1-[2-[4-(phenylmethyl)phenoxy]ethyl]-Pyrrolidine hydrochloride

PBPE hydrochloride is a derivative of tamoxifen (HY-13757A) and a selective ligand for the anti-estrogen binding site (AEBS), the binding affinities (Ki) of PBPE hydrochloride and MBPE to AEBS are 8.79 and 17.57 nM, respectively[1][2].

[1] B Kedjouar, et al. Structural similitudes between cytotoxic antiestrogen-binding site (AEBS) ligands and cytotoxic sigma receptor ligands. Evidence for a relationship between cytotoxicity and affinity for AEBS or sigma-2 receptor but not for sigma-1 receptor. Biochem Pharmacol. 1999 Dec 15;58(12):1927-39. DOI:10.1016/s0006-2952(99)00285-3
[2] Florence Dalenc, et al. Farnesyl-transferase inhibitor R115,777 enhances tamoxifen inhibition of MCF-7 cell growth through estrogen receptor dependent and independent pathways. Breast Cancer Res. 2005;7(6):R1159-67. DOI:10.1186/bcr1357