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Updated: Oct 13, 2026

Nanomechanics of Drug-target Interactions and Antibacterial Resistance Detection
Published on: October 25, 2013
Conformation of antibiotic X-537A (lasalocid-A) and its calcium complex in acetonitrile solvent using circular
Abstract:
The calcium binding characteristics of antibiotic X-537A (lasalocid-A) in a lipophilic solvent, acetonitrile (CH3CN), have been studied using circular dichroism (CD) spectroscopy. The analysis of the data indicated that in this medium polar solvent, X-537A forms predominantly the charged complexes of stoichiometries 2:1 and 1:1, the relative amounts of the two being dependent on [Ca2+]. The conformations of the complexes, arrived at on the basis of the data, seem to indicate a rigid part encompassing Ca2+, liganded to 3 oxygens of the molecule, viz., the carbonyl, the substituted tetrahydrofuran ring and the substituted pyran ring oxygens (apart from, possibly, the liganding provided by nitrogen atoms of the solvent molecules), and a flexible part consisting of the salicylic acid group of the molecule.
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