Thermal Synthesis of Polypeptides from N-Butyloxycarbonyl Oligopeptides Containing Aspartyl Residue at C-Terminus

Figure 8

Gel permeation chromatograms of the reaction mixtures of Boc-Gly-L-Asp (5a) at varying temperatures and times: (a) 110°C, 24 h; (b) 120°C, 24 h; (c) 150°C, 2 h; and (d) 170°C, 2 h. Solid phase: Sephadex G-25F. Eluate: 0.5 M acetic acid. Volume per a test tube: 3 mL. fa: ninhydrin-negative, higher molecular weight fractions; fb: ninhydrin-positive lower molecular weight fractions.

(a)

(b)

(c)

(d)