Abstract
The protected peptide fragment 24-45 of human proinsulin, Bpoc-Phe-Phe-Tyr(But)-Thr-(But)-Pro-Lys(Boc)-Thr(But)-Arg(H2SO4)-Arg-(H2SO4)-Gl u(OBut)-Ala-Glu(OBut)-Asp(OBut)-Leu-Gln-Val-Gly-Gin-Val-Glu(OBut)-Leu-Gly-Oh, was synthesized from the two intermediate fragments 24--33 and 34--45, and purified by countercurrent distribution in the carbon tetrachloride system (K = 2.5).