Preferred IUPAC name
2-(Diethylamino)ethyl 2,2-diphenylpentanoate
Other names
SKF 525-A
3D model (JSmol)
  • InChI=1S/C23H31NO2/c1-4-17-23(20-13-9-7-10-14-20,21-15-11-8-12-16-21)22(25)26-19-18-24(5-2)6-3/h7-16H,4-6,17-19H2,1-3H3
  • O=C(OCCN(CC)CC)C(c1ccccc1)(c2ccccc2)CCC
Molar mass 353.506 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Proadifen (SKF-525A) is a non-selective inhibitor of cytochrome P450 enzymes, preventing some types of drug metabolism.[1] It is also an inhibitor of neuronal nitric oxide synthase (NOS), CYP-dependent (cytochrome P450-dependent) arachidonate metabolism, transmembrane calcium influx, and platelet thromboxane synthesis. Further documented effects include the blockade of ATP-sensitive inward rectifier potassium channel 8 (KIR6.1), and stimulation of endothelial cell prostacyclin production.[2]

Proadifen exerts apoptotic/anti-proliferate (tumour suppressing) effects in certain forms of cancer (HT-29 colon adenocarcinoma), believed to be caused by mediation of glycogen synthase kinase 3 β (GSK-3β). In the same study administration of proadifen was demonstrated to produce time- and dose-dependent phosphatidylserine externalization, caspase-3 activation and PARP cleavage. Intense upregulation of NAG-1 and ATF3 and downregulation of Mcl-1 and Egr-1 were also observed.[3]

Proadifen has been demonstrated to normally inhibit the nicotinic acetylcholine receptor (NAChR) and muscarinic acetylcholine receptor (MAChR) in rats.[2]


  1. ^ Marshall, FN; Williamson, HE (1964). "Natruretic Response During Infusion of Beta-Diethylaminoethyl-Diphenylpropyl Acetate Hydrocloride (Skf 525-A)". The Journal of Pharmacology and Experimental Therapeutics. 143: 395–400. PMID 14161153.
  2. ^ a b "Proadifen hydrochloride (CAS 62-68-0)". Santa Cruz Biotech.
  3. ^ Jendželovský R, Koval J, Mikeš J, Papčová Z, Plšíková J, Fedoročko P (September 2012). "Inhibition of GSK-3β reverses the pro-apoptotic effect of proadifen (SKF-525A) in HT-29 colon adenocarcinoma cells". Toxicol In Vitro. 26 (6): 775–82. doi:10.1016/j.tiv.2012.05.014. PMID 22683934.