Reaction Mechanism of Enzymatic Degradation of Poly(butylene succinate-co-terephthalate) (PBST) with a Lipase Originated from Pseudomonas cepacia

✍ Scribed by Nozomi Honda; Ikuo Taniguchi; Matsatoshi Miyamoto; Yoshiharu Kimura

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 172 KB
• Volume: 3
• Category: Article
• ISSN: 1616-5187
• DOI: 10.1002/mabi.200390023

✦ Synopsis

Abstract

An aliphatic/aromatic copolyester, poly(butylene succinate‐co‐terephthalate) (PBST), was prepared to investigate the effect of the aromatic units on the enzymatic degradation of the poly(butylene succinate) (PBS) derivatives in the presence of a lipase originated from Pseudomonas cepacia (Lipase PS®). The degradability of PBST was found to increase with increasing BS content. The degradation products were analyzed in detail by liquid chromatograph mass spectrometry (LC‐MS). A hexamer containing one terephthalate unit was the largest fragment among the diverse fragments detected, while a pentamer was the largest one consisting only of succinate units. The oligomeric fragments cut out from the polymer chain were involved in the secondary hydrolysis into 4‐hydroxybutyl succinate (BS~H~) and terephthalate (BT~H~). The trimeric fragments tetramethyl disuccinate (SBS~H~) and succinate terephthalate (SBT~H~), having both carboxyl end groups, were slowly hydrolyzed by a nonspecific mechanism. Based on these data, the overall mechanism of the enzymatic hydrolysis of this aliphatic/aromatic copolyester is proposed, in which PBST undergoes endo hydrolysis.

A plausible mechanism of enzymatic hydrolysis of PBST with Lipase PS®.

magnified imageA plausible mechanism of enzymatic hydrolysis of PBST with Lipase PS®.