Inhibitor of DNA-dependent protein kinase (DNA-PK) (IC50 = 15 μM), an enzyme involved in the non-homologous end-joining (NHEJ) pathway of double-stranded DNA break (DSB) repair in human cells. Displays 100-fold higher potency than its analog vanillin and does not affect PKC activity. Produces lethal effects on cisplatin-treated D5037 cells upon continuous exposure.