Henkel T, Rohr J, Beale J M, Schwenen L
Institut für Organische Chemie, Universität Göttingen, W. Germany.
J Antibiot (Tokyo). 1990 May;43(5):492-503. doi: 10.7164/antibiotics.43.492.
The chemical structure of the new angucycline antibiotic landomycin A has been elucidated via chemical and spectroscopic methods, in particular by 2D NMR correlation spectroscopy, e.g., 1H, 1H-COSY, 13C, 1H-COSY, correlation spectroscopy via long-range-couplings and heteronuclear multiple bond connectivity spectroscopy sequences. The spectroscopic investigations were carried out principally with the octaacetyl derivative of landomycin A, which is more soluble in organic solvents than landomycin A itself. The structure consists of a new, unusual angucyclinone, landomycinone A, and of six deoxy sugars, four D-olivoses and two L-rhodinoses, which are all assembled in one chain thus forming the sequence (olivose-4----1-olivose-3----1-rhodinose)2. This long sugar chain is bonded as a phenolic glycoside to the aglycone moiety, a unique structural feature among quinone glycoside antibiotics. By comparison with the main component landomycin A, the structures of three minor congeners, namely landomycins B, C and D, could be proposed.
新型蒽环类抗生素兰卡霉素A的化学结构已通过化学和光谱方法得以阐明，特别是借助二维核磁共振相关光谱，例如1H, 1H-COSY、13C, 1H-COSY、远程耦合相关光谱以及异核多键连接光谱序列。光谱研究主要针对兰卡霉素A的八乙酰基衍生物进行，该衍生物在有机溶剂中的溶解度比兰卡霉素A本身更高。其结构由一种新型、不同寻常的蒽环酮——兰卡霉素酮A，以及六种脱氧糖组成，其中包括四个D-橄榄糖和两个L-鼠李糖，它们全部连接在一条链上，从而形成序列(橄榄糖-4----1-橄榄糖-3----1-鼠李糖)2。这条长糖链作为酚糖苷与苷元部分相连，这是醌糖苷类抗生素中独特的结构特征。通过与主要成分兰卡霉素A进行比较，可推测出三种次要同系物，即兰卡霉素B、C和D的结构。
