School of Food Science and Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510640, China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510641, China.
J Agric Food Chem. 2021 Nov 10;69(44):13102-13112. doi: 10.1021/acs.jafc.1c03092. Epub 2021 Oct 27.
In this paper, an enzymatic route for synthesizing phenolic glycoside azelaic acid esters was successfully set up via lipase-catalyzed esterification and transesterification. Among the lipases tested, lipase B (Novozyme 435) showed the highest activity in catalyzing esterification and (Lipozyme TLIM) gave the highest substrate conversion in catalyzing transesterification for the synthesis of ester. The addition of 4A molecular sieves into the reaction system is found to be an effective method for absorption of the byproduct water and methanol, with which the substrate conversions of the enzymatic esterification and transesterification were 98.7 and 95.1%, respectively. Also, the main product ratios in transesterification were above 99.0% with lipozyme TLIM as a catalyst because the hydrolysis reaction was hindered. The results of the physical and biological properties indicate that all esters had higher Clog values than their parent compounds. Also, the esters showed higher intracellular tyrosinase inhibitory and depigmentating activities than phenolic glycosides, azelaic acid (AA), and their physical mixtures due to their higher membrane penetration and tyrosinase inhibitory effects. In particular, piceid 6″--azelaic acid ester (PIA) showed the strongest inhibitory effect against melanin production. Its inhibitory rate was 77.4% at a concentration of 0.25 mM, about 4.2 times higher than that of arbutin (18.5%).
本文通过脂肪酶催化酯化和酯交换反应，成功建立了合成酚糖苷壬二酸酯的酶法途径。在所测试的脂肪酶中，脂肪酶 B（诺维信 435）在催化酯化反应中表现出最高的活性，而脂肪酶 TLIM 在催化酯交换反应中给出了最高的底物转化率，用于合成酯。发现向反应体系中加入 4A 分子筛是一种有效吸收副产物水和甲醇的方法，通过这种方法，酶促酯化和酯交换的底物转化率分别达到 98.7%和 95.1%。此外，由于水解反应受到阻碍，当使用脂肪酶 TLIM 作为催化剂时，酯交换反应中的主要产物比例均高于 99.0%。物理和生物学性质的结果表明，所有酯的 ClogP 值均高于其母体化合物。此外，由于它们具有更高的膜穿透性和酪氨酸酶抑制作用，酯类表现出比酚糖苷、壬二酸（AA）及其物理混合物更高的细胞内酪氨酸酶抑制和脱色活性。特别是白皮杉醇 6′-壬二酸酯（PIA）对黑色素生成的抑制作用最强。在 0.25mM 的浓度下，其抑制率为 77.4%，约比熊果苷（18.5%）高 4.2 倍。
