong Kim, Sang Eun KimAbstract:1502 Objectives [18F]Fallypride exhibits an effective radiotracer for the study of dopamine D2/D3 receptor occupancy, neuropsychiatric disorders and aging in humans. However, automated labeling efficiency showed moderate Radiochemical Yields about 5-40% with relatively long incorporation time of fluorine-18, preceded high temperatures (150-165 °C) or involved the use of an unusual microwave system in automatic devices. In present study, we describe an automated Radiochemical synthesis of [18F]fallypride in different base concentration and incorporation time of fluorine-18 for potentially utilizable in routine production sites. Methods To minimization of base concentration of phase-transfer catalyst, [18F]fluoride was extracted with different concentrations of tetrabutylammonium bicarbonate (TBAHCO3) or Kryptofix 2.2.2./K2CO3 in organic solvent such as CH3CN/H2O or MeOH/H2O from 18O-enriched water trapped on the activated ion exchange cartridge (Chromafix® PS-HCO3). After azeotropic drying, the labeling reaction proceeded in CH3CN at 100 °C for 10 or 30 min. The desired product, [18F]fallypride, was purified by reverse phase HPLC and collected solution was exchanged for 10% ethanol in saline using tC18 Sep-Pak for clinical research. Results The Radiochemical Yield was increased according to decreasing amounts of base concentration. The labeling condition of [18F]fallypride was optimized that 2 mg of tosyl-fallypride in acetonitrile (1 mL) was heated at 100 °C for 10 min with 40% TBAHCO3 (10 μL). [18F]Fallypride was obtained with high Radiochemical Yield about 68 ± 1.6% (decay-corrected, n = 8) within 51 ± 1.2 min including HPLC purification and solid-phase purification. The specific activity showed about 140-192 GBq/μmol. Conclusions [18F]Fallypride was prepared with a significantly improved Radiochemical Yield with high specific activity and shorten synthetic time. This automated procedure for [18F]fallypride production could facilitate its routine clinical use in dopamine D2/D3 studies
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an efficient f 18 labeling method for pet study huisgen 1 3 dipolar cycloaddition of bioactive substances and f 18 labeled compounds
Tetrahedron Letters, 2007Co-Authors: Uthaiwan Sirion, Sang Ju Lee, Heejun Kim, Jae Hak Lee, Jai Woong Seo, Byoung Se Lee, Dae Yoon ChiAbstract:Abstract The Cu(I)-catalyzed, 1,3-dipolar cycloaddition reaction was applied successfully to the synthesis of small, F-18-labeled biomolecules, and an optimal condition was developed for one-pot, two-step reaction without any interim purifications. This technique was employed in various F-18-labeled, 1,2,3-triazole syntheses with high Radiochemical Yield.
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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.
S. N. Dmitriev - One of the best experts on this subject based on the ideXlab platform.
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a simple and quick method for the preparation of radionuclide 87y 87msr generator using the natrb α xn 87y reaction
Journal of Radioanalytical and Nuclear Chemistry, 2009Co-Authors: N. V. Aksenov, Ya G Starodub, H. Bruchertseifer, G. K. Vostokin, E. E. Tereshatov, G. A. Bozhikov, S. V. Shishkin, S. N. DmitrievAbstract:A rapid method for the preparation of 87Y/87mSr radionuclide generator from a rubidium chloride target irradiated with 35 MeV α-particles is described. A simple two-step procedure is used to obtain a carrier-free 87mSr isotope with a high enough Radiochemical Yield and high purity in the final aqueous fraction.
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A simple and quick method for the preparation of radionuclide 87Y/87mSr generator using the natRb(α,xn)87Y reaction
Journal of Radioanalytical and Nuclear Chemistry, 2008Co-Authors: N. V. Aksenov, G. Ya. Starodub, H. Bruchertseifer, G. K. Vostokin, E. E. Tereshatov, G. A. Bozhikov, S. V. Shishkin, S. N. DmitrievAbstract:A rapid method for the preparation of 87Y/87mSr radionuclide generator from a rubidium chloride target irradiated with 35 MeV α-particles is described. A simple two-step procedure is used to obtain a carrier-free 87mSr isotope with a high enough Radiochemical Yield and high purity in the final aqueous fraction.
Sang Ju Lee - One of the best experts on this subject based on the ideXlab platform.
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new automated synthesis of 18f fp cit with base amount control affording high and stable Radiochemical Yield a 1 5 year production report
Nuclear Medicine and Biology, 2011Co-Authors: Sang Ju Lee, Dae Hyuk Moon, Dae Yoon Chi, Jae Seung Kim, Woo Yeon Moon, Moon Seok Choi, Jin-sook RyuAbstract:Abstract We describe new [ 18 F]Fluoropropylcarbomethoxyiodophenyl-nor-tropane ([ 18 F]FP-CIT) automatic preparation method by (1) using 2-methyl-2-butanol as [ 18 F]fluorination solvent, (2) base amount control to minimize side reaction and (3) salt elution method to elute trapped [ 18 F]fluoride. We developed manual synthesis procedures for automatic synthesis application. In this manual synthesis, we trapped [ 18 F]F − on ion exchange cartridge and eluted with 0.2 M potassium methanesulfonate solution. We have [ 18 F]fluorination at 100°C with 2-methyl-2-butanol as protic solvent for [ 18 F]fluorination. After high-performance liquid chromatography analysis, we have 69.3±3.2% of [ 18 F]F − incorporation ratio on the manual synthesis and applied these conditions to automatic preparation with GE TracerLab FX module. After setting-up of automatic synthesis and quality control procedures for clinical procedures, we have routine production of [ 18 F]FP-CIT with 86.9±9.5 GBq/2.5 ml of [ 18 F]F − as initial radioactivity and have 192 productions for 1.5 year. We have 42.5±10.9% of decay corrected Radiochemical Yields and they were satisfied all quality control procedures and stability to 6 h. New [ 18 F]FP-CIT automatic preparation method showed high and reliable Radiochemical Yield and we could have enough >35 patient doses of [ 18 F]FP-CIT from one production.
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an efficient f 18 labeling method for pet study huisgen 1 3 dipolar cycloaddition of bioactive substances and f 18 labeled compounds
Tetrahedron Letters, 2007Co-Authors: Uthaiwan Sirion, Sang Ju Lee, Heejun Kim, Jae Hak Lee, Jai Woong Seo, Byoung Se Lee, Dae Yoon ChiAbstract:Abstract The Cu(I)-catalyzed, 1,3-dipolar cycloaddition reaction was applied successfully to the synthesis of small, F-18-labeled biomolecules, and an optimal condition was developed for one-pot, two-step reaction without any interim purifications. This technique was employed in various F-18-labeled, 1,2,3-triazole syntheses with high Radiochemical Yield.
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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.
