Synthesis and CYP24A1 inhibitory activity of (E)-2-(2-substituted benzylidene)- and 2-(2-substituted benzyl)-6-methoxy-tetralones

A series of (E)-2-(2-substituted benzylidene)- and 2-(2-substituted benzyl)-6-methoxy-tetralones were prepared, using an efficient synthetic scheme, and evaluated for their inhibitory activity against cytochrome P450C24A1 (CYP24A1) hydroxylase. In general the reduced benzyl tetralones were more active than the parent benzylidene tetralones. The 2-ethyl and 2-trifluoromethyl benzyl tetralone derivatives (4c and 4b) showed optimal activity in this series with IC50 values of 1.92 μM and 2.08 μM, respectively compared with the standard ketoconazole IC50 0.52 μM. The 2-bromobenzyl tetralone (4d) showed a preference for CYP27A1 (IC50 59 nM) over CYP24A1 (IC50 16.3 μM) and may be a useful lead in CYP27A1 inhibition studies. The 2-ethylphenyl benzyl derivative (9c), which showed weak activity against the wild type CYP24A1 (IC50 25.57 μM), exhibited enhanced inhibitory activity towards L148F and M416T mutants, this difference in activity for the L148F mutant has been explained using molecular modelling.

A series of (E)-2-(2-substituted benzylidene)- and 2-(2-substituted benzyl)-6-methoxy-tetralones were prepared and evaluated for their inhibitory activity against cytochrome CYP24A1, CYP27A1 and CYP24A1 mutant strains.Figure optionsDownload as PowerPoint slide