Hirayama N, Shirahata K, Ohashi Y, Sasada Y
Mol Pharmacol. 1983 Jan;23(1):127-32.
The fortimicins are pseudodisaccharide antibiotics consisting of purpurosamine and fortamine moieties which are connected through an alpha-linkage. NMR spectra indicate that the fortamine ring in fortimicin A takes a chair conformation which corresponds to an inverted one in the conformation of fortimicin B free base. Fortimicin A is unstable in solution, and we were unable to obtain any crystals of it. To elucidate the structure of fortimicin A and to clarify the stereochemistry of fortimicins, we have undertaken to calculate their empirical force-fields starting from the X-ray structures of fortamines and fortimicin B free base. Nuclear Overhauser enhancement data were also employed to confirm the calculated relative orientation of the two rings around the glycosidic linkage. The 3-dimensional structure-activity relationship of aminoglycoside antibiotics is discussed on the basis of these results.
福提霉素是由紫罗胺和福他胺部分通过α-连接相连的假二糖抗生素。核磁共振光谱表明，福提霉素A中的福他胺环呈椅式构象，这与福提霉素B游离碱构象中的反转构象相对应。福提霉素A在溶液中不稳定，我们无法获得其任何晶体。为了阐明福提霉素A的结构并明确福提霉素的立体化学，我们已着手从福他胺和福提霉素B游离碱的X射线结构出发计算它们的经验力场。核Overhauser增强数据也被用于确认糖苷键周围两个环的计算相对取向。基于这些结果讨论了氨基糖苷类抗生素的三维构效关系。
