- 2D NMR, FT-IR, ESI MS studies and DFT, PM5 semiempirical calculations of new benzoic semduramicin anhydride and their complexes with selected monovalent cations
-
A new benzoic semduramicin anhydride (SemBz) was obtained. The new compound and its ability to form complexes with monovalent cations was studied by the ESI mass spectrometry, DFT, 2D NMR and FT-IR spectroscopic methods. The FT-IR spectra indicate that the K+ cation in SemBz complex is localised. However, Li+ and Na+ cations in SemBz complexes undergoes fast fluctuations between oxygen atoms inside the cavity of the molecule. These observations were compared to the behavior of semduramicin salts with these cations. The structures of all salts and complexes obtained were calculated by the PM5 semiempirical method. All results are in agreement with the spectroscopic data and allow visualisation of SemBz structure and its complexes with monovalent cations.
- Pankiewicz, Rados?aw
-
-
Read Online
- Synthetic modification of a novel microbial ionophore: Exploration of anticoccidial structure-activity relationships
-
While fermentation-derived polyether ionophores such as salinomycin are the dominant class of anticoccidial feed additives, there is little information concerning the structural features which confer optimal potency/efficacy in this important series. The recently discovered microbial polyether 1a, featuring potent, broad-spectrum anticoccidial activity, was employed as a template to explore structure-activity relationships. A number of single-step synthetic modifications targeted structural changes in both the lipophilic carbon backbone and the ion-binding cavity of 1a. Although previous semisynthetic transformations among the polyether ionophores almost always resulted in a substantial loss of anticoccidial activity, we obtained several analogues, altered on the periphery of the ionophore-ion complex, which retain good potency and efficacy. Monoglycone 7 (semduramicin sodium) has the most impressive anticoccidial profile of this series, and is undergoing further biological testing under field conditions.
- Glazer,Koss,Olson,Ricketts,Schaaf,Wiscount Jr.
-
p. 1839 - 1844
(2007/10/02)
-