摘要
采用固定化脂肪酶Candida sp.99-125在无溶剂体系中催化合成油酸低碳醇酯,考察了加酶量、温度、酸醇摩尔比和醇结构对油酸酯化率的影响。结果表明,加酶量为底物质量的3%,最适温度为20℃,酸与醇摩尔比为1∶1,甲醇对该酶有一定的毒性,由于空间位阻效应,该酶对伯醇具有高选择性,对仲醇、叔醇的选择性低,且对长链脂肪酸催化活性高,对带支链的多元酸、多元醇活性低。该酶重复使用5次,酶活性基本没有降低。与传统的化学法相比,用该酶催化合成酯类化合物的色泽更浅。
The esterification between oleic acid and alkyl alcohols in solvent-free systems were catalyzed by an immobilized lipase from Candida sp. 99-125. The effects of several factors including enzyme concentration, temperature, molar ratio of oleic acid to alkyl alcohols, and structure of alcohols have been also investigated. The results indicated that the reactions catalyzed by lipase at 20℃ with the presence of 3% （ mass fraction） lipase, a 1 ： 1 molar ratio of oleic acid to alcohols, afforded products in high yields. Methanol has certain toxicity on the activity of the lipase. The enzyme showed high selectivity to primary alcohols and low selectivity to secondary and tertiary alcohols because of the sterical effect. It showed high activity to long chain fatty acids and low activity to polybasic acids and polyhydric alcohols with branched chain. The lipase showed no appreciable loss in activity after being continuously operated for 5 times. The enzymatic synthesis gave purer products, co
出处
《应用化学》
CAS
CSCD
北大核心
2013年第9期1030-1035,共6页
Chinese Journal of Applied Chemistry
基金
国家重点基础研究发展计划资助项目(973计划
2012CB725204和2011CB710803)
长江学者和创新团队发展计划资助项目(IRT1066)
关键词
生物催化
固定化脂肪酶
酯化
油酸低碳醇酯
无溶剂体系
mpared with the conventional chemical system. enzymatic catalysis, immobilized lipase, esterification, oleates, solvent-free system
