Keller-Juslén C, King H D, Kuhn M, Loosli H R, von Wartburg A
J Antibiot (Tokyo). 1978 Sep;31(9):820-8. doi: 10.7164/antibiotics.31.820.
Noboritomycins A and B, two new polycyclic ionophoric polyethers were isolated from a strain of Streptomyces noboritoensis. The crystal structure and absolute configuration of noboritomycin A were established by X-ray analysis of its silver salt C43/63O14Ag. Noboritomycin A is the first metabolic polyether possessing two carboxylic acid functions on the carbon backbone (C-31), namely a free acid and an additional carboxylic acid ethylester group. An unusual spiroketal system as well as a salicylic acid chromophore represent further remarkable elements. Noboritomycin A shows in this respect a structural relationship to salinomycin and lasalocid respectively. Comparison of physico-chemical data, in particular the interpretation of the 1H- and 13C-NMR spectra, revealed that noboritomycins A and B are structurally closely related, noboritomycin B carrying an ethyl substituent on the aromatic ring in the place of a methyl group present in noboritomycin A. Both metabolites exhibit activity against Gram-positive bacteria and against Eimeria tenella (chicken coccidiosis).
从诺博里托链霉菌菌株中分离出了两种新的多环离子载体聚醚——诺博里霉素A和B。通过对其银盐C43/63O14Ag进行X射线分析，确定了诺博里霉素A的晶体结构和绝对构型。诺博里霉素A是第一种在碳骨架（C-31）上具有两个羧酸官能团的代谢聚醚，即一个游离酸和一个额外的羧酸乙酯基团。一个不寻常的螺缩酮系统以及一个水杨酸发色团是另外的显著结构单元。在这方面，诺博里霉素A分别与盐霉素和拉沙洛西表现出结构关系。物理化学数据的比较，特别是对1H-和13C-NMR光谱的解释表明，诺博里霉素A和B在结构上密切相关，诺博里霉素B在芳香环上带有一个乙基取代基，取代了诺博里霉素A中的一个甲基。这两种代谢产物均对革兰氏阳性菌和柔嫩艾美耳球虫（鸡球虫病）具有活性。
