Fukaya Mitsunori, Nagamine Shota, Ozaki Taro, Liu Yaping, Ozeki Miina, Matsuyama Taro, Miyamoto Kazunori, Kawagishi Hirokazu, Uchiyama Masanobu, Oikawa Hideaki, Minami Atsushi
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.
Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
Angew Chem Int Ed Engl. 2023 Oct 26;62(44):e202308881. doi: 10.1002/anie.202308881. Epub 2023 Sep 26.
Mushroom terpenoids are biologically and chemically diverse fungal metabolites. Among them, melleolides are representative sesquiterpenoids with a characteristic protoilludane skeleton. In this study, we applied a recently established hot spot knock-in method to elucidate the biosynthetic pathway leading to 1α-hydroxymelleolide. The biosynthesis of the sesquiterpene core involves the cytochrome P450 catalyzing stepwise hydroxylation of the Δ -protoilludene framework and a stereochemical inversion process at the C5 position catalyzed by short-chain dehydrogenase/reductase family proteins. The highlight of the biosynthesis is that the flavoprotein Mld7 catalyzes an oxidation-triggered double-bond shift accompanying dehydration and acyl-group-assisted substitution with two different nucleophiles at the C6 position to afford the Δ -protoilludene derivatives, such as melleolide and armillarivin. The complex reaction mechanism was proposed by DFT calculations. Of particular importance is that product distribution is regulated by interaction with the cell membrane.
蘑菇萜类化合物是具有生物和化学多样性的真菌代谢产物。其中，蜜环菌素是具有特征性原伊鲁烷骨架的代表性倍半萜类化合物。在本研究中，我们应用了最近建立的热点敲入方法来阐明导致1α-羟基蜜环菌素的生物合成途径。倍半萜核心的生物合成涉及细胞色素P450催化Δ-原伊鲁烯骨架的逐步羟基化以及短链脱氢酶/还原酶家族蛋白催化的C5位立体化学反转过程。生物合成的亮点在于黄素蛋白Mld7催化氧化引发的双键迁移，同时伴随脱水以及在C6位由两个不同亲核试剂进行的酰基辅助取代反应，从而生成Δ-原伊鲁烯衍生物，如蜜环菌素和亮菌甲素。通过密度泛函理论计算提出了复杂的反应机制。特别重要的是，产物分布受与细胞膜相互作用的调控。
