| 摘要 |
<p>DIGOXIN DERIVATIVES Lysyl tyrosine methyl ester can be coupled to digoxin (digoxigenin tridigitoxoside) by reacting the .epsilon.-amino group of the lysine residue with the opened terminal sugar group of digoxin to yield a new digoxin derivative. The derivative can be labelled at the benzyl ring of the tyrosine residue with 125I to space the label away from the antigenic moiety of the digoxin derivative. The spaced label minimizes deleterious effects of gamma radiation on the antigenic moiety, yields a labelled digoxin derivative having an affinity for antidigoxin antibodies about equal to that of unlabelled digoxin, and facilitates the radioimmunoassay of digoxin using gamma scintillation counters.</p> |
