Disclosed herein is the use of a compound of formula I (an alpha-hydroxy carbonyl compound) as an activating agent for the conversion of a reduction-activated prodrug, such as metronidazole, Chloramphenicol, nitrofurazone, mitomycin C, mitosene, cyclopropamitosene, 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide； to a corresponding active substance, wherein the substituents are as defined within the specification, and wherein the reduction i) is effected at a pH of between 7 and 11； or ii) is conducted in the presence of a base that is an amine, a nitrogen-based heterocycle or a carbonate or bicarbonate salt； furthermore the compound of formula I is capable of forming a cyclic dimer of formula Ia.
