Quaternary ammonium compounds (QACs) are a class of cationic surfactants routinely used for the disinfection of industries, institutions and households, and have seen a sharp increase in use during the COVID-19 pandemic. However, current commercial QACs consist of only stable chemical bonds such as C–N, C–C, and C–H, which makes their natural degradation rather difficult. Recent studies suggest that emerging negative environmental impacts, such as systemic antibiotics resistance and toxicity to living organisms, are directly associated with prolonged exposure to QACs. Here we report a new class of QAC which contains relatively volatile chemical functional groups such as ester and thioether bonds. Degradation kinetics in aqueous solutions suggests that the stability of these QACs depends not only on their intrinsic hydrophobicity but also on external environmental factors such as pH, temperature and ion presence. The microbicidal effects of QACs containing carbon chains with various lengths were also tested, one of which, named “Ephemora”, is highly active against a broad spectrum of microbes including fungi, bacteria and viruses, for instance, methicillin-resistant Staphylococcus aureus (MRSA). The easy synthesis and purification of Ephemora starting from inexpensive commercially available reagents, together with its excellent antimicrobial activity and ability to degrade in natural waters over time, make its large-scale commercial production possible.

中文翻译：

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环境可降解季铵盐的设计与生产

季铵化合物 (QAC) 是一类常用于工业、机构和家庭消毒的阳离子表面活性剂，在 COVID-19 大流行期间使用量急剧增加。然而，目前商业化的 QAC 仅由稳定的化学键组成，如 C-N、C-C 和 C-H，这使得它们的自然降解相当困难。最近的研究表明，新出现的负面环境影响，例如全身性抗生素耐药性和对生物体的毒性，与长期接触 QAC 直接相关。在这里，我们报告了一类新的 QAC，它包含相对易挥发的化学官能团，如酯键和硫醚键。水溶液中的降解动力学表明，这些 QAC 的稳定性不仅取决于其固有的疏水性，还取决于外部环境因素，如 pH 值、温度和离子的存在。还测试了含有不同长度碳链的 QAC 的杀菌效果，其中一种名为“Ephemora”，对包括真菌、细菌和病毒在内的广谱微生物具有高度活性，例如耐甲氧西林金黄色葡萄球菌(MRSA)。从廉价的市售试剂开始，Ephemora 易于合成和纯化，再加上其优异的抗菌活性和在天然水中随时间降解的能力，使其大规模商业生产成为可能。