Formulation: A solid
Formal Name: (11β,17β)-17-hydroxy-11-[4-(methylamino)phenyl]-17-(1-propyn-1-yl)-estra-4,9-dien-3-one
Purity: ≥98%
Formula Markup: C28H33NO2
Formula Weight: 415,6
Shelf life (days): 1460
CAS Number: 104004-96-8
Notes: Metapristone is an active metabolite of the glucocorticoid, progesterone, and androgen receptor antagonist mifepristone (Item No. 10006317).{65655} It is formed from mifepristone by the cytochrome P450 (CYP) isoform CYP3A4. Metapristone is an antagonist of human glucocorticoid and progesterone receptors with relative affinities of 61 and 21%, respectively, compared to mifepristone.{65656} It decreases the proliferation of A375 human and B16/F10 murine melanoma cells (IC50s = 57.4 and 75.8 µM, respectively).{65657} It induces cell cycle arrest at the G1 phase in B16/F10 cells when used at a concentration of 80 µM. Metapristone (2.5, 10, and 50 mg/kg per day) decreases the number of lung metastases in a B16/F10 murine model of lung metastasis.{65658}