The structure and hydrogen bond of tert-butoxycarbonyl-D,L-isoleucyl-glycyl methyl ester

The crystal structure of tert-butoxycarbonyl-D, L-isoleucyl-glycyl methyl ester was determined by the X-ray method. The space group is P2₁ with a = 9.115(3), b= 12.075(4), c = 16.258(5) Å, β = 89.84(3) and Z = 4. It was observed that in the peptides which contain IleGly fragment the carbonyl group of Gly residue has less tendency to form hydrogen bond than that of Ile residue. This tendency was supported by the atomic net charges calculated with the quantum mechanics program CNDO/2.