~3H-LABELLING OF SCOPOLAMINE AND THE LABELLING LOCATION

Scopolamine is an important anaesthetic. ~3H-scopolamine was prepared by Wilzbach tritium gas-exposure method for the study of its pharmacokneties. The total radioactivity of ~3H-scopolamine was 61.8 MBq, radiochemical purity was 97%,and specific activity was 3.9 MBq/ mg. The location of ~3H-labelling was studied by calculating the superdelocalizability S_r(E) by CNDO/2 method. The calculated results agreed with experimental values by chemical dissociation method. The calculations showed that ~3H of tropic acid is 72% that of ~3H-scopolamine. As can be seen, the location of ~3H-labelling is mainly on the tropic acid.