Key Laboratory of Characteristics Garden Plants Resource in Fujian and Taiwan, School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou, 363000, PR China.
Chinese Academy of Inspection and Quarantine, PR China.
Int J Biol Macromol. 2021 Mar 31;174:485-493. doi: 10.1016/j.ijbiomac.2021.01.190. Epub 2021 Feb 3.
Three phenolic acids including p-hydroxybenzoic acid (PHBA), 3,4-dihydroxybenzoic acid, (DHBA), and gallic acid (GA) were grafted onto native pectin (Na-Pe) through enzymatic method. Ultraviolet-visible spectrometry, Fourier transform infrared spectroscopy, and H NMR analyses were used to explore the reaction mechanism. Results indicated that the p-hydroxyl of the phenolic acids reacted with the methoxycarbonyl of pectin through transesterification, and a covalent connection was formed. The phenolic acid contents of PHBA modified pectin (Ph-Pe), DHBA modified pectin (Dh-Pe), and GA modified pectin (Ga-Pe) were 20.18%, 18.87%, and 20.32%, respectively. After acylation with phenolic acids, the 1,1-diphenyl-2-picryl hydrazine clearance of pectin changed from 7.68% (Na-Pe) to 6.88% (Ph-Pe), 40.80% (Dh-Pe), and 90.30% (Ga-Pe), whereas its inhibition ratio of pectin increased from 3.11% (Na-Pe) to 35.02% (Ph-Pe), 66.36% (Dh-Pe), and 77.89% (Ga-Pe). Moreover, compared with Na-Pe, modified pectins exhibited better emulsification properties and stronger antibacterial activities against both Escherichia coli and Staphylococcus aureus.
三种酚酸，包括对羟基苯甲酸（PHBA）、3,4-二羟基苯甲酸（DHBA）和没食子酸（GA），通过酶法接枝到天然果胶（Na-Pe）上。利用紫外可见光谱、傅里叶变换红外光谱和 H NMR 分析探讨了反应机理。结果表明，酚酸的酚羟基与果胶的甲氧基羰基通过酯交换反应，形成了共价键连接。PHBA 改性果胶（Ph-Pe）、DHBA 改性果胶（Dh-Pe）和 GA 改性果胶（Ga-Pe）中的酚酸含量分别为 20.18%、18.87%和 20.32%。经酚酸酰化后，果胶的 1,1-二苯基-2-苦基肼清除率从 7.68%（Na-Pe）降至 6.88%（Ph-Pe）、40.80%（Dh-Pe）和 90.30%（Ga-Pe），而其对果胶的抑制率从 3.11%（Na-Pe）增至 35.02%（Ph-Pe）、66.36%（Dh-Pe）和 77.89%（Ga-Pe）。此外，与 Na-Pe 相比，改性果胶表现出更好的乳化性能和更强的对大肠杆菌和金黄色葡萄球菌的抗菌活性。
