One new cyclic heptapeptide containing non-proteinogenic amino acid residues kynurenine and γ-aminobutyric acid, named unguisin G, as well as three known congeners unguisins A, E and F, were isolated from a sponge-derived fungus Aspergillus candidus NF2412. The structures were elucidated by comprehensive spectroscopic analyses of HRESIMS and NMR data. The absolute configuration of amino acid residues of 1 was determined by advanced Marfey’s method. All compounds were evaluated on antimicrobial activities against nine pathogens by the agar diffusion method.

中文翻译：

---

Unguisin G，一种新的含有犬尿氨酸的环状七肽，来自海绵相关真菌念珠菌曲霉NF2412

从海绵衍生的真菌曲霉Aspergillus candidus NF2412中分离出一种新的含有非蛋白氨基酸残基犬尿氨酸和γ-氨基丁酸的环状七肽，称为unguisin G，以及三个已知的同类素unguisins A，E和F。通过对HRESIMS和NMR数据进行全面的光谱分析来阐明其结构。1的氨基酸残基的绝对构型通过先进的Marfey方法确定。通过琼脂扩散法评估所有化合物对九种病原体的抗菌活性。