C 18 light sep pak cartridges

[¹⁸F]PARPi was synthesized using an optimized labeling procedure. No-carrier-added (n.c.a.) [¹⁸F]fluoride was obtained via the ¹⁸O(p,n)¹⁸F nuclear reaction of 16.5-MeV protons in an GE Healthcare PETTrace 800 using enriched ¹⁸O-water. QMA light ion-exchange cartridges and C-18 light Sep-Pak cartridges were obtained from Waters (Milford, MA). A QMA cartridge containing cyclotron-produced [¹⁸F] fluoride ion (50 mCi, 1.85 GBq) was eluted with a solution containing 9 mg Kryptofix [2.2.2] (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane), 0.08 mL 0.15 M K2CO3 and 1.92 mL MeCN into a 5 mL reaction vial. Solvents were removed azeotropically at 120 °C under N₂. Afterwards, 500 µg of ethyl 4-nitrobenzoate in 100 µL of dry DMSO was added and the mixture was heated to 150 °C for 15 min. 50 µL of 1 M NaOH was then added followed by 50 µL of 1 M HCl. Then, 2 mg of 4-(4-fluoro-3-(piperazine-1-carbonyl)benzyl)phthalazin-1(2H)-one in 100 µL of dry DMSO was added followed by 10 mg of HBTU dissolved in 100 µL of DMSO and 20 µL of Et₃N. 400 µL of MeCN and 1 mL H₂O were then added to the mixture and the product was purified by HPLC (Method A, t_R = 32 min) yielding (n.d.c) 38.4 ± 2.5% with a SA of 0.97 Ci/µmol.

ApoE^–/– mice were purchased from Qingzilan Technology Co., Ltd. (Nanjing, China), and New Zealand rabbits were acquired from Fuwai Hospital (Beijing, China). C-¹⁸ light Sep-Pak cartridges and QMA light ion-exchange cartridges were obtained from Waters (Milford, MA, United States). The ¹⁸F isotope was acquired through Jiangsu Huayi Technology Co., Ltd. (Changshu, China).
The scaffolds and ¹⁸F-labeled ASEM were synthesized and followed the descriptions in several previous studies (Gao et al., 2013 (link); Wang et al., 2021 (link)). Briefly, the ortho-substitution amino was countered with nucleophilic radio-fluorination in the last Sandmeyer reaction. Then, the product was purified by high-performance liquid chromatography (HPLC) and diluted through a C¹⁸ column. The radiochemical purity was > 99%.