Pseudoceratins A and B, antifungal bicyclic bromotyrosine-derived metabolites from the marine sponge Pseudoceratina purpurea
Pseudoceratins A and B, antifungal bicyclic bromotyrosine-derived metabolites from the marine sponge Pseudoceratina purpurea
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DOI：
10.1021/jo062010
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发表时间：
2007-02-16
影响因子：
3.6
通讯作者：
Matsunaga, Shigeki
中科院分区：
文献类型：
--
作者：
Jang, Jae-Hyuk;van Soest, Rob W. M.;Matsunaga, Shigeki
假角虫A(1)和B(2)是从海绵刺青中分离得到的。假角蛋白在大量溴酪氨酸衍生的海绵代谢物中是独一无二的，因为它具有芳香环的取代模式、螺缩醛和肟醚官能团的存在以及1,5-二氨基-1,5-二脱氧-d -阿拉伯糖醇系链。假角蛋白A(1)和B(2)在系链的取向上不同。通过光谱数据分析确定了它们的结构。由于桥接结构导致化合物的刚性，使得ROESY/NOESY光谱具有许多跨环交叉峰，从而可以确定1和2的相对立体化学性质。通过将酸水解产物中分离的片段转化为Mosher's酯，并将H-1 NMR谱与标准样品的H-1 NMR谱进行比较，确定了1,5-二氨基-1,5-二脱氧阿拉伯糖醇单元的d构型。假角蛋白对白色念珠菌具有明显的抗真菌活性。
Pseudoceratins A (1) and B (2) have been isolated from the marine sponge Pseudoceratina purpurea. Pseudoceratins are unique among the large class of bromotyrosine-derived sponge metabolites with respect to the substitution pattern of aromatic rings and the presence of spiroacetal and oxime ether functional groups as well as an 1,5-diamino-1,5-dideoxy-D-arabitol tether. Pseudoceratins A (1) and B (2) are epimeric differing in the orientation of the tether. Their structures were determined by analysis of spectral data. The rigidity of the compounds arising from their bridged structure gave ROESY/NOESY spectra with many transannular cross-peaks, which allowed the assignment of the relative stereochemistry of 1 and 2 to be established. The D-configuration of the 1,5-diamino-1,5-dideoxyarabitol unit was determined by converting the fragment isolated from the acid hydrolysate to the Mosher's ester and compared the H-1 NMR spectrum with those of standard samples. Pseudoceratins exhibited significant antifungal activity against Candida albicans.