Enzymatic Hydrolysis of Poly (L-lactide-co-ε-caprolactone) s
Enzymatic Hydrolysis of Poly (L-lactide-co-ε-caprolactone) s
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聚（L-丙交酯-共-ε-己内酯）的酶水解
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
I. Arvanitoyannis
中科院分区：
文献类型：
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作者：
A. Nakayama;N. Kawasaki;N. Yamamoto;I. Arvanitoyannis
采用酶法和非酶法研究了L-丙交酯-己内酯共聚物的生物降解性。水解在磷酸盐缓冲液（pH 7.0）中在37°C下进行24小时，并且使用的酶是来自少根根霉、德氏根霉和Candida cvlindracea的脂肪酶。这些聚合物的可水解性通过测量TOC值（总有机碳浓度）来评价，TOC值显示水解的水溶性产物的量。以辛酸锡为引发剂，通过开环聚合合成了共聚物。虽然聚（L-丙交酯），聚（ε-己内酯）和它们的无规共聚物与上述三种脂肪酶水解，少根根霉和根霉delemar脂肪酶被证明是最有效的。酶水解的程度受到共聚物组成的影响。共聚物，其中表现出最高的敏感性水解，是一个含有82摩尔%的ε-己内酯单元。聚合物也被非酶水解（70°C，1周），并且结果与酶水解的结果类似，清楚地表明共聚物组成对TOC结果的影响。然而，TOC测量显示富含L-丙交酯的共聚物，特别是具有80摩尔%丙交酯含量的共聚物，更容易水解。这些结果表明，聚（ε-己内酯）可以很容易地与脂肪酶降解，而聚（L-丙交酯）也可以与简单的水解降解。富含e-己内酯的低聚物、6-羟基己酸和乳酸用NMR鉴定为水解的主要产物。
Biodegradability of poly (L-lactide-co-e-caprolactone) s was evaluated with both enzymatic and non-enzymatic hydrolysis. The hydrolysis was carried out in phosphate buffer (pH 7.0) at 37°C for 24h and the enzymes used were lipases from Rhizopus arrhizus, Rhizopus delemar, and Candida cvlindracea. The hydrolyzability of these polymers was evaluated with measurement of TOC values (total organic carbon concentration) which show the amount of the hydrolyzed water-soluble products. The copolymers were synthesized by ring-opening polymerization using tin (II) octanoate as initiator. Although poly (L-lactide), poly (e-caprolactone) and their random copolymers were hydrolyzed with all three above mentioned lipases, Rhizopus arrhizus and Rhizopus delemar lipases proved to be the most effective. The extent of enzymatic hydrolysis was considerably affected by copolymer composition. The copolymer, which showed the highest susceptibility to hydrolysis, was the one containing 82 mol% e-caprolactone unit. The polymers were also non-enzymatically hydrolysed (70°C, 1 week) and the results were similar to those of enzymatic hydrolysis showing clearly the influence of copolymer composition on the TOC results. However, TOC measurements showed that the L-lactide rich copolymers, and in particular the one with 80 mol% lactide content, were more susceptible to hydrolysis. These results suggest that poly (e-caprolactone) can be easily degraded with lipase, whereas poly (L-lactide) can be also degraded with simple hydrolysis. e-Caprolactone rich oligomers, 6-hydroxycaproic acid, and lactic acid were identified with NMR as the main products of hydrolysis.