本文研究了非水相条件下利用固定化脂肪酶IMTL催化柚皮苷的酯交换反应，得到了一系列带有不同链长脂肪酸的柚皮苷酯。固定化脂肪酶IMTL对反应显示出高催化活性，其底物转化率均达到90%以上。在4 mL叔戊醇体系中，50 mg IMTL酶，柚皮苷:酰基供体=1:20，50 ℃的条件下，反应3 h后，区域选择性达99%以上。在对柚皮苷酯进行液相分析、质谱和核磁鉴定后，发现酰化产物为柚皮苷-6’’-O-酯。研究发现柚皮苷酯的ClogP发现随着链长的增长而增加，其中柚皮苷肉豆蔻酯的ClogP值为6.50。HepG2细胞抑制实验的结果显示柚皮苷酯对HepG2细胞增殖的抑制活性与柚皮苷酯的脂溶性相关。相较于柚皮苷，柚皮苷酯对HepG2细胞具有更好的抑制增殖作用。带有长链脂肪酸的柚皮苷肉豆蔻酯具有更加良好的脂溶性，对HepG2细胞增殖抑制作用更强（2.28%）。以上研究表明酶促合成生成的柚皮苷酯比柚皮苷具有更广阔的应用前景。

In this paper, the immobilized lipase IMTL was used to catalyze the transesterification of naringin under non-aqueous conditions to produce a series of naringin esters with different fatty acid chain length. The immobilized lipase IMTL enzyme showed high catalytic activity towards the reaction, with substrate conversion ratios being above 90%. In a 4 mL tert-amyl alcohol system, 50 mg of lipase IMTL, naringin: acyl donor=1:20, and the reaction was performed at 50 ℃ for 3 hours, and the regioselectivity was above 99%. After the naringin esters were analyzed and identified by HPLC, mass spectrometry, and nuclear magnetic resonance, the acylated products were naringin-6’’-o-ester. It was found that the ClogP values of naringin esters increased with the increase of the chain length. Among them naringin myristate ClogP value was 6.50. The results of HepG2 cell inhibition experiments showed that the inhibitory activity of naringin esters on HepG2 cell proliferation was closely related to their lipophilicities. Compared with naringin, naringin esters had a better inhibitory effect on HepG2 cell. Naringin myristate with long-chain fatty acid had better fat solubility and stronger inhibitory effect on HepG2 cell proliferation (2.28%). The enzymatically synthesized esters may have a broader application prospect than naringin.

国家自然科学基金资助项目(21676105；21978101)；广州市科技计划民生科技项目(201803020031)