標題: Magnesium and calcium reveal different chelating effects in a steroid compound: A model study of prednisolone using NMR spectroscopy
作者: Carillo, Kathleen D.
Wu, Danni
Lin, Su-Ching
Tsai, Shen-Long
Shie, Jiun-Jie
Tzou, Der-Lii M.
應用化學系
Department of Applied Chemistry
關鍵字: Prednisolone;NMR;Cation chelation;Conformational change;Calcium;Magnesium
公開日期: 1-十月-2019
摘要: In this work, we used high resolution NMR spectroscopy to investigate metal cation chelation by the steroidal drug 1,4-pregnadiene-11 beta,17 alpha,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 H-1/C-13 heteronuclear correlation spectroscopy, we were able to resolve most of the H-1 signals, except those at 1.4-1.55 ppm, where signals for H15 beta, H16 alpha and Me-19 are superimposed. The chelation sites were determined by the cation concentration-dependent C-13 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 (3)J(H)(-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.
URI: http://dx.doi.org/10.1016/j.steroids.2019.108429
http://hdl.handle.net/11536/152784
ISSN: 0039-128X
DOI: 10.1016/j.steroids.2019.108429
期刊: STEROIDS
Volume: 150
起始頁: 0
結束頁: 0
顯示於類別:期刊論文