Yakai Feng, D. Klee, H. Keul
Dec 1, 2000
Citations
0
Influential Citations
47
Citations
Journal
Macromolecular Chemistry and Physics
Abstract
The enzymatic ring-opening polymerization of 6-membered cyclic depsipeptides, 3(S)-isopropyl-morpholine-2,5-dione, 3(R)-isopropyl-morpholine-2,5-dione, 3(R,S)-isopropyl-morpholine-2,5-dione, (3S, 6R, S)-3-isopropyl-6-methyl-morpholine-2,5-dione, 3(S)-isobutyl-morpholine-2,5-dione, 3(S)-sec-butyl-morpholine-2,5-dione, 6(S)-methyl-morpholine-2,5-dione, and 6(R,S)-methyl-morpholine-2,5-dione in the bulk, was investigated by using the lipase PPL as a catalyst. In the absence of the enzyme, the monomers were recovered, indicating that the present polymerization proceeds through enzymatic catalysis. During the polymerization of morpholine-2,5-diones racemization of both the amino acid and the S-lactic acid moiety takes place. Enzymatic polymerization produces polydepsipeptides with a carboxylic acid group at one end and a hydroxyl group at the other one.