Synthesis of poly(L-lactide) end-capped with lactose residue.
The synthesis of poly(L-lactide) (polyLA) end-capped with lactose residue was studied from the standpoint of development of a new bioabsorbable material. After the hydroxyl group of t-butoxycarbonyl(Boc)-aminoethanol was converted to Boc-aminoethanol-OK by using potassium/naphthalene, L-lactide was polymerized in tetrahydrofuran using Boc-aminoethanol-OK as an initiator at room temperature to prepare polyLA-NHBoc. Subsequently, the removal of the Boc group in terminal Boc-aminoethanol residue was performed by treatment of formic acid to obtain the amino group end-capped polyLA (polyLA-NH(2)) as a reactive polyLA derivative. The coupling reactions of lactose with polyLA-NH(2) were investigated by two methods; the synthetic method through reductive amination of lactose with polyLA-NH(2) in the presence of sodium cyanoborohydride as a reducing agent did not give high degree of substitution of end-capped lactose residue per polyLA molecule, whereas the synthetic method through the ester interchange reaction of lactonolactone with polyLA-NH(2) gave Lac-polyLA perfectly end-capped with lactose residue.
Faculty of Engineering & High Technology Research Center, Kansai University, Suita, Osaka 564-8680, Japan. touchi@ipcku.kansai-u.ac.jp
Tatsuro
T
Ouchi
Tomoyuki
T
Uchida
Hidetoshi
H
Arimura
Yuichi
Y
Ohya
D000586:Amination; D007785:Lactose / Q000138:chemical synthesis* / Q000737:chemistry; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry
D011091:Polyesters; C033616:poly(lactide); D007785:Lactose