Diatoms are eukaryotic microalgae representing one of the major groups in the marine phytoplankton, accounting for up to 40% of annual productivity at sea. They are widely distributed in all aquatic environments, including extreme ones. To adapt and thrive in such different environments, diatoms have evolved several strategies, including the production of secondary metabolites and toxins as defence mechanisms. Despite the great ecological relevance of these organisms, the study of chemical interactions underlying intraspecific and interspecific communication is still an open field of research. To date, the best known example of chemical mediators in diatoms is represented by oxylipins. These compounds have multiple functions such as antipredator, antibacterial, infochemical and allelochemical, influencing the abundance and distribution of other species in the surrounding environments and eventually shaping the ecosystem functioning. Other lipidic compounds involved in chemical signalling in many organisms have been identified in diatoms, but their role in these microalgae is still poorly understood. In this review, we focus on lipidic secondary metabolites produced by diatoms, i.e. oxylipins, prostaglandins and sterols, their biosynthetic pathways and their established or putative role as infochemicals.

硅藻是真核微藻，代表海洋浮游植物的主要群体之一，占海洋年生产力的 40%。它们广泛分布在所有水生环境中，包括极端环境。为了在这种不同的环境中适应和茁壮成长，硅藻已经进化出几种策略，包括产生次级代谢物和毒素作为防御机制。尽管这些生物具有很大的生态相关性，但对种内和种间交流的化学相互作用的研究仍然是一个开放的研究领域。迄今为止，硅藻中最著名的化学介质例子是氧脂。这些化合物具有多种功能，如抗捕食、抗菌、信息化学和化感化学，影响周围环境中其他物种的丰度和分布，并最终塑造生态系统的功能。已经在硅藻中鉴定出参与许多生物体中化学信号传导的其他脂质化合物，但它们在这些微藻中的作用仍然知之甚少。在这篇综述中，我们关注由硅藻产生的脂质次生代谢物，即氧化脂、前列腺素和甾醇，它们的生物合成途径以及它们作为信息化学物质的既定或推定作用。