碱异构化亚麻酸合成共轭亚麻酸

Synthesis of Conjugated Linolenic Acids by Alkali Isomerization of Linolenic Acids

采用碱异构化法从α-亚麻酸(LN)合成共轭亚麻酸(CLN),用紫外和红外光谱表征产物,并用气相色谱分析产物中CLN的百分含量。用紫外吸光度监控,考察了催化剂种类和用量、溶剂种类和用量、异构化反应时间及温度对CLN含量的影响。实验结果表明,当m(LN)∶m(KOH)∶V(EG)=1∶1.6∶10时在160℃下异构化反应100 min,CLN含量最高可达40.0%。CLN粗产品经尿素包合后CLN含量可达74.3%,而经低温分步结晶处理CLN含量可达90%以上。

Conjugated linolenic acids(CLN) are synthesized by alkali isomerization of α-linolenic acid(LN), and the structure of CLN is identified by ultraviolet and infrared spectroscopy, the yield of CLN is determined by gas chromatography. Monitored by ultraviolet absorbance, effects of catalyst types and dosages, solvent types and dosages, isomerization times and temperatures on the CLN levels are investigated. Experimental results show that the highest content of CLN of 40.0% in crude products is obtained under appropriate conditions of m(LN)∶m(KOH)∶V(EG) = 1∶1.6∶10 at 160℃ for 100 min. A 74.3% content of CLN is enriched through urea inclusion of the crude CLN product, while more than 90% by low-temperature stepwise crystallization.