Penicillamine \Pen`i*cil"lam*ine\, n. (Chem., Med.)
A substance ({C5H11NO2S}) which is a degradation product of
the penicillins. Chemically it is 3-mercapto-D-valine. It has
chelating properties and is used in medicine as an
antirheumatic and to chelate copper in cases of
hepatolenticular degeneration (Wilson's disease).
[PJC]