Description
PB28 is a potent, high affinity (Ki = 0.34 nM1) sigma2 agonist (1). Its antiproliferative (EC50 ~ 0.4uM) and cytotoxic (EC50 ~ 12uM) impacts on glioma and neuroblastoma cell lines suggest it is also a sigma1 antagonist (2). PB28 also stopped cell growth in MCF7 breast cancer lines, and was synergistic with doxorubicin (3). PB28 also inhibited Kv2.1 channels in a sigma-independent manner, suggesting it may be seen in future Alzheimer's and diabetes research (4). Recently, PB28 showed potent (IC50 = 280 nM; 20-fold more than hydroxychloroquine) anti-SARS-CoV2 activity, without cardiac side effects (5,6)