Type II glyoxalase, isozyme of GloB, that hydrolyzes (R)-S-lactoylglutathione to (R)-lactate and glutathione. Plays a role in methylglyoxal (MG) detoxification. an S-(2-hydroxyacyl)glutathione + H2O = a 2-hydroxy carboxylate + glutathione + H(+) (R)-S-lactoylglutathione + H2O = (R)-lactate + glutathione + H(+) Binds 2 Zn(2+) ions per subunit. Secondary metabolite metabolism; methylglyoxal degradation; (R)-lactate from methylglyoxal: step 2/2. Belongs to the metallo-beta-lactamase superfamily. Glyoxalase II family.