Monocyclic phenols and catechols are important antioxidant compounds for the food and pharmaceutic industries; their production through biotransformation of low-added value starting compounds is of major biotechnological interest. The toluene o-xylene monooxygenase (ToMO) from Pseudomonas sp. OX1 is a bacterial multicomponent monooxygenase (BMM) that is able to hydroxylate a wide array of aromatic compounds and has already proven to be a versatile biochemical tool to produce mono- and dihydroxylated derivatives of aromatic compounds. The molecular determinants of its regioselectivity and substrate specificity have been thoroughly investigated, and a computational strategy has been developed which allows designing mutants able to hydroxylate non-natural substrates of this enzyme to obtain high-added value compounds of commercial interest. In this work, we have investigated the use of recombinant ToMO, expressed in cells of Escherichia coli strain JM109, for the biotransformation of non-natural substrates of this enzyme such as 2-phenoxyethanol, phthalan and 2-indanol to produce six hydroxylated derivatives. The hydroxylated products obtained were identified, isolated and their antioxidant potential was assessed both in vitro, using the DPPH assay, and on the rat cardiomyoblast cell line H9c2. Incubation of H9c2 cells with the hydroxylated compounds obtained from ToMO-catalyzed biotransformation induced a differential protective effect towards a mild oxidative stress induced by the presence of sodium arsenite. The results obtained confirm once again the versatility of the ToMO system for oxyfunctionalization reactions of biotechnological importance. Moreover, the hydroxylated derivatives obtained possess an interesting antioxidant potential that encourages the use of the enzyme for further functionalization reactions and their possible use as scaffolds to design novel bioactive molecules.
单环
酚和
儿茶酚是食品和制药工业中重要的抗氧化化合物;通过低附加值起始化合物的
生物转化生产它们具有重要的
生物技术意义。来自假单胞菌OX1的
甲苯o-二
甲苯单氧酶(ToMO)是一种细菌多组分单氧酶(BMM),能够对多种芳香化合物进行羟基化,已经证明它是一个多功能的生化工具,用于生产芳香化合物的单羟基化和二羟基化衍
生物。其区域选择性和底物特异性的分子决定因素已被深入研究,并开发了一种计算策略,能够设计变异体以羟基化该酶的非天然底物,以获得具有商业价值的高附加值化合物。在本研究中,我们探讨了在大肠杆菌JM109株中表达的
重组ToMO用于非天然底物的
生物转化,例如2-苯氧基
乙醇、
邻苯二甲酸酐和
2-茚醇,以生产六种羟基化衍
生物。所获得的羟基化产品被识别、分离,并评估了它们的抗氧化潜力,既进行了体外试验(使用
DPPH法),又在大鼠心肌母
细胞系H9c2上进行了评估。将H9c2细胞与由ToMO催化的
生物转化获得的羟基化化合物进行孵育,诱导了对由
亚砷酸钠引发的轻度氧化应激的差异性保护效应。获得的结果再次确认了ToMO系统在
生物技术重要的氧功能化反应中的多功能性。此外,所获得的羟基化衍
生物具有有趣的抗氧化潜力,鼓励使用该酶进行进一步的功能化反应,并可能作为设计新
生物活性分子的支架。