A physicochemical study of the tetracycline coordination to oxovanadium(IV)

Citation
Fcs. De Paula et al., A physicochemical study of the tetracycline coordination to oxovanadium(IV), J INORG BIO, 76(3-4), 1999, pp. 221-230
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics","Inorganic & Nuclear Chemistry
Journal title
JOURNAL OF INORGANIC BIOCHEMISTRY
ISSN journal
0162-0134 → ACNP
Volume
76
Issue
3-4
Year of publication
1999
Pages
221 - 230
Database
ISI
SICI code
0162-0134(19990930)76:3-4<221:APSOTT>2.0.ZU;2-8
Abstract
The interaction of tetracycline and oxovanadium(IV) in aqueous solution was studied by potentiometric and spectrophotometric methods. Oxovanadium(IV) ions form both a positively charged 1:1 and a neutral 2:1 metal-ligand comp lex with tetracycline. When a 1:1 ligand-to-metal ratio mixture is used at about pH 4.5 the 1:1 species predominates, being replaced at pH 6 by the bi nuclear complex. The binuclear complex has been isolated and fully characte rised, Infrared and EPR studies suggest the existence of two distinct vanad yl binding sites. Our results indicate that the first vanadium coordinates to the BCD-ring system and the second one to the A-ring. Biological implica tions of the existence of a neutral complex at physiological pH are briefly discussed. (C) 1999 Elsevier Science Inc. All rights reserved.