RB-005 is a potent sphingosine kinase isoform 1 (SK1) inhibitor, which may serve as therapeutic agent for proliferative diseases, including hypertension. RB-005, (IC(50) = 3.6 μM), which also induced proteasomal degradation of SK1 in human pulmonary arterial smooth muscle cells.
K145 is inactive against SphK1 and other protein kinases. K145 induces cell apoptosis and has potently antitumor activity. K145 is a selective, substrate-competitive and orally active SphK2 inhibitor with an IC50 of 4.3 µM and a Ki of 6.4 µM.
SLP120701 is a potent and selective sphingosine kinase 2 inhibitor. Sphingosine-1-phosphate (S1P) is a ubiquitous, endogenous small molecule that is synthesized by two isoforms of sphingosine kinase (SphK1 and 2). Intervention of the S1P signaling pathway has attracted significant attention because alteration of S1P levels is linked to several disease states including cancer, fibrosis, and sickle cell disease.