Godoy-Alcántar C, Rivera I L, Yatsimirsky A K
Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico.
Bioorg Med Chem Lett. 2001 Mar 12;11(5):651-4. doi: 10.1016/s0960-894x(01)00025-7.
A bicyclic polypeptide antibiotic thiostrepton forms both 1:1 and 1:2 complexes with anions (as tetrabutylammonium salts) in organic solvents with K2 >K1 for F- and K2<<K1 for all other anions studied. Relative stabilities of 1:1 complexes in DMSO are AcO- approximatelyF->>Cl-, Br-, HSO4-, H2PO4-, but in CHCl3 they follow a different order: Cl- approximatelyHSO4- >F- approximately AcO- > Br > H2PO4-. The binding mode of anions to thiostrepton is discussed on the basis of solvent effects on the complexation selectivity.
双环多肽抗生素硫链丝菌素在有机溶剂中与阴离子(以四丁基铵盐形式)形成1:1和1:2的络合物,对于氟离子,K2>K1,而对于所有其他研究的阴离子,K2<<K1。在二甲基亚砜中,1:1络合物的相对稳定性为醋酸根离子≈氟离子>>氯离子、溴离子、硫酸氢根离子、磷酸二氢根离子,但在三氯甲烷中,它们遵循不同的顺序:氯离子≈硫酸氢根离子>氟离子≈醋酸根离子>溴离子>磷酸二氢根离子。基于溶剂对络合选择性的影响,讨论了阴离子与硫链丝菌素的结合模式。