title: [Effect of deprotonation on the conformational state of the tetracycline molecule].
abstract: Conformation rearrangements in the tetracycline molecule under the effect of the aqueous medium pH were investigated by circular dichroism and absorption spectrophotometry. Possible causes of the changes in the spectrum after the molecule deprotonation are discussed. An increase in the pH value was accompanied by folding-unfolding of the A-ring of the tetracycline molecule and its transfer within the pH neutral ranges to the conformation close to planar one and after increasing of the aqueous solution polarity to the folded conformation. The BCD chromophore did not change its initial flat conformation during deprotonation. The loss of the proton (4) by the nitrogen atom was accompanied by changes in the A chromophore chirality.
authors.forename: V I
authors.initials: VI
authors.lastname: Grosheva
mesh_terms: D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D008968:Molecular Conformation; D015394:Molecular Structure; D011522:Protons; D013053:Spectrophotometry; D013754:Tetracyclines / Q000737:chemistry*
chemical_list: D011522:Protons; D013754:Tetracyclines
vernacular_title: Vliianie deprotonirovaniia na konformatsionnoe sostoianie molekuly tetratsiklina.