Moreno-Vásquez María J, Carretas-Valdez Manuel I, Luque-Alcaraz Ana G, Quintero-Reyes Idania E, Tapia-Hernández José A, Arvizu-Flores Aldo A, Moreno-Córdova Elena N, Graciano-Verdugo Abril Z
Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, 83000, México.
Departamento de Ciencias de la Salud, Universidad de Sonora, Cd. Obregón, 85040, México.
Curr Microbiol. 2024 Jul 13;81(9):264. doi: 10.1007/s00284-024-03776-9.
One of the main interests in the food industry is the preservation of food from spoilage by microorganisms or lipid oxidation. A novel alternative is the development of additives of natural origin with dual activity. In the present study, a chemically modified lysozyme (Lys) with epigallocatechin gallate (EGCG) was developed to obtain a conjugate (Lys-EGCG) with antibacterial/antioxidant activity to improve its properties and increase its application potential. The modification reaction was carried out using a free radical grafting method for the Lys modification reaction, using ascorbic acid and hydrogen peroxide as radical initiators in an aqueous medium. The synthesis of Lys-EGCG conjugate was confirmed by spectroscopic (FT-IR, H-RMN, and XPS) and calorimetry differential scanning (DSC) analyses. The EGCG binding to the Lys biomolecule was quantified by the Folin-Ciocalteu method; the antibacterial activity was evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MCB) against Staphylococcus aureus and Pseudomonas fluorescens; the antioxidant activity was evaluated by ABTS, DPPH, and FRAP. The spectroscopic results showed that the Lys-EGCG conjugate was successfully obtained, and the DSC analysis revealed a 20 °C increase (P < 0.05) in the denaturation temperature of Lys due to EGCG modification. The EGCG concentration in Lys-EGCG was 97.97 ± 4.7 µmol of EGCG/g of sample. The antibacterial and antioxidant activity of the Lys-EGCG conjugate was higher (P < 0.05) than pure EGCG and Lys. The chemical modification of Lys with EGCG allows for the bioconjugate with a dual function (antibacterial/antioxidant), broadening the range of Lys and EGCG applications to different areas such as food, cosmetic, and pharmaceutical industries.
食品工业的主要关注点之一是防止食品因微生物或脂质氧化而变质。一种新的替代方法是开发具有双重活性的天然来源添加剂。在本研究中，开发了一种用表没食子儿茶素没食子酸酯（EGCG）化学修饰的溶菌酶（Lys），以获得具有抗菌/抗氧化活性的共轭物（Lys-EGCG），从而改善其性能并增加其应用潜力。修饰反应采用自由基接枝法进行Lys修饰反应，在水介质中使用抗坏血酸和过氧化氢作为自由基引发剂。通过光谱分析（傅里叶变换红外光谱、氢核磁共振光谱和X射线光电子能谱）和差示扫描量热法（DSC）分析证实了Lys-EGCG共轭物的合成。通过福林-酚试剂法对EGCG与Lys生物分子的结合进行了定量；通过对金黄色葡萄球菌和荧光假单胞菌的最低抑菌浓度（MIC）和最低杀菌浓度（MCB）评估抗菌活性；通过ABTS、DPPH和FRAP评估抗氧化活性。光谱结果表明成功获得了Lys-EGCG共轭物，DSC分析显示由于EGCG修饰，Lys的变性温度升高了20℃（P<0.05）。Lys-EGCG中EGCG的浓度为97.97±4.7μmol EGCG/g样品。Lys-EGCG共轭物的抗菌和抗氧化活性高于纯EGCG和Lys（P<0.05）。用EGCG对Lys进行化学修饰可得到具有双重功能（抗菌/抗氧化）的生物共轭物，拓宽了Lys和EGCG在食品、化妆品和制药等不同领域的应用范围。
