The direct three-component aza-Diels–Alder reaction was conducted with lipase as a catalyst for the first time. Under the optimized conditions, the aza-Diels–Alder reaction catalyzed by lipase from Candida sp. 99–125 provided the products in moderate to excellent yields. Meanwhile, the endo / exo ratio reached up to 88:12.
In order to study the effect of metal ions on the enzymatic hydrolysis of hemp seed oil by Candida sp. 99–125, the spectroscopy, stability and hydrolytic activity of the biocatalyst were investigated in presence of Ca 2+ , Mg 2+ , Fe 2+ , Fe 3+ , Cu 2+ , Sn 2+ , Pb 2+ , Zn 2+ and Ba 2+ metal ions, respectively. The UV spectroscopy showed that all the metal ions enhanced the absorbance but the decrease of fluorescence intensity was observed. All the metal ions could improve the lipase thermal stability except Cu 2+ and Ba 2+ . Hydrolysis of hemp seed oil proved that Ca 2+ , Fe 3+ , Pb 2+ and Ba 2+ could significantly improve the hydrolytic rate, and metal ions could influence lipase selectivity. The study revealed that metal ions could improve lipase stability, hydrolysis activity in the hydrolytic process of hemp seed oil by Candida sp. 99–125.
Pei Wang,Zhaodi Ke,Juanjuan Yi,Xin Liu,Limin Hao,Qiaozhen Kang,Jike Lu
To enhance the stability of lipases, the additive method is attractive because of its high efficiency and simplicity, of which β-cyclodextrin (β-CD), as an additive has attracted attention. In the present study, the effects of β-CD on enzymatic hydrolysis of hemp seed oil by lipases were investigated. The stability, spectroscopy, and reusability of C andida sp.99–125 were compared by the addition of β-CD, respectively. The results showed that Candida sp.99–125 could produce the highest yield of α-linolenic acid (ALA, 18.27%, w/w) in the presence of β-CD after 24h, and the thermal stability of lipase was also improved. The UV spectroscopy showed that the absorbance of lipase decreased with increasing concentrations of β-CD and the fluorescence result was similar. Moreover, the reusability of lipase with β-CD was better than free lipase. This study revealed that β-CD could increase hydrolysis activity and stability of the lipase, thereby improving the hydrolytic process of hemp seed oil by Candida sp.99–125.
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