Investigation of a Lipase-Catalyzed Reaction between Pectin and Salicylic Acid and Its Isomers and Evaluation of the Emulsifying Properties, Antioxidant Activities, and Antibacterial Activities of the Corresponding Products

Abstract

This study presents a method for modifying pectin with phenolic acids catalyzed by lipase in a two-phase system of water/tetrahydrofuran. Salicylic acid (SA) and its isomers, including m-hydroxybenzoic acid (MHBA) and p-hydroxybenzoic acid (PHBA), were grafted onto pectin, and the products were characterized via UV–vis, Fourier transform infrared spectroscopy (FTIR), and 1H NMR analyses to explore the reaction process and mechanism between pectin and the three phenolic acids. Results indicated that lipase played a dual role in the reaction, namely, catalyzing the hydrolysis of the methyl group in the aqueous phase and esterifying the carboxyl group of pectin with the phenolic hydroxyl group of the phenolic acids in tetrahydrofuran. The grafting ratio of SA-modified pectin, MHBA-modified pectin, and PHBA-modified pectin was 1.89, 10.58, and 20.32%, respectively, and it was affected by the position of phenolic hydroxyl. Moreover, the effects of phenolic acids on the emulsifying properties, antioxidant activities, and antibacterial activities of the native and modified pectins were evaluated. In several aspects, the emulsifying properties of the modified pectins were better than those of native pectin. Moreover, the grafting of phenolic acids only slightly affected the 1,1-diphenyl-2-picryl hydrazine (DPPH) clearance of the modified pectins but substantially improved their inhibition ratio in a β-carotene bleaching assay. Furthermore, the modified pectins exhibited better bacteriostatic activity against both Escherichia coli and Staphylococcus aureus than native pectin.

Ferulic acid‐ and gallic ester‐acylated pectin: Preparation and characterization

“…Fa and trans-Fa only have one hydroxyl group that is para-substituted on the aromatic ring. In the case of MG and EG, there are three hydroxyl groups that are paraand ortho-substituted on the aromatic ring (Chen et al, 2011;Huang et al, 2021). The presence of more hydroxyl groups in the para and ortho positions was reported to enhance the antioxidative activity because of additional resonance stabilization (Liu et al, 2014).…”

“…Pectin is a complex polysaccharide found in cell walls and middle lamellae of higher plants (Muoz-almagro et al, 2021), which can be used as a novel functional material to replace the traditional drug delivery bio-materials in food and pharmaceutical applications (Abid, et al, 2017;Huang et al, 2021Huang et al, , 2022Moslemi, 2021). However, the special macromolecular structure of pectin and its hydrogen atom donor deficiency lead to insufficient biological activities, thus severely limiting its application (Ciriminna et al, 2022;Muthukumaran et al, 2018).…”

Recent advances in the enzymatic synthesis of lipophilic antioxidant and antimicrobial compounds

“…Another example of the modification of polysaccharides can be found in the paper of Zhang et al ( 2021 ). The authors investigated the lipase-catalyzed reaction between pectin and o -hydroxybenzoic, m -hydroxybenzoic or p -hydroxybenzoic acids in a two-phase system, and the emulsifying, antioxidant and antibacterial properties of the synthesized derivatives were evaluated.…”

“…The substituent location was also crucial for emulsifying properties, increasing the inhibition ratio in the β-carotene bleaching assay and the antibacterial activity against E. coli and S. aureus . Modified pectins turned out to be interesting and perspective compounds, and especially the p -hydroxybenzoic derivative of pectin can find industrial application as a multitasking (antioxidant, antibacterial and emulsifying agent) compound in the near future (Zhang et al 2021 ).…”

Chemical modification of pectin and polygalacturonic acid: A critical review

“…Gallic acid was bound via its 4-OH group with the C6 carboxylate of pectin employing a lipase (Novozyme 435, from Aspergillus niger) in a water/tetrahydrofuran mixture at 50 °C. Subsequently p/m/o-hydroxybenzoic acid and 3,4-dihydroxy benzoic acid have been reacted in a similar manner (Scheme 4, Zhang et al 2020b). The materials obtained have been tested for their emulsifying properties as well as their antioxidant and antibacterial activities.…”