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Adult Zebrafish Injury Models to Study the Effects of Prednisolone in Regenerating Bone Tissue
Published on: October 18, 2018
Magnesium and calcium reveal different chelating effects in a steroid compound: A model study of prednisolone using
Kathleen D Carillo1, Danni Wu2, Su-Ching Lin2
1International Graduate Program, SCST, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC; The Department of Applied Chemistry, National Chiao-Tung University, Hsinchu 30013, Taiwan, ROC; Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
Abstract:
In this work, we used high resolution NMR spectroscopy to investigate metal cation chelation by the steroidal drug 1,4-pregnadiene-11β,17α,21-triol-3,20-dione (Prednisolone; abbreviated as Prd). Prd/MgCl2 and Prd/CaCl2 mixtures were prepared at eight different molar ratios. Using two-dimensional 1H/13C heteronuclear correlation spectroscopy, we were able to resolve most of the 1H signals, except those at 1.4-1.55 ppm, where signals for H15β, H16α and Me-19 are superimposed. The chelation sites were determined by the cation concentration-dependent 13C signals. Both ring A and ring D of Prd were found to be involved in Mg2+ chelation, whereas only ring A was involved in Ca2+ chelation. The dihedral angles deduced from the 3JH-H coupling constants indicated that ring D of Prd might undergo rather small, but different, distortions in the presence of Mg2+ and Ca2+. Additionally, using the continuous variation method, we deduced that the stoichiometric ratios of the Prd/Mg2+ and Prd/Ca2+ complexes were 1:1 and 2:1, respectively. All of the evidence led us to conclude that the Prd/Mg2+ and Prd/Ca2+ complexes are mediated by different chelating mechanisms.
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