Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin 300072, PR China.
Int J Biol Macromol. 2019 May 1;128:132-139. doi: 10.1016/j.ijbiomac.2019.01.104. Epub 2019 Jan 23.
5-Formyl-2-furancarboxylic acid (FFCA) is increasingly important building blocks, which has promising applications in fuels, chemical intermediates, drugs, etc. However, highly selective oxidation of 5-hydroxymethylfurfural (5-HMF) to FFCA by enzyme catalysis is a new challenging problem due to the absence of specific enzymes. Recently we identified a kind of laccase (CotA-TJ102) from Bacillus subtilis TJ-102 could convert selectively 5-HMF to FFCA, and no further oxidation production (such as FDCA). The initial conditions resulted in low 5-HMF conversion ratio at 23.5% and low FFCA yield at 19.3% after 96 h, but high FFCA selectivity at 82.4%. Then the proposed mechanism in detail for the selective oxidation of HMF to FFCA by CotA-TJ102 was deduced and discussed. After optimization of reaction parameters such as pH, TEMPO concentration and temperature, FFCA could be obtained in a high yield of 98.55% with a 5-HMF conversion ratio of nearly 100% after a short reaction time of 12 h. Finally, after immobilization of CotA-TJ102 on magnetic nanoparticles, the FFCA yield remained 83.28% for 10 of recycling times based on the high FFCA selectivity (>96%), which reflected high stability and good reusability. Therefore, this enzymatic approach constitutes a promising method for the green production of FFCA.
5-甲酰基-2-糠酸（FFCA）是一种越来越重要的结构单元，在燃料、化学中间体、药物等方面具有广阔的应用前景。然而，由于缺乏特异性酶，通过酶催化选择性氧化 5-羟甲基糠醛（5-HMF）生成 FFCA 是一个新的具有挑战性的问题。最近，我们从枯草芽孢杆菌 TJ-102 中鉴定出一种漆酶（CotA-TJ102），它可以选择性地将 5-HMF 转化为 FFCA，且没有进一步氧化产物（如 FDCA）。初始条件下，96 小时后 5-HMF 的转化率仅为 23.5%，FFCA 的产率为 19.3%，但 FFCA 的选择性高达 82.4%。然后详细推导并讨论了 CotA-TJ102 选择性氧化 HMF 生成 FFCA 的可能机制。在优化反应参数（如 pH 值、TEMPO 浓度和温度）后，FFCA 的产率可高达 98.55%，5-HMF 的转化率接近 100%，反应时间仅为 12 小时。最后，通过将 CotA-TJ102 固定在磁性纳米粒子上，在高 FFCA 选择性（>96%）的基础上，FFCA 的产率在 10 次循环后仍保持 83.28%，这反映了其具有较高的稳定性和良好的可重复使用性。因此，这种酶法为 FFCA 的绿色生产提供了一种很有前景的方法。
