 On the hydroxypyrone ring, three positions are available to attach backbones, position 2-, 5- and 6-.Hydroxypyrone-based MMP inhibitors are structurally corresponding to the pyrimidinetriones.A recent inhibitor is the compound 3-hydroxypyran-4-one nominated 868368-30-3.It is MMP-3 selective and its 0,0-bidentate chelation of zinc is the structural part proposed to be responsible for the MMP recognition.