Cyclo(-l-prolyl-l-valinyl-) from Burkholderia thailandensis MSMB43

The title compound [systematic name: (3S,8aS)-3- isopropylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione], C₁₀H ₁6N₂O₂, is a newly isolated cyclic dipeptide from Burkholderia thailandensis MSMB43. There are two independent molecules in the asymmetric unit. Two C atoms and their attached H atoms in the five-membered ring of one of the molecules are disordered over two sets of sites in a 0.715(5):0.285(5) ratio. The two independent molecules have the same configuration and the absolute configurations of the chiral centers were determined based on the observation of anomalous dispersion. In the crystal, two types of N-H⋯O hydrogen bonds link pairs of independent molecules.