Studies on a new immunoactive peptide, FK-156. III. Structure elucidation.

Abstract
FK-156, C20H33N5O11, mp [melting point] 143-148.degree. C, is a new immunostimulant produced by Streptomyces olivaceogriseus and S. violaceus. The structure was elucidated to be D-Lac-L-Ala-.gamma.-D-Glu-(L)meso-.alpha.,.epsilon.-A2pm(L)-GlyOH on the basis of chemical and spectroscopic properties.