Itaconic acid possessing a vinylidene group, which is mainly produced by fungi, is used as a biobased platform chemical and shows distinctive bioactivities. On the other hand, some fungi and lichens produce itaconic acid derivatives possessing itaconic acid skeleton, and the number of the derivatives is currently more than seventy. Based on the molecular structures, they can be categorized into two groups, alkylitaconic acids and α-methylene-γ-butyrolactones. Interestingly, some itaconic acid derivatives show versatile functions such as antimicrobial, anti-inflammatory, antitumor, and plant growth-regulating activities. The vinylidene group of itaconic acid derivatives likely participates in these functions. It is suggested that α-methylene-γ-butyrolactones are biosynthesized from alkylitaconic acids which are first biosynthesized from acyl-CoA and oxaloacetic acid. Some modifying enzymes such as hydroxylase and dehydratase are likely involved in the further modification after biosynthesis of their precursors. This contributes to the diversity of itaconic acid derivatives. In this review, we summarize their structures, functions, and biosynthetic pathways together with a discussion of a strategy for the industrial use. KEY POINTS: • Itaconic acid derivatives can be categorized into alkylitaconic acids and α-methylene-γ-butyrolactones. • The vinylidene group of itaconic acid derivatives likely participates in their versatile function. • It is suggested that α-methylene-γ-butyrolactones are biosynthesized from alkylitaconic acids which are first synthesized from acyl-CoA and oxaloacetic acid.

中文翻译：

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衣康酸衍生物：结构，功能，生物合成和观点。

具有亚乙烯基的衣康酸主要由真菌产生，被用作生物基平台化学品并显示出独特的生物活性。另一方面，一些真菌和地衣产生具有衣康酸骨架的衣康酸衍生物，并且目前衍生物的数目超过七十。根据分子结构，它们可分为两类，烷基衣康酸和α-亚甲基-γ-丁内酯。有趣的是，一些衣康酸衍生物显示出多种功能，例如抗微生物，抗炎，抗肿瘤和植物生长调节活性。衣康酸衍生物的亚乙烯基可能参与这些功能。建议α-亚甲基-γ-丁内酯是由烷基衣康酸生物合成的，而后者首先是由酰基辅酶A和草酰乙酸生物合成的。生物合成其前体后，一些修饰酶（例如羟化酶和脱水酶）可能参与进一步修饰。这有助于衣康酸衍生物的多样性。在这篇综述中，我们总结了它们的结构，功能和生物合成途径，并讨论了工业使用策略。要点：•衣康酸衍生物可分为烷基衣康酸和α-亚甲基-γ-丁内酯。•衣康酸衍生物的亚乙烯基可能参与了其多功能性。