1. Peptidehelicenes in solution and gel: chiral discrimination through interactions between two types of helixes
- Author
-
Yuichi Masuoka, Koh-ichi Yamada, Katsuhito Sugahara, Masami Kawase, Kumiko Ohtsuka, Hiroko Nakagawa, and Chika Kobayashi
- Subjects
chemistry.chemical_classification ,Stereochemistry ,Organic Chemistry ,Phenylalanine ,Peptide ,Catalysis ,Inorganic Chemistry ,chemistry ,Moiety ,Molecule ,Physical and Theoretical Chemistry ,Enantiomer ,Elongation ,Enantiomeric excess - Abstract
Helical [5]thiaheterohelicene 5HM, which rapidly interconverts between P and M enantiomers in solution, was connected to helical l -phenylalanine oligomers with an ester linkage to give peptidehelicenes (5Fn, where n: number of bonded phenylalanines). The characteristics of 5F4 and 5F5 with two types of helixes in a molecule were investigated, particularly in comparison with those of 5F1–5F3 with an incomplete coil of a peptide moiety. l -Phenylalanine peptide chains induced a shift in the equilibrium between the P and M helixes of 5HM toward the P side for all the 5Fns examined. The enantiomeric excess (ee) of the P form increased with a decrease in temperature, together with an elongation of the peptide chains. 5F4 and 5F5 in hot solutions of some solvents formed a gel at room temperature, whereas 5F1–5F3 showed no such behavior. In this gel, the stable helical form of the 5HM moiety in 5F4 and 5F5 was observed to be the M form in contrast to that in their solutions.
- Published
- 2010
- Full Text
- View/download PDF