Rodios N A, Anteunis M J
J Antibiot (Tokyo). 1978 Apr;31(4):294-301. doi: 10.7164/antibiotics.31.294.
The interpretation of the 300 MHz 1H-nmr spectra of septamycin (1) and its sodium salt (1+) allow one to extract most of the parameters revealing their resemblant conformations in solution. The backbone forms a pseudocyclic structure closed by head-to-tail hydrogen bonding between the carboxylate fragment and the OH-14. In 1+, the sodium ion is trapped in a central hole by coordinating around it six to seven oxygen atoms (including COO-). The external lipophilic zone of the molecule keeps the sodium ion away from the surroundings. The dangling sugar-like fragment does not participate in the metal binding. It was not possible to detect any water molecule participating in the cyclization of septamycin-free acid, nor in septamycin-Na+, as was found in an X-ray study for the p-bromophenacyl ester.
对隔孢伏革菌素（1）及其钠盐（1+）的300 MHz 1H-核磁共振谱的解析，使人们能够提取出大部分揭示它们在溶液中相似构象的参数。主链形成了一个假环结构，通过羧酸盐片段与OH-14之间的头对头氢键封闭。在1+中，钠离子通过围绕其配位六到七个氧原子（包括COO-）被困在一个中心孔中。分子的外部亲脂区使钠离子与周围环境隔开。悬挂的类糖片段不参与金属结合。与对溴苯甲酰酯的X射线研究结果一样，无法检测到任何参与游离酸形式的隔孢伏革菌素或隔孢伏革菌素-钠环化的水分子。
