Study On Screening Of Lactonizing Lipase And Synthesize Of Cyclopentadecanolide

Cyclopentadecanolide is one of the macrocycle musk, which could be used in many fields broadly, such as perfume, cosmetic, food, medical and etc.. At present, Cyclopentadecanol ide could be prepared with chemical synthesis only. In this paper, Cyclopentadecanolide was prepared using 15-hydroxypentadecanoic acid as material and microbe lipases as catalyst. The researches included: Screening of strains producing lipase used to prepare Cyclopentadecanolide; Optimization of lipase preparation conditions; Purification of lipases; Study of effects on close-cycle reaction of 15-hydroxypentadecanoic acid.Fifteen strains producing lipase were obtained and six strains out of the fifteen strains have the lactonizat ion abilities. The lipase preparation conditions of Candida sp. GXU01and Candida sp. GXU03 were studied in detail. The results showed that the lipase activities of Candida sp. GXU01 and Candida sp. GXU03 reached 20. 69u/ml and 16. 89u/ml respectively. For the two lipases.the lipase activities were maximal at 40 C and pH 7.0. For Candida sp. GXU01, the loss of lipase activity was 20% at 50 C for 15 mins and for Candida sp. GXU03, the loss of lipase activity was 30% at 50 C for 15 min. The activity of Candida sp. GXU01 lipase was distributed over 40%~50% saturation of ammonium sulfate, and the ability of Candida sp. GXU03 lipase was distributed over 40%~60%.The Candida sp. GXU01 lipase was purified with gel filtration chromatography on Sephacryl S-400 column and showed two kinds of I ipases . Both lipases were likely to have the catalysis abi I ity for the synthesis of cyclopentadecanolide.The synthesis of Cyclopentadecanolide was studied. The results indicated that the optimal pH for the lipase to synthesize Cyclopentadecanolide was 6.0 and the catalysis ability of lipase in the cyclohexane is superior to that in the benzene. The catalysis abilities of lipases for the synthesis of cyclopentadecanolide in different solvent were also studied. The lipase from Candida sp. had higher catalysis ability in the cyclohexane than in the benzene. On the contrary, for the lipase fromPeniciIlium sp. , the catalysis ability in the benzene is about 3.4 times higher than in the cyclohexane. The conversion of 15-hydroxypentadecanoic acid reached 88% with the catalysis of Iipase of Candida sp. GXU01.