Ac2-DPD, the bis-(O)-acetylated derivative of 4,5-dihydroxy-2,3-pentanedione (DPD) is a convenient stable precursor of bacterial quorum sensing autoinducer AI-2

Ac2-DPD, the bis-(O)-acetylated derivative of 4,5-dihydroxy-2,3-pentanedione (DPD), was prepared both as a racemic mixture and in the optically active form found in naturally occurring DPD. It was shown to exhibit the same ability as DPD to induce bioluminescence in Vibrio Harveyi and β-galactosidase activity in Salmonella enterica Typhimurium, both Gram-negative bacteria. Likewise, it was also shown to inhibit biofilm formation in Gram-positive Bacillus cereus. The most likely hypothesis is that Ac2-DPD activity is due to the release of DPD by in situ hydrolysis of the ester groups. Importantly, by contrast with DPD, Ac2-DPD proved to be a stable compound which can be purified and stored.