T. Ishizu et S. Noguchi, ENANTIOMER-DIFFERENTIATING ABILITY OF CYCLO(L-PHE-L-PRO)(4) HAVING A RIGID SKELETON FOR PHENYLALANINE METHYLESTER HYDROCHLORIDE, Chemical and Pharmaceutical Bulletin, 45(7), 1997, pp. 1202-1204
The formation constant of the 1:1 complex of cyclo(L-Phe-L-Pro)(4) (1)
with L-PheOMe . HCl was about 13.2 times that of the complex with D-P
heOMe . HCl. The 1:1 comples of 1 with L-PheOMe . HCl formed three int
ermolecular hydrogen bonds between Pro(2)CO, Phe(1)CO and the amino gr
oup, and Phe(2)NH and the carbonyl group, whereas that with D-PheOMe .
HCl formed only one between Phe(1) CO and the amino group.