This letter describes the synthesis, structure-activity relationships, and in vivo evaluation of the new series selleckchem of 2-phenylquinoxaline Tamoxifen (PQ) derivatives for imaging beta-amyloid (A beta) plaques in Alzheimer's condition (AD). In experiments in vitro, the affinity on the derivatives for any beta aggregates varied, with K-i values of 0.895 to 1180 nM. In brain sections from AD individuals, derivatives using a K-i of less than 111 nM intensely labeled A beta plaques, though individuals with values in excess of 242 nM showed no marked labeling. In biodistribution experiments utilizing typical www.selleckchem.com/products/Abiraterone.html mice, the derivatives showed good uptake into (4-69-7.59 %ID/g at 2 or 10 min postinjection) and subsequent washout from (1.48-3.08 %ID/g at 60 mm postinjection) the brain. Also, [F-18]PQ-6 labeled A beta plaques in vivo in APP transgenic mice, even though it showed nonspecific binding inside the white matter. Additional structural optimization based upon [F-18]PQ-6 may possibly lead to a lot more practical PET probes for imaging A beta plaques.