4,4,14α-trimethyl 9β,19-cyclo-5α-26-homocholesta-24,26-dien-3β-ol: a potent mechanism-based inactivator of Δ24(25)- to Δ25(27)-sterol methyl transferase

The title compound (4A) was synthesized and tested as a mechanism-based inactivator of the sterol methyl transferase (SMT) enzyme from Prototheca wickerhamii. Using cycloartenol as substrate, 4A was found to exhibit time-dependent inactivation kinetics, generating a Ki value of 30 μM and Kinact value of 0.30 min−1.