Bifunctional\nSesquiterpene/Diterpene Synthase Agr2\nfrom Cyclocybe aegerita Gives Rise\nto the Novel Diterpene Cyclocybene

Cyclocybe aegerita is\na model mushroom\nbelonging to the fungal phylum Basidiomycota. Among others, C. aegerita is known for its diverse terpenome, containing\nvarious volatile and nonvolatile terpenes and terpenoids. Here, we\ndeepen the knowledge on their biosynthetic pathways by studying the\nterpene synthase Agr2 in detail. In contrast to previous studies,\nthe heterologous production of Agr2 in the agaric host Coprinopsis cinerea revealed the production of two\nterpenes, one of which was the already known sesquiterpene viridiflorene.\nThe other one was a so far unknown diterpene that had to be isolated\nand purified by means of preparative RP-HPLC for structure elucidation.\n1D- and 2D-NMR experiments revealed the compound as the novel diterpene\ncyclocybene, pointing to the bifunctionality of Agr2 to produce both\na sesquiterpene and a diterpene.