The Cytosporones, New Octaketide Antibiotics Isolated from an Endophytic Fungus
作者:Sean F. Brady、Melissa M. Wagenaar、Maya P. Singh、Jeff E. Janso、Jon Clardy
DOI:10.1021/ol006680s
日期:2000.12.1
Organic extracts from cultures of endophytic fungi collected in the Guanacaste Conservation Area of Costa Rica were screened for antibiotic activity. Two endophytes CR200 (Cytospora sp,) and CR146 (Diaporthe sp,) were found to have potent antibiotic activity. Bioassay guided fractionation of the extracts from these fungi led to the identification of cytosporones D and E, antibacterial active trihydroxybenzene lactones, and three related but inactive metabolites, The five new octaketides were characterized using X-ray crystallography and NMR.
Biosynthesis of Cytosporones in Leotiomycetous Filamentous Fungi
作者:Li Li、Weimao Zhong、Hang Liu、Patricia Espinosa-Artiles、Ya-ming Xu、Chen Wang、Jose Manuel Verdugo Robles、Tiago Antunes Paz、Marielle Cascaes Inácio、Fusheng Chen、Yuquan Xu、A. A. Leslie Gunatilaka、István Molnár
DOI:10.1021/jacs.3c14066
日期:2024.3.6
isochroman-3-one pharmacophore are rare among fungal natural products as their biosynthesis requires an unorthodox S-type aromatic ring cyclization. Genome mining uncovered a conserved gene cluster in select leotiomycetous fungi that encodes the biosynthesis of cytosporones, including isochroman-3-one congeners. Combinatorial biosynthesis in total biosynthetic and biocatalytic formats in Saccharomyces cerevisiae
具有异色满-3-酮药效基团的聚酮化合物在真菌天然产物中很少见,因为它们的生物合成需要非正统的 S 型芳环环化。基因组挖掘在选定的leotiomycetous真菌中发现了一个保守的基因簇,该基因簇编码细胞孢子酮的生物合成,包括isochroman-3-one同源物。酿酒酵母中全生物合成和生物催化形式的组合生物合成以及使用纯化酶的关键反应的体外重建揭示了细胞孢子酮结构和生物活性多样性是如何产生的。细胞孢子酮的 S 型酰基二羟基苯乙酸 (ADA) 核心由协作的聚酮合酶对组装。硫酯酶结构域催化的酯交换反应释放 ADA 酯,其中一些是已知的 Nur77 调节剂。或者,水解释放允许 C6 通过黄素依赖性单加氧酶羟基化,产生三羟基苯部分。通过短链脱氢酶/还原酶还原 C9 羰基会引发 isochroman-3-one 形成,从而提供具有细胞毒性和抗菌活性的细胞孢子酮。烯酰二-或三羟基苯乙酸作为分流产物生成,而异可尔曼-3