Abstract Chlorophyll (Chl) is a natural compound that is found in all autotrophic plants. Since phytophagous insects ingest the photosynthetically active material with the plant leaves, the question arises if and how herbivores deal with Chl and its degradation products. Here we review findings on Chl degradation in phytophagous insects and highlight the role of these ubiquitous plant metabolites for plant-feeding insects. Due to the anaerobic gut of many insects, the degradation is limited to the removal of the peripheral substituents, while the tetrapyrrole core remains intact. Proteins, such as red fluorescent protein, P252 (a novel 252-kDa protein), and chlorophyllide binding protein have been reported to occur in the insect gut and might be indirectly connected to Chl degradation. Besides of an nutritional value, e.g., by taking up Mg2+ ions or by sequestration of carbon from the phytol side chain, the Chl degradation products may serve the insect, after binding to certain proteins, as antimicrobial, antifungal, and antiviral factors. The protein complexes may also confer protection against reactive oxygen species. The antibiotic potential of proteins and degradation products does not only benefit phytophagous insects but also human being in medical application of cancer treatment for instance. This review highlights these aspects from a molecular, biochemical, and ecological point of view.

中文翻译：

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叶绿素在植食性昆虫中的命运超越了营养

摘要 叶绿素（Chlorophyll，Chl）是一种存在于所有自养植物中的天然化合物。由于植食性昆虫通过植物叶子摄取光合活性物质，因此出现了食草动物是否以及如何处理 Chl 及其降解产物的问题。在这里，我们回顾了植食性昆虫中 Chl 降解的发现，并强调了这些无处不在的植物代谢物对植食性昆虫的作用。由于许多昆虫的肠道厌氧，降解仅限于去除外围取代基，而四吡咯核心保持完整。据报道，昆虫肠道中存在蛋白质，例如红色荧光蛋白、P252（一种新型 252-kDa 蛋白）和叶绿素结合蛋白，可能与 Chl 降解间接相关。除了营养价值，例如，通过吸收 Mg2+ 离子或从植醇侧链中螯合碳，Chl 降解产物可以在与某些蛋白质结合后作为抗微生物、抗真菌和抗病毒因子为昆虫服务。蛋白质复合物还可以提供针对活性氧的保护。蛋白质和降解产物的抗生素潜力不仅有利于植食性昆虫，也有利于人类在癌症治疗等医学应用中的应用。这篇综述从分子、生物化学和生态学的角度强调了这些方面。蛋白质和降解产物的抗生素潜力不仅有利于植食性昆虫，也有利于人类在癌症治疗等医学应用中的应用。这篇综述从分子、生物化学和生态学的角度强调了这些方面。蛋白质和降解产物的抗生素潜力不仅有利于植食性昆虫，也有利于人类在癌症治疗等医学应用中的应用。这篇综述从分子、生物化学和生态学的角度强调了这些方面。