University of Belgrade, Faculty of Chemistry, Studentski Trg 16, P.O. Box 51, Belgrade, 11158, Serbia.
Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11000, Belgrade, Serbia.
Chemosphere. 2021 Jul;275:130005. doi: 10.1016/j.chemosphere.2021.130005. Epub 2021 Feb 17.
Polyethylene terephthalate (PET) is widely used material and as such became highly enriched in nature. It is generally considered inert and safe plastic, but due to the recent increased efforts to break-down PET using biotechnological approaches, we realized the scarcity of information about structural analysis of possible degradation products and their ecotoxicological assessment. Therefore, in this study, 11 compounds belonging to the group of PET precursors and possible degradation products have been comprehensively characterized. Seven of these compounds including 1-(2-hydroxyethyl)-4-methylterephthalate, ethylene glycol bis(methyl terephthalate), methyl bis(2-hydroxyethyl terephtahalate), 1,4-benzenedicarboxylic acid, 1,4-bis[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl] ester and methyl tris(2-hydroxyethyl terephthalate) corresponding to mono-, 1.5-, di-, 2,5- and trimer of PET were synthetized and structurally characterized for the first time. In-silico druglikeness and physico-chemical properties of these compounds were predicted using variety of platforms. No antimicrobial properties were detected even at 1000 μg/mL. Ecotoxicological impact of the compounds against marine bacteria Allivibrio fischeri proved that the 6 out of 11 tested PET-associated compounds may be classified as harmful to aquatic microorganisms, with PET trimer being one of the most toxic. In comparison, most of the compounds were not toxic on human lung fibroblasts (MRC-5) at 200 μg/mL with inhibiting concentration (IC50) values of 30 μg/mL and 50 μg/mL determined for PET dimer and trimer. Only three of these compounds including PET monomer were toxic to nematode Caenorhabditis elegans at high concentration of 500 μg/mL. In terms of the applicative potential, PET dimer can be used as suitable substrate for the screening, identification and characterization of novel PET-depolymerizing enzymes.
聚对苯二甲酸乙二醇酯（PET）是一种广泛使用的材料，因此在自然界中含量很高。它通常被认为是一种惰性和安全的塑料，但由于最近人们越来越努力地通过生物技术方法来分解 PET，我们意识到关于可能的降解产物的结构分析及其生态毒理学评估的信息十分匮乏。因此，在这项研究中，我们全面表征了属于 PET 前体和可能降解产物组的 11 种化合物。这些化合物中有 7 种包括 1-(2-羟乙基)-4-甲基对苯二甲酸酯、乙二醇双（对甲苯酸酯）、甲基双（2-羟乙基对苯二甲酸酯）、1,4-苯二甲酸、1,4-双[[4-（甲氧羰基）苯甲酰]氧基]乙基]酯和甲基三（2-羟乙基对苯二甲酸酯），它们分别对应于 PET 的单、1.5、二、2,5 和三聚体，首次被合成并进行了结构表征。使用各种平台预测了这些化合物的类药性和物理化学性质。即使在 1000μg/mL 的浓度下，也没有检测到抗菌性能。这些化合物对海洋细菌发光杆菌的生态毒性影响表明，在测试的 11 种与 PET 相关的化合物中，有 6 种可能被归类为对水生微生物有害，其中 PET 三聚体是最有毒的一种。相比之下，大多数化合物在 200μg/mL 时对人肺成纤维细胞（MRC-5）没有毒性，PET 二聚体和三聚体的抑制浓度（IC50）值分别为 30μg/mL 和 50μg/mL。在高浓度 500μg/mL 时，只有三种化合物，包括 PET 单体，对秀丽隐杆线虫有毒性。就应用潜力而言，PET 二聚体可用作筛选、鉴定和表征新型 PET 解聚酶的合适底物。
