PDF(Pubmed)
Abstract：
Subjecting the Australian marine-derived fungus Aspergillus noonimiae CMB-M0339 to cultivation profiling using an innovative miniaturized 24-well plate format (MATRIX) enabled access to new examples of the rare class of 2,6-diketopiperazines, noonazines A-C (1-3), along with the known analogue coelomycin (4), as well as a new azaphilone, noonaphilone A (5). Structures were assigned to 1-5 on the basis of a detailed spectroscopic analysis, and in the case of 1-2, an X-ray crystallographic analysis. Plausible biosynthetic pathways are proposed for 1-4, involving oxidative Schiff base coupling/dimerization of a putative Phe precursor. Of note, 2 incorporates a rare meta-Tyr motif, typically only reported in a limited array of Streptomyces metabolites. Similarly, a plausible biosynthetic pathway is proposed for 5, highlighting a single point for stereo-divergence that allows for the biosynthesis of alternate antipodes, for example, the 7R noonaphilone A (5) versus the 7S deflectin 1a (6).
摘要：
使用创新的微型化24孔板格式（MATRIX）对澳大利亚海洋衍生的真菌Noronimiae曲霉CMB-M0339进行培养分析，从而可以获得罕见的2,6-二酮哌嗪类的新实例，noonazineA-C（1-3），连同已知的类似物coelomycin（4），以及一种新的氮杂菲酮,noonaphiloneA(5).根据详细的光谱分析将结构分配给1-5，在1-2的情况下，X射线晶体学分析。1-4提出了合理的生物合成途径，涉及推定的Phe前体的氧化席夫碱偶联/二聚化。值得注意的是，2包含一个罕见的meta-Tyr图案，通常仅在有限的链霉菌代谢物中报告。同样，提出了一个合理的生物合成途径5，突出了一个单一的点的立体发散，允许生物合成的替代对映体，例如,7R诺芬酮A（5）与7Sdeflectin1a（6）。
