Ancorinosides B±D were isolated from the marine sponge Penares sollasi Thiele as inhibitors of membrane type 1 matrix metalloproteinase (MT1-MMP). Their structures were elucidated to be tetramic acid glycosides related to ancorinoside A by spectroscopic and chemical methods. Ancorinosides B±D inhibited MT1-MMP with IC50 values of 180±500 mg/mL.