Ulipristal acetate

White to light yellow crystalline powder. Soluble in DMSO (30mg/ml), ethanol (30mg/ml) or DMF (30mg/ml). Chemical. CAS: 126784-99-4. Formula: C30H37NO4. MW: 475.62. Synthetic. Ulipristal acetate is a selective progesterone receptor modulator (SPRM) that binds to the human progesterone receptors PR-A and PR-B (EC50s=8.5 and 7.7nM, respectively), rabbit uterine PR (EC50=13.6nM), and rabbit thymic glucocorticoid receptor (GR, EC50=15.4nM). It is selective for human progesterone receptors over the human estrogen receptor (ER, EC50>10,000nM). It inhibits growth of IGROV-1 and SKOV3 human ovarian cancer cells (IC50s=15.5 and 31.5µM, respectively) even after resistance to combined cisplatin and paclitaxel treatment has developed. Ulipristal acetate reverses the proliferative effect of progesterone on patient-derived germline mutant BRCA1 breast tissue xenografts in ovariectomized athymic mice. Formulations containing ulipristal acetate have been used as emergency contraceptives and to treat uterine fibroids.