Preparation and evaluation of L- and D-5-[ 18 F]fluorotryptophan as PET imaging probes for indoleamine and tryptophan 2,3-dioxygenases
作者:Tang Tang、Herman S. Gill、Annie Ogasawara、Jeff N. Tinianow、Alexander N. Vanderbilt、Simon-Peter Williams、Georgia Hatzivassiliou、Sharla White、Wendy Sandoval、Kevin DeMent、Mengling Wong、Jan Marik
DOI:10.1016/j.nucmedbio.2017.05.001
日期:2017.8
Indoleamine and tryptophan 2,3-dioxygenases (IDO1 and TDO2) are pyrrolases catalyzing the oxidative cleavage of the 2,3-double bond of L-tryptophan in kynurenine pathway. In the tumor microenvironment, their increased activity prevents normal immune function, i.e. tumor cell recognition and elimination by cytotoxic T-cells. Consequently, inhibition of the kynurenine pathway may enhance the activity
吲哚胺和色氨酸的2,3-二加氧酶(IDO1和TDO2)是催化犬尿氨酸途径中L-色氨酸的2,3-双键氧化裂解的吡咯酶。在肿瘤微环境中,它们增加的活性阻止了正常的免疫功能,即肿瘤细胞对细胞毒性T细胞的识别和清除。因此,抑制犬尿氨酸途径可以通过逆转免疫功能障碍来增强癌症免疫疗法的活性。我们试图研究放射性标记的5- [18F]氟色氨酸通过正电子发射断层扫描(PET)测量IDO1和TDO2活性的性能。结果通过Cu(I)催化Boc / tBu保护的前体的[18F]氟脱硼烷基化反应,以中等收率(1.5±0)合成了L-5- [18F]氟色氨酸和D-5- [18F]氟色氨酸。6%)足以用于临床前研究。产品的比活为407-740GBq /μmol,放射化学纯度> 99%,对映体过量90-99%。酶促测定证实L-5-氟色氨酸是IDO1和TDO2底物,而D-异构体不是。使用CT26细胞与强力霉素诱导的人IDO1和