Studies on some biologically active dextrans.

The relationship between the structures of six native dextrans and their effects on nonspecific resistance to infection (n.s.r.i.) in mice and also anticomplementary activity has been studied. The data obtained showed that the n.s.r.i. activity of dextrans generally increased with increase of extent of branching, but no direct correlation between these two factors was found. Data on exodextranase-catalyzed hydrolysis of dextrans suggest that the length of the outer chains may be important for the n.s.r.i. activity of the dextrans. Dextrans characterized by a significant extent of branching were anticomplementary, but no relationship between extent of branching and anticomplementary activity was observed.