Biological Activity of a Derivative of the Gitrovorum Factor.

Abstract
Exposure of citrovorum factor (leucovorin) solns. to pH 2 for 24 hrs. at 25[degree]C resulted in inactivation of Leuconostoc citrovorum activity, but produced no alteration in the activity of Streptococcus faecalis. Acid-treated leucovorin was about 10% as active as leucovorin in reversing Aminopterin toxicity in mice, and also less active in patients with pernicious anemia in relapse.