Solid-state NMR of bisphosphonates adsorbed on hydroxyapatite

Citation
G. Grossmann et al., Solid-state NMR of bisphosphonates adsorbed on hydroxyapatite, MAGN RES CH, 38(1), 2000, pp. 11-16
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
MAGNETIC RESONANCE IN CHEMISTRY
ISSN journal
0749-1581 → ACNP
Volume
38
Issue
1
Year of publication
2000
Pages
11 - 16
Database
ISI
SICI code
0749-1581(200001)38:1<11:SNOBAO>2.0.ZU;2-R
Abstract
Solid-state P-31 and C-13 magic angle spinning (MAS) NMR spectra were used to characterize pure bisphosphonates and also bisphosphonates adsorbed on h ydroxyapatite. Four geminal bisphosphonates, including the clinically used compounds ethane-1-hydroxy-1,1-diphosphonic acid, 3-amino-1-hydroxypropane- 1,1-diphosphonic acid and 4-amino-1-hydroxybutane-1,1-diphosphonic acid, fi ve alpha,w-bisphosphonates and phosphonoacetic acid were investigated. NMR spectra of pure and adsorbed bisphosphonates differ in the observed linewid ths and in the isotropic chemical shifts. The broad lines reflect mainly th e poor crystallinity of the adsorbed compounds. Shifts of delta(isos) in bo th directions do not reveal a correlation with the molecular structures. Th e molar ratio of phosphonates adsorbed on hydroxyapatite determined by P-31 spectra without cross-polarization (CP) is approximately two times larger for geminal bisphosphonates than for ol,w-bisphosphonates and phosphonoacet ic acid. C-13 CP/MAS spectra of pure and adsorbed bisphosphonates recorded in two cases for identification of adsorbed compounds give additional infor mation about the state of adsorbed compounds. Disodium a,w-dihydroxypolymet hylene-alpha,w-bisphosphonates in the solid state show characteristic C-13 chemical shifts which are indicative of either odd or even numbers of CH2 g roups. Copyright (C) 2000 John Wiley & Sons, Ltd.