A labeled immunosuppressant that blocks T cell proliferation in vitro by inhibiting the generation of several lymphokines, especially IL-2. Shown to inhibit the activity of FK-506 binding protein, thereby reversing its effects on sarcoplasmic reticulum Ca+2 release. A representative lot contained a distribution of 20% d-1, 40% d-2 and 20% d-3.Form:White to Off-White SolidMelting Point:90-92°CSolubility:Chloroform, Methanol