PREPARATION AND BIOLOGICAL EVALUATION OF AN ASTATINE-211 LABELED BIOTIN CONJUGATE - BIOTINYL-3-[AT-211]ASTATOANILIDE

Biotinyl-3-[At-211]astatoanilide ([At-211]AtBA) was prepared in more t han 80% yield by destannylation. In vitro, [At-211]AtBA exhibited a hi gh affinity for streptavidin, and was stable after incubation in human serum, cerebrospinal fluid and distilled water, whereas it was rapidl y degraded in mouse serum. HPLC analysis showed that the main degradat ion pathway in mouse serum was the cleavage of [At-211]astatoaniline. In mice, [At-211]AtBA and its I-125-labeled analogue cleared rapidly f rom most tissues; however, there was some evidence for dehalogenation of both tracers. (C) 1997 Elsevier Science Inc.