Inhibition of vertebrate squalene epoxidase by isoprenyl gallates and phenylalkyl gallates

Galloy esters with ‘substrate-like’ isoprenoid or phenylalkyl side chains were newly synthesized and tested for the enzyme inhibition activities toward recombinant rat squalene epoxidase. Isoprenyl gallates (4–6) showed good inhibition (IC50=1.5–5.1 μM), as potent as previously reported substrate analogues, while phenylalkyl gallates (7–10) were moderate inhibitors of the enzyme (IC50=12–61 μM).