Graduate School of Pharmaceutical Sciences, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
J Nat Prod. 2014 Jan 24;77(1):154-8. doi: 10.1021/np400668k. Epub 2013 Dec 13.
A cyclic peptide was isolated from the deep-sea marine sponge Discodermia japonica, and its NMR spectroscopic data were identical to those reported for cyclolithistide A, a known antifungal depsipeptide. However, the interresidue HMBC correlations suggested that the amino acid sequence was different from that of the original structure. Moreover, chiral-phase GC-MS, combined with Marfey's analysis, indicated that the absolute configurations of three amino acids were also antipodal. Here, we propose the revised structure of cyclolithistide A and address the configuration of the previously unassigned 4-amino-3,5-dihydroxyhexanoic acid (Adha) moiety.
从深海海绵 Discodermia japonica 中分离得到一种环肽，其 NMR 波谱数据与已知抗真菌的环硫肽 A 的报道数据完全相同。然而，残基间的 HMBC 相关表明其氨基酸序列与原始结构不同。此外，手性柱 GC-MS 结合 Marfey 分析表明，三个氨基酸的绝对构型也是对映体。在此，我们提出了环硫肽 A 的修订结构，并确定了以前未指定的 4-氨基-3,5-二羟基己酸（Adha）部分的构型。
