A new structural theme in the imidazole-containing alkaloids from a calcareous Leucetta sponge
A new structural theme in the imidazole-containing alkaloids from a calcareous Leucetta sponge
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DOI：
10.1021/jo048789
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发表时间：
2004-12-24
影响因子：
3.6
通讯作者：
Crews, P
中科院分区：
文献类型：
--
作者：
Ralifo, P;Crews, P
对斐济海绵Leucetta sp.的进一步研究，作为（+）-卡定A（4）和（-）螺卡定A（5）和B（6）的来源，已经产生了（-）-螺亮氨蝶呤（8），这是第一种含有稠合的2-氨基咪唑双胍环的天然产物，沿着已知的化合物N，N-二甲基甲脒D（3）和异索纳胺B（7）。NMR分析允许8的明确的2D结构归属，并且通过ROESY数据确定其相对立体化学。观察到8对肠球菌的良好抗菌活性，MIC小于6.25 μ g/mL。
Further study of the Fijian sponge Leucetta sp., a source of (+)-calcaridine A (4) and (-)spirocalcaridines A (5) and B (6), has yielded (-)-spiroleucettadine (8), the first natural product to contain a fused 2-aminoimidazole oxalane ring along with the known compounds NN-dimethylnaamidine D (3) and isonaamine B (7). NMR analysis allowed the unambiguous 2D structural assignment of 8, and its relative stereochemistry was determined by ROESY data. Good antibacterial activity was observed for 8 against Enterococcus durans with an MIC of less than 6.25 mug/mL.